Thermal Spray Coatings | Technology and Practice

Stripping Knife Edge Seal Coatings

2011-12-24T07:57:00.000-08:00

One may already know that plasma sprayed coatings are quite common in knife edge seals used in the aero-engine industry. These knife edge seals are a critical component in aircraft engines and are generally coated with an abrasive coating. They are used to form a seal for the gas flows and form a mating surface with an abradable coated surface. That is one of the beauties of the thermal spray coating process. You can thermal spray one part with an abrasive material and coat its mating part with an abradable material. Is that neat or what? Sorry, got carried away praising the process.

The abrasive coating used on knife edge seals is generally plasma sprayed aluminum oxide – titanium oxide over a bond coat of nickel-aluminum. The coating thickness of the bond coat is usually two to four thousandths of an inch and the top coat is usually anywhere from four to twelve thousandths of an inch thick. Coating these knife edge seal components can be very interesting indeed, with almost no one that does it manually. Automation is a virtual necessity in this case. While the nickel-aluminum-alumina-titania is the most common, there are also knife edge seals that are coated with chrome-carbide-nickel-chrome; in this case the coating thickness generally runs around five thousandths of an inch thick.

There are a variety of reasons why one might have a need to strip these coatings. Without getting into too much of a discussion as to the reasons for the stripping, the quick ones that come to mind are A. standard overhaul and repair procedure and B. One of the million reasons for quality discrepancy. And in this article, we will consider the method of stripping such coatings.

Grind stripping is a very very expensive route and generally not considered at all due to the configuration of these parts. Grit blast stripping can destroy the knife edges and then you have a component that becomes unusable. The best method to strip plasma sprayed coatings on knife edge seals is therefore ( do I hear a drum-roll ……) chemical stripping.

In the case of plasma sprayed alumina-titania over nickel-aluminum types, one might want to consider dipping in a hot diluted acid bath. What this does is that the acid gets through the porosity of the top coat and removes it away from the bond coat. Once this is done, the component needs to be washed with water and then dipped in a hot diluted alkaline bath to attack the bond coat material. After the coating is removed, rinse the part with water and then a gentle abrasive dust blast followed by a glass bead blast operation could be considered.

In the case of plasma sprayed chrome carbide nickel chrome coated seals, about the only method that might work is electrolytic stripping using electricity in an electrolytic bath that is generally aqueous alkaline material. The process takes a long time to complete but then such parts are very expensive to manufacture anyway.

As you may have noticed, what is presented above is basic chemistry. One will have to develop the proper dilution ratios, proper temperature settings and time in the solution parameters before claiming to be an expert. Additionally, one of the most important aspects to consider is the ability of the base material to withstand the chemical environment. If the chemicals used to strip the coating attacks the base material too, then it becomes meaningless. Testing and experimenting on sample hardware is highly recommended. An additional point to consider is to evaluate the sample material ( which incidentally must be the SAME as the actual hardware ) by testing metallurgically for evidence of any intergranular attack after the stripping process. This kind of attack greatly reduces the metallurgical integrity of the component and no evidence of such attack is permissible.

Of course, once the stripping is successful, the part can go back to the normal re-coating procedure which will involve everything including starting with incoming inspection. There are a variety of other parameters to be considered also. For example, how often can the solution be used before it gets depleted: secondly how often can one simply add acid or caustic before the bath is basically spent. In the case of electrolytic stripping, obviously current and voltage parameters need to be developed also.

Regardless of the stripping process used, it is of imperative importance to get your customer approval before you go around dipping your customer hardware into chemicals. And process approval must include all the details of the stripping process including all key parameters. And parts that have been stripped and re-coated must be identified and marked as such for traceability reasons. Hardware safety is of paramount importance in the aerospace industry and no short cuts are allowed.

Of course, the easy solution ( no pun intended ) is simply to send out the hardware to a firm that specializes in coating removal rather than doing it in-house. This is something to evaluate also from a business stand-point depending upon the volume of stripping that is involved. Because there are other hidden costs such as hazardous waste disposal costs and environmental compliance costs that need to be considered. That is where technology meets regulations.. isn’t that wonderful !

Self release coating episode

2011-12-20T14:27:00.000-08:00

In this post, I would like to tell a short story that reinforces the old adage that necessity is the mother of invention. This is where the smaller thermal spray coating houses differ from the larger, more affluent ones. The larger coating shops with their elaborate engineering staff, well-stocked tool rooms, possibly an in-house machine shop and a bottomless purchasing budget can certainly run circles around those that operate on shoe string budgets; but you know what, the stories that come out of smaller, leaner thermal spray houses are a lot more interesting than the mega-box type facilities.

In this regard, there was once upon a time a small thermal spray coatings facility that came up with the idea that utilizing the inherent porosity of plasma sprayed coatings, one could infiltrate with a silicone polymer, cure it and then use the resulting coating as a self-release coating that can be used in components used in the adhesive printing and adhesive handling machinery. This sounds like a good idea and so they started putting their heads together in developing this system.

So, for the plasma sprayed coating, they settled for NiCrAlY material such as those sold by millions of powder vendors. They made sure that the parameter sheet called for a little bit more of an aggression with the air jets cross over so that the coating will be little bit more porous in the range of about twenty five to thirty percent porosity. Then as far as the silicone polymer is concerned the best one that they could come up with was an ultra-violet light curable one part material that comes in a liquid form. This was to be sprayed with a simple cheap air brush gun available for less than a hundred dollars.

Then they started looking for ultra violet lamps and these things could become really expensive; the cheapest one that had any power whatsoever was about three thousand dollars. And so the developer got frustrated and dejected. But then if you are going to quit at the first sight of a problem then you do not belong in the thermal spray industry, right. As an old foreman used to say – if it feels too hot then get out of the kitchen: you do not qualify to be a cook.

After shopping for cheaper brands, the idea hit him right in front of his nose. After all the plasma gun puts out quite a bit of uv itself. Remember all those burn marks in your arms from standing all day without proper clothing? So what he did was to coat the parts: then stop: spray the silicone: then simply turn on the plasma torch and let it cure the silicone. The system and the procedure worked every single time and he did not even have to spend any extra money buying silly ultra violet curing lamps.

So the moral of the story is that we should always be having our thinking cap on and problems can be solved.

Thermal spray blog update

2011-12-18T05:23:00.000-08:00

First of all, a big offer of thanks to all visitors of this thermal spray blog. You know the thermal spray industry, as exciting as it is, and is filled with superb engineers, operators and other support personnel does have a plethora of sources for reference purposes, be it thermal spray magazines, thermal spray conferences, meetings, expositions and such. And for the hardcore thermal spray engineer, there are numerous technical reference books and technically advanced thermal spray journal articles. This blog does not even come close as a reference tool; and I do not claim in any way , shape or form to be offering that kind of content.

But like all things in life, one needs a little diversion every once in a while albeit within the confines of his or her interest. Just like the classical music fanatic that likes to listen to rock music or hip-hop once in a while ( I wonder what other genre of music Mozart would have listened to if he were alive today.. ), or the serious literature professor that teaches Victorian era English literature, that likes to read a book of fiction by J.K.Rowling, this blog hopes to bring that gush of fresh air to the thermal spray coatings fanatic. And if it has done that, then that is well and good. In fact, a lot of this is summarized in my post entitled **** thermal spray blog layout **** You might want to check it out.

And now, a confession. I have not updated here for quite a while now and that is by no means because I have lost an interest in the plasma coatings field or in writing anything for that matter. I love engineering, I love coatings and I love writing. However, a million other things that were left behind unattended, a million other things that had to be done and a million other responsibilities kind of took up every bit of spare time that came my way. I am sure you all can associate your own lives with what I am saying. How often have you wanted to update those old thermal spray operation sheets, re-organize your plasma powders crib, re-organize your sales brochures, re-train your thermal spray operators, re-evaluate your company goals, visit that old faithful customer that keeps sending you parts to coat every month ( and you have been taking him for granted ! ) and so on and on, but never really got around to doing it! That is pretty much what has consumed me. And you know, I am a human being just like others and so I am going to have to write a letter to the Man upstairs asking for more hours in the day!

And you know, so many global events have taken place in recent times that thermal spray coatings business owners need to learn from and apply to their own businesses. We need to be talking about all these soon. And we will. And since the beginning of this blog, all of us have grown a little older, and hopefully wiser and therefore can perform our duties a little bit better than years ago. Just as wine gets better with age, those in the thermal spray coatings business need to get better with age! And this is applicable to all, regardless of which aspect your main duty deals with, be it operations, engineering, sales or management.

What I am seeing is that the thermal spray industry has truly become global, with exchange of ideas happening all over the earth. I can see it from the visitors to this tiny blog that comprises people from all the continents, many of whom have asked questions and many of whom have simply spent some time reading and learning about what other companies are advertising and their products and so on. And so, in a way, the thermal spray industry deserves some credit for bringing the people of the world together in its own way!!

Thermal spray stripping methods

2010-10-03T09:04:00.000-07:00

In a previous post, we dealt with the reasons for stripping thermal sprayed coatings. You may have concluded from there that the reasons for stripping thermal spray coatings are not necessarily the fault of the flame spray coatings operator, but sometimes stripping and thermal spray re-coating of hardware is by design as in the case of overhaul and repair components used in the aerospace industry.

In this post, however, we will deal with the options available for the stripping of thermal spray coatings, giving the thermal spray engineer a choice in this procedure. Some options may be simply ruled out from a technical standpoint, some may be ruled out from a facilities stand point and some method of coatings stripping may be somewhat better economically as opposed to others.

Method number one: Grit blast stripping of thermal spray coatings.

As one might very well know, grit blast is used as a surface preparation method prior to the application of thermal spray coatings. While this is true, grit blasting procedures can also be used to strip thermal spray coatings. Obviously, the key characteristic to be considered is the uncoated dimension of the part not to be violated. Thus it is essential that the thermal spray engineer read the blue print and indicate to the grit blast operator and in-process inspector to measure the part dimensions at intervals to ensure that the part dimensions are not violated.

A key problem occurs when using this procedure to strip thermal spray coatings from thin walled components because they may tend to warp during the stripping process. Additionally if you are a quality thermal spray coatings house, then you must ensure that excessive grit blast inclusions are not resulting in the actual hardware because if this happens then the subsequent re-application of the thermal spray coating may violate the grit entrapment limits of the applicable specifications. This is not to be taken lightly by any means. This means that the grit blast stripping parameters need to be not excessively aggressive.

To overcome this, every thermal spray shop that plans to use grit blast stripping of thermal spray coatings, must develop such parameters on various commonly used substrates and commonly applied coatings for their customers ahead of time, and evaluate them in the metallurgical laboratory for effective coatings removal without excessive grit entrapment, so that when the actual time comes to strip real hardware, one knows what he is doing.

Method number two: Grind stripping of thermal spray coatings

Grind stripping of thermal spray coatings is another option at the disposal of the engineering team. While this may seem like an easy alternative, it comes with its own set of headaches and parameter controls. As before, dimensional controls are very important and must be adhered to. Additionally, proper coolant usage is imperative if called for. Wheel dressing requirements, proper wheel designations, etc are a given. Thermal spray shops sometimes perform coat and grind operations in-house and in such cases the quality controls are much superior because they do this day in and day out. If this is going to get outsourced then ensure that the outside vendor is has the necessary experience and expertise dealing with grinding thermal spray coatings, otherwise there might be nothing but problems to deal with.

Method number three: Chemical stripping of thermal spray coatings

Chemical stripping of thermal spray coatings is quite an effective method depending upon the chemistry of the coating AND the chemistry of the substrate. While the chemical solution might be quite effective in eating away the coating material, it MIGHT eat away at the substrate material too. I know this previous statement sounded quite non-technical, but that is the best way I could drive home the point that the combination of the coating material AND the substrate material needs to be considered when using this procedure.

Chemical stripping of thermal spray coatings is quite a detailed topic in itself and we will be dealing with it quite extensively in future posts. This is an introductory article for the stripping methods and hence just a cursory glance is what we are interested in presenting here.

There are two basic kinds of chemical stripping: one is standard dipping of the parts in a chemical solution that is sometimes heated and the other is electrolytic stripping where there is electric current passed through the solution wherein the part itself forms an electrode. There is an array of safety procedures and quality control aspects of the stripping solution itself that need to be watched out for. Additionally, intergranular attack of the base metal by the chemical solution must be evaluated for. Such intergranular attack can cause a weakening of the hardware and is many times not acceptable per specifications. More about this in future articles.

In summary, there are options available to the thermal spray engineer when considering stripping of coatings. These methods can be used on actual hardware as well in hard tooling components. Needless to say sophisticated analysis of intergranular attack and such are not needed for hard tooling components but are definitely needed for actual customer hardware, especially rotating parts.

Thermal spray stripping reasons

2010-08-07T07:36:00.000-07:00

In the ideal world, thermal spray coatings shops are to apply coatings once on to the surface of the workpiece, ship it to the customer, bill them and get paid with both the customer and the supplier in a state of happiness. In such a world, the question of stripping and recoating thermal spray coatings does not exist. However, in the real world, that is not always the case. There are numerous instances when a thermal sprayed surface needs to be stripped and the part re-coated. It is the purpose of this post to identify the reasons behind stripping and recoating thermal sprayed parts. The order in which the reasons are listed do not conform to any heirarchy. Additionally, please note that we will be dealing only with stripping and re-coating thermal sprayed coatings on actual hardware. That is, we will not deal with the stripping of hard tooling used in the thermal spray processes. As you may know, often hard tooling maintenance involves stripping the tooling of any overspray catches and bringing back the tooling to its original state so that proper masking and shadowing is still accomplished.

Reason number one: The wrong surface got flame sprayed While some thermal spray coatings shop owners may not admit to it, this is a problem that I have seen happen more than once in my career. Sometimes the print was read incorrectly and the wrong instructions were sent to the shop floor. This is different from the case wherein the right instructions were sent but the masking, grit blasting operators etc read the instructions incorrectly. Many times this latter situation gets rectified if you have an in-process inspection in place that verifies if the masked area is exactly per what the operation sheet calls for. Well, if the engineering instruction itself was incorrect, you have no choice but to strip and re-thermal spray the right area.

Reason number two: The wrong thermal spray coating material was used. This has happened in my career too. In a real life example, the print called for a twelve percent yttria stabilized zirconia, but the part ended up getting a plasma spray coating of eight percent yttria stabilized zirconia. The customer was contacted to see if they would accept the part on a deviation request since they were both thermal barrier coatings, but the customer said no. And so stripping and recoating was unavoidable. Such errors can be minimized if the powder control room technician is over careful. Companies where this has not happened should really pat such technicians on the back – they are usually the unsung heroes.

Reason number three: The incorrect process was used. This can happen in thermal spray coatings houses that perform a variety of processes. And this is more apt to happen with certain coatings that are coatable by different processes. An example will make this clear. Tungsten carbide cobalt aggregates can be sprayed by HVOF processes as well as plasma coating processes. The same is the case with cobalt-chrome-molybdenum-silicon powder such as the well known T-800. The chance of this happening with alumina-titania is virtually non-existent since it is generally coated only by plasma. And as one may know, T-800 coated by HVOF is much different from T-800 coated by plasma. And in such a case, one has no choice but to strip and re-coat.

Reason number four: The thermal sprayed coating does not meet the customer’s metallurgical quality specifications. This encompasses the entire range of metallurgical specifications including but not limited to porosity, grit blast interface contamination, micro-hardness, macro-hardness and tensile bond strength requirements. These can be minimized ( but not completely eliminated ) by a rigorous thermal spray booth release procedure. This will ensure that the booth is operating in the best operable condition for the coating at hand. This does not ensure that every single part in the batch will meet the requirements. For example, the booth release coupon may have met all of the metallurgical lab requirements, however, half way through the coating process, the powder feeder noticeably started malfunctioning with tremendous surges in feed rate resulted in potentially high levels of unmelted particles, etc resulting in the coupon coated with the part failing quality. In this case, the part may have to be stripped and re-coated.

Reason number five: Thermal spray coating thickness violates customer specifications. This may have been determined with simulated part samples that are coated with the part or by non-destructive fisher scope readings or even standard caliper readings. If the coating thickness is above max or non-uniform, then the part becomes a candidate for strip and re-coat.

Reason number six: There are cases by design where thermal spray strip and re-coat are required. An example is the case of overhaul and repair components in the aircraft engine industry. In the engine overhaul and repair industry, the FAA repair manuals may call for an engine run component that has had thermal spray coatings to be stripped of them and re-coated as part of the refurbishment process. This is a lucrative industry by the way for those in the thermal spray industry that have a great quality system in place and have oem approvals by the major players in the industry.

As you can see above, there are at least half a dozen reasons why thermal spray stripping and re-coating is a possibility in the every day life of a thermal spray business. In a future post, we will discuss more about the stripping processes themselves and the things to be careful about and watch out for.

Thermal Spray Coatings Quality

2010-03-27T15:33:00.000-07:00

The title of this post may seem rather quite exhaustive or quite mundane depending on which way you look at it. After all if you are involved with the quality control function of a thermal spray coatings facility, you might think it is quite exhaustive. On the other hand, if you are an accountant in a thermal spray coatings shop, you might think it is not only quite mundane but also quite a revenue draining function. While I can sympathize with the feelings of the accounting function in thermal spray shops and for that matter in all manufacturing industries, I am an engineer at heart and you know I will always side with the other side!

And this is not without rhyme or reason either. The very reason why I decided to write about thermal spray coatings quality as a post in itself is what I learnt from the recent news involving Toyota. As a matter of fact, I could write an entire blog with tens of posts that involve thermal spray coatings quality. But for now, I will try to limit myself to this one single post.

Toyota quality was considered infallible in manufacturing circles. Yet even giants can face quality problems. This is a wake up call to all personnel in all thermal spray coatings facilities worldwide to stop, take a deep breath and re-evaluate EVERY single aspect of processing in your facility from a quality standpoint.

This is especially important in the field of thermal spray coatings because as you may know, the largest market for thermal spray coatings is in the aerospace industry where people count on the quality of flight hardware for their very lives. A spalled massive piece of coating can cause significant secondary damage to turbine engines; and if people’s lives get affected, it does not matter who you can point the finger at – it is already too late.

Re-evaluate engineering, maintenance, production, quality control systems, quality control personnel and so on. Talk about quality control personnel, make sure their eye exams are performed annually – the last thing you want is an inspector checking for cracks by visual inspection and he cannot even see the ten fingers he has from an arm’s distance! Metallurgical laboratory procedures need to reviewed. And I don’t care if you have already passed your NADCAP or ISO audits successfully – do it for your company’s own sake and not for the sake of some outside certifying agency.

And quality re-evaluation should not stop with only your own facility. You need to ensure that the purchased goods you get involved with are also well controlled. This involves ensuring the quality of thermal spray powders, masking materials, purchased gases and so on. Sure, it is going to cost a lot more to do business; but the cost of bad quality hardware could simply put you out of business.

As you may have seen with the Toyota debacle, would you rather clean up your own house before calamity strikes or wait for the agents from the FAA or NTSB show up at your company and start pondering through hundreds and thousands of pages of operations sheets, shop travelers, quality documentation and myriads of other data if you are found guilty of shipping bad hardware. And thank God Toyota is not in the business of aerospace goods. Good Lord, you surely are ( most likely ), now that you are in the thermal spray coatings business.

By the way, were any of you planning on putting thermal spray wear coatings on accelerator pedals for Toyota ! Just kidding !

Thermal Spray Grit Blast

2009-08-17T11:37:00.000-07:00

Thermal spray engineers everywhere know of the myriads of variables that can affect the outcome of the process from the stand point of quality. This is because the thermal spray coating process itself is built up of various sub-processes, each of which has its own set of variables and therefore problems. It IS the job of thermal spray coatings process engineers to pay specific attention to EACH of these sub processes and institute proper controls on each of them in order to ensure final product quality.

It is my opinion that none of these sub processes can be taken for granted and none of them is either more important or less important than the other. I know, as must you, that in many thermal spray coatings houses, the plasma spray operator is generally considered the king ( or the queen to be politically right ) in comparison to the parts cleaning operator and this is not correct from a processing stand-point. Everyone is equally important and I do not mean this from a socialism stand-point but rather from a technical point of view.

Grit blasting prior to thermal spray is one such sub-process that is very important in itself. The variables dealing with proper grit blasting cannot be over emphasized. You do want the proper grit blast coverage and the appropriate level of grit blasting, but not over grit blasting by way of too high a grit blasting pressure or too aggressive a grit size. I know of thermal spray coatings companies that require their operators to have a grit blast release coupon at the beginning of every job that gets tested for proper surface roughness measured by way of a profilometer and that is the right way to ensure that the surface has been properly prepared.

Grit blasting is a key link in the overall thermal spray process because at the very heart of proper adhesion is a properly prepared surface. Grit blasting prior to thermal spray is considered a *significant process* by many OEM aerospace companies and rightfully so, because thermal spray is inherently a mechanically bonded phenomenon other than in cases where a diffusion heat treatment is followed up.

Personally, the variables in grit blasting are so many and the process itself can become problematic at times that I felt that it deserved a separate blog all by itself and you are welcome to visit my blog on abrasive grit blasting entitled http://abrasivegritblasting.blogspot.com wherein I plan to discuss not only grit blasting as a surface preparation process prior to follow on processes but also as a means of coating removal. ( Of course, some of us will claim never to have had a need to strip and recoat, right? wink, wink ) Anyway, that is another site that you may want to visit in your spare time.

Thermal spray companies that perform shot peening have another headache to deal with; I guess that is why they pay them the big bucks :) But shot peening becomes another process with variables that need to be controlled and monitored.

A case in point to be remembered if you are planning to institute grit blast cabinet release by way of coupon control, ( if you have not already done so far ) is to ensure that the coupon base material is the SAME as the part base material, otherwise the results wont mean much.

Thermal spray coatings applications

2009-08-08T06:34:00.000-07:00

Every thermal spray coatings company wants increasing profits quarter after quarter and year after year. After all that is what every business strives for and why would the thermal spray coatings business be any different. And so, year after year marketing personnel put up goals and sales figures to be accomplished; some of whom do a really great task of breaking down the larger objectives to smaller pieces and then assign individual thermal spray coatings salesmen to go out and drum up more business one way or the other.

But it is not sufficient simply to put up sales targets and beat up on salesmen. While that may work for thermal spray companies that have not had any significant sales efforts in the past, for those that are more mature in this industry, simply cutting the price of plasma coating services is not necessarily the most profitable way to increase sales. In my opinion, marketing people will need to work closely with thermal spray engineering people in order to bring in new jobs at the highest profit levels possible.

This can be accomplished by finding new thermal spray coatings applications. We all know about wear resistance, thermal barrier, abradable, abrasive, anti-galling and other phenomenal characteristics that can be invoked on to the component surfaces. What is needed is for salesmen to go out and solve customer problems using thermal sprayed coatings in applications where they have not even been considered. That is the way that higher prices can be obtained for the services performed. Simply going after knife edge seals and thermal barrier coatings on burner cans is a sure path to frustration because every coatings house is going after these. You need to go after newer thermal spray coatings applications.

That requires a phenomenal amount of effort up front. For example, I once came across a company that was interested in putting on a wear resistant surface on bars used in the extraction of oil from corn. They were using plasma transferred arc welding on these barrel bars. The problem they were encountering was distortion of the bars during the welding process. I recommended changing over to twin wire arc spray using a Tafa wire and believe me it worked like a charm and we ended up coating thousands of these bars. As a side note, there were no Nadcap audits to go through to get certified to coat either

Similarly, one could take a basic nickel chrome aluminum yttrium coating such as Metco 443 and then impregnate it with some material and you will end up with a unique coating with unique properties that you may find applications for in some industry that others have not been to and you can pretty much name your price. Development of new thermal spray coatings applications is the key to increasing sales and bringing in profitable jobs and not just dogs.

Thermal Spray TBCs porosity

2009-07-14T16:27:00.000-07:00

Thermal spray coatings are inherently porous in nature. The porosity levels in certain thermal sprayed coatings such as CoNiCrAlY coatings performed by the low pressure plasma sprayed process may be much lower than its corresponding plasma sprayed cousin, but nevertheless porosity is a given. Ok, some hvof fans could join in the lpps group, but only in the tail end.

Nevertheless, porosity in thermal sprayed coatings is not all that evil when it comes to thermal barrier oatings. On the contrary, a certain level of porosity IS required of all thermal barrier coatings for them to function properly and that is one reason why thermal sprayed coatings processes are preferred in the application of these materials such as yttria stabilized zirconia.

The ability of a thermal barrier coating to withstand thermal cycling is very much dependent upon this inherent porosity. Plasma sprayed TBCs generally are required to have about fifteen percent porosity levels in their microstructure. This is what gives them their thermal cycling strain tolerance. But there is a significant culprit that can mask the actual porosity levels in these TBCs.

Those that are familiar with such coatings will know that it is pullout as observed in metallographic testing. Such pullout is many times wrongly diagnosed as porosity, but is caused by improper polishing techniques. Conversely, improper polishing techniques can smear over the coating and give you a lower porosity observation. Thus the importance of metallurgical polishing techniques cannot be overstated.

Metallurgical polishing that either overstates or underestimates the actual porosity in TBCs is very dangerous. Even with automatic polishers, it is the establishment of a proper polishing procedure that is imperative, especially in the case of TBCs. Computerized image analysis that is touted by some companies is great in establishing real numbers, but then again the sample preparation technique is not a variable that these gizmos can fix.

The porosity level of such TBCs is more important in certain service cycle components than in others. For example, a TBC coated component that is in a high temperature furnace that ramps up to a high temperature and stays there for very long periods of time does not cycle much and so a lower porosity may not affect its life that much. Same is the case with a jet engine component that flies across the atlantic between two far away continents as opposed to a commuter plane engine that starts and stops every hour or so and cycles to high and low loads often.

Unfortunately, the thermal spray coater that is the applicator of the coating is not privy to this information and so it is in his or her best interests to meet the necessary specifications every single time and not take a gamble with the end use of the component.

Thermal spray and furnace charts

2009-06-11T12:55:00.000-07:00

That the biggest customer for thermal spray coatings is the aerospace industry is very well known. Of course thermal spray coatings are used in other industries too such as ground based gas turbines, paper and printing, pump and valve and other commercial industrial applications. But the aerospace industry accounts for a major portion of thermal spray coatings sales. And the aerospace industry is very strict when it comes to quality control expectations of its thermal spray coatings applicators. Conversely stated, if you are a thermal spray coatings vendor and are either performing work currently for the aerospace industry or are envisioning getting into the aerospace thermal spray coatings applications, quality control has to be high on your mind.

This is where I find a one thing lacking in SOME thermal spray coatings contractors that deal with the aerospace industry and even SOME quality auditors from customers whose task it is to ensure that the flame spray coatings vendor is adhering to and potentially going beyond the requirements of the specification. After all, that is what separates a good thermal spray coatings vendor from a so-so contractor. And so, in this post, we will discuss the quality aspect that I have been alluding to above. And that has to do with furnace charts.

Now, for the most part, thermal spray coatings engineers claim they never deal with furnaces and therefore furnace charts are foreign to them. Not so, I say. Every time you send a coated part for diffusion heat treatment, such as an aluminized part, you need a furnace chart. Well, we don’t do any aluminizing one may claim. Fair enough. Now, every time you put a set of bond slugs into an oven to cure, you are dealing with a furnace and therefore you DO need a furnace chart and you should keep the furnace chart as part of the quality documentation and if you are an auditor, you should ask to see a couple of these charts to ensure that the bond slugs were in fact cured at the correct temperature and for the correct duration of time specified in the procedures.

Tensile bond slugs used for testing purposes are very important from a quality stand point and great care needs to be exerted to ensure the correct epoxy is used, the correct temperature of curing is used and the correct time is followed. And yet, some vendors do NOT keep the furnace charts with these slugs in their records.

There is another aspect dealing with the curing of tensile bond slugs in curing ovens and that is performing a uniformity survey of the furnace at periodically scheduled frequencies. Uniformity survey of the furnace is extremely important to ensure that the slugs are not being placed where the temperature of the oven is NOT what it is supposed to be.

So the next time you walk by the met lab in your company or the next time you receive bond strength results, ask for the furnace chart, ask for the uniformity survey and ensure thus that the bond slugs have been through a proper curing procedure; for if the test coupon is suspect, so are the test results!

Managing thermal spray innovation

2009-06-04T13:40:00.000-07:00

Managers at thermal spray coatings facilities usually have their plates full with the day to day operations and meeting the profitability demands placed by superiors. Some times this task of thermal spray management can get to be quite hectic dealing with suppliers of thermal spray consumables, dealing with customers who are always demanding more and more every day and above all dealing with employees who can sometimes turn out to be more vicious than the aforementioned two. To add to this problem comes quality issues, accounts receivables issues and so on.

But what is the hardest part of thermal spray coatings management? In my opinion, it is the management of thermal spray innovation. Innovation is the sure fire way in which you can stay ahead of your competition. Simply competing on price and delivery of thermal spray coatings services is a thing of the past. Everyone nowadays is willing to cut down their profit margins and some salesmen will even promise the unthinkable just to get in the door and snatch away the job that you have been plasma coating for years. They may find that they shot themselves in the foot months later, but in the mean time you have lost revenue from that thermal spray customer account and that is no fun.

Innovation on the other hand, can put you in a category all by yourself, far away from lousy competitors. And innovation in thermal spray coatings does not need to be relegated just to coming up with better parameters. Innovation can be in any area all the way from receiving to shipping and everything in between including new coatings development. But the issue of managing innovation deals not with innovation itself, but rather how you would handle the innovation and how you would motivate the regular employees to innovate every single day.

One cannot simply tell the employees, “Well you are getting paid everyday anyway and so any innovation you do is part of your job.” This may sound fine in theory, but in practice, no one will innovate for those terms. Then again, you cannot throw money every time someone comes up with an innovation. Complex calculations of how much money is saved for the company by a specific innovation or how much new business can be generated by a new idea sometimes create fierce emotional distress on the part of those that got less money than what they thought their idea was worth. I remember once when I was very young, I came up with something that I thought was worth three thousand dollars, but ended up with one hundred and forty seven; some motivation that was for me to come up with the next idea!

Creating, nurturing and maintaining an environment where new ideas are constantly being brought up by employees is the biggest challenge to any manager anywhere including those in the thermal spray industry. There is really no one time tested method that will suit every organization; and there is no one method of compensation and reward that will fit for every single company. Knowing your employees, what motivates them, what gets their juices flowing and what will keep them coming up with new ideas all the time is the most important task of any manager and arguably the hardest!

Thermal spray business blog

2009-05-31T09:41:00.000-07:00

People that have visited this site in the past know that what is dealt with here is pretty much anything that deals with the thermal spray coatings industry in general. In particular though you might have noticed that we deal with more of the slightly technically oriented and slightly day to day operations oriented articles that may be of interest to the thermal spray industry person. For example we have dealt with thermal spray robotics, thermal spray powders and other consumables, quality aspects of thermal spray coatings and so on.

And for the most part, besides providing some specific details off and on, I believe this is just interesting reading for the thermal spray engineer, operator or business person. After all, it is free and does not require any membership dues or other cash outlay requirements. I thought however, that there is a need to have a blog that is dedicated specifically to the business aspect of thermal spray coatings. And thus came http://thermalspraymoney.blogspot.com which is specifically geared towards the aspect of making money in the thermal spray coatings industry.

That blog deals only with the business of thermal spray coatings, be it accounts receivables, powders costing, costs of quality, re-work costs and so on. While the scientific and technical aspects of this technology are quite interesting, the bottom line of the thermal spray coatings company and for that matter any business is to make money. ( unless of course you get to be so big that the world cannot afford you to fail and so you may get bailed out by the taxpayer ) And so you are invited to visit http://thermalspraymoney.blogspot.com and get some interesting thoughts on the business aspects of the thermal spray business and who knows there might be an article or two there that might really interest you. Personally, I believe both these blogs go hand in hand and each one kind of compliments the other.

Thermal Spray Quality Auditor

2009-05-05T12:42:00.000-07:00

Years ago, I was in my second year of working at my first thermal spray coatings job. Being trained in engineering from an education standpoint, thermal spray engineering was of greater interest to me than other aspects of the business. Of course engineering and manufacturing are closely related and so I used to spend quite a bit of time in the thermal spray booth itself. And I always believed that to become a good thermal spray engineer, you must yourself spray parts. Only then can you engineer jobs well enough for the thermal spray operator to coat successfully without bitching at the engineering department. And I am sure most of you have heard this before.

But then this post is not about thermal spray engineering or production, rather about quality. Well that is where I was leading up to. I was told that we are going to have our monthly quality audit from a major aerospace company. And I figured that there will be a lot of pressure on the part of everyone to make sure that we passed this test. On the contrary, no one really seemed to be wound up about the event. Everyone went about their daily business as usual and I wanted to see how the thermal spray quality audit would be conducted. I had been in only one other quality audit in my thermal spray career at that point in time and that was a nightmare with the auditor pouring over piles and piles of paperwork in the quality manager’s office and people were being constantly paged to get this data and the other. And I thought to myself, oh boy this aint going to be fun and what about the fact that this auditor has been coming in once a month and I was not even aware of it up until then.

Well the auditor did show up a little after lunch time. I was asked to go with him and I was scared because I did not know the thermal spray quality jargon and so did not know what to expect. And what happened then completely blew my mind away and decades later I am still talking about it here and elsewhere. The auditor came in, I greeted him with a friendly smile. He reciprocated and said “ So it is your turn to watch me now. Are you ready?” I said “ I think I am. I don’t know.”

He said “ Okay, where are my parts running?”

I said “ Booths four and seven.”

“Lets go then.”

We went to thermal spray booth number four and thence to seven.

In both booths, the auditor took the traveler and the operation sheet and first checked to see if all prior operations were signed off, counted the parts in the booth and matched them against the traveler. Then checked the parameter sheet and verified that the operator was running the booth to the exact parameters that were specified in the process sheet, including amps, volts, stand off distance and so on. Next, he asked to go to the met lab and asked for the booth release samples for booths four and seven. Then proceeded to ask for the specification. The met lab person handed him the aerospace specification for the coating systems at hand, he verified the metallurgical characteristics of the booth release sample in regards to oxides, porosity, etc and then went to the powder crib and verified that the powder lot that the operator was using indeed had been formally released for spray, then looked at me and said “Good day, I am out of here. You are good to go ” And he was happy, signed the audit sheet as “Acceptable. Passed.” And he left. The whole thing took a little over an hour.

When he returned the next month, I had become a little bit more comfortable around him and so I asked him as to how come his audits were so simple and to the point whereas the other auditors usually caused so much commotion and noise. To which he replied – “ I am very much interested in making sure that the coatings you put on my parts are of the best quality. I am interested in hardware and so I want to witness that the operator is using approved powders and that his booth release microstructure is acceptable and that he is coating within specified parameters and so on. I am not interested in the paperwork bullshit and your quality ‘system’ nonsense. Make sure you give me good parts and make sure I get good hardware. I have peoples’ lives in my hand. These parts you are coating for me go into commercial aircraft engines. I cannot afford to have them fail. So I want to witness the actual quality in the booth. And that does not need to take up too much time.”

And I learnt a great lesson from this wise old sage and engineer.

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2009-05-05T12:18:00.000-07:00

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Thermal spray coatings variables

2009-04-04T08:43:00.000-07:00

What differentiates a high quality thermal spray coatings shop from a so-so quality thermal spray coatings shop, I was pondering the other day. Well, there are a bag full of variables that one can list that goes into producing high quality thermal spray coatings. The high quality thermal spray coatings facility most likely tries to keep these variables under tight control whereas the sloppy thermal spray coatings facility has poor controls on these variables. So if you want to convert your thermal spray shop from a low quality house to a high quality house, all you have to do is to simply put in more controls, right? Now that is simple. Yet why do so many thermal spray companies continue to produce bad thermal spray coatings? This question is almost akin to someone saying that you make money in the stock market by buying low and selling high; now that is simple and yet everyday even the most savvy of investors loses money off and on ( some more often than others ) in stocks.

Well, at least the thermal spray coatings business is not nearly as hazy as Wall Street. So there is some hope for quantifying and reasoning out the solutions to this burning issue of poor thermal spray coatings quality and the controls on variables. That is essentially going to be the discussion in this article. To start off, one needs to list all of the variables that exist in the first place before you can go around trying to put in controls on them. You might be surprised, but many of the variables that are important actually go unnoticed. Just as an example, next time you walk by the cubicle of a fellow plasma spray engineer or walk by a plasma spray operator, catch him off guard and ask him to list all of the variables that he thinks are important. See how many one can list quickly when caught by surprise. You will be amazed to say the least.

Now granted some parameters are more important than others and need stricter controls than others. But that is not the point. In order to accurately reproduce high quality on thermal sprayed coatings, one needs to identify all of the variables that affect the process, list the importance of each variable and then institute controls on them. New variables that were hitherto not considered may pop up from time to time and in that case they need to be included in the list to be controlled. Now this may seem like a task to be delegated to the R and D department only or to the engineering manager only. That is simply not the case. Everyone in the team from the engineering guy to the operator to the metallurgical lab person needs to work in unison to exert these controls so repeatable coating quality is ensured.

Talk about variables. You will be surprised but years ago when a company I was working in was audited by a quality auditor from a large “independent” entity, he actually made an “observation” ( an observation for those not in quality circles is not a finding and therefore does not require a corrective action report ), that the coatings stripping operation called for rinsing the parts in water. His observation said that there was no specification of the temperature of the rinse water. Room temperature water was not sufficient. His point was that we should have stated that the parts must be rinsed in water that is between fifty degrees to ninety degrees F. Be specific and accurate he said. He was an old man and I was a young engineer and needless to say I took offense to his observation. But now that I am getting older, I tend to think he was trying to teach me the value of specificity in producing repeatable results.

Everything that is a variable that is to be controlled must be specified with upper and lower control limits. What is the high end acceptable point and what is the low end acceptable point, be it temperature, rpm, feed rate, gun voltage or whatever. This is also applicable to set up data such as stand off distance, air jet intersect distance, gun override past part, etc, etc. The operator who does the set up of the plasma jobs needs to be a conscientious person who cares about strict adherence to the controls that are set up and provide feed back to the parameter and tech sheet writer if some controls are too difficult to achieve or some controls need to be tightened up. This level of interaction between people is needed. That is how the great coating houses get to be what they are. Are you one of them?

Plasma coating falling off

2009-03-29T11:59:00.000-07:00

Years ago, I was asked by the newly recruited plasma coating sales engineer at the plasma coating company I was working at to accompany him to visit a customer. I asked the salesman some details about this potential client and very enthusiastically he told me that this potential customer sends out a lot of plasma coatings work to several of our competitors and has been doing so for a number of years. I told him I had never heard of this customer and that the previous plasma coating salesman never even called on this account. To which he proudly replied, “Wonder why he is not here anymore?”. To which I said, “Okay, Mr. Plasma Coating super salesman, I get the point, now let us go and get this customer to our side”.

We started driving towards this customer who was actually located just about three hours away from our shop. Now, note that within a fifty mile radius of where we were, there were close to five plasma coating companies. And so the customer had a variety of plasma coating vendors to choose from. Not so good for us, but good for him. And it so happens that all of these so called plasma coating competitors of ours in this radial area were all low cost producers but at the same time low quality houses. We were not the lowest in price but we were certainly the highest in quality. And so I asked my plasma coating “buddy” now, as to what was the problem with this customer and why did he not consider us. To which he again made a wise crack: “That’s why you are here with me ”.

Okay so after a few stops at a few coffee shops along the way and after stuffing a few donuts, we met with the purchasing manager. He was a middle aged man with greying hair and his belly looked like it had seen several donuts each day. And without too much of introductions and too much of foreplay ( you know how us engineers are ), I asked him point blank what his experiences were with some of the other plasma coating vendors. And he opened up and said the following:

“Well the first shop was cheap, but it took us for ever to get the parts coated and turned around. We would regularly get parts weeks and weeks past the quoted time and it simply got aggravating and I decided to switch sources.”

“And the second plasma coating company, that was a joke too. We received parts with coating in no coat areas on probably ten percent of the parts. And this was a regular occurance. And we would have to reject the parts and send them back for strip and recoat every single time. I got tired of it after a year and decided to switch again.”

“The third plasma coating company was cheaper than the first two and I said to myself I simply cannot go wrong. Just look at their prices. And that was the worst thing I did. Now, I am no plasma coating expert but when my inspector came to me and said ‘Bill, what are you doing, the plasma coating is falling off these parts. I cannot accept them.’ I in turn called the company and said to my vendor ‘ What are you doing, the plasma coating is falling off’. He said, ‘Did you inspect with a 10X magnifier?’ I lost my cool and told him,’My eyes are better than a 10X magnifier, I know a plasma coating when it is on the part and I know when a plasma coating is not on the part. And I tell you your plasma coating is falling off.’”

All I said was “Bill, you will never have any of those problems with us. Just pay our price. You are paying for quality and you are paying to prevent yourself from getting a heart attack.”

And we won the contract!

Thermal spray hvof jobs

2009-02-13T12:09:00.000-08:00

The thermal spray high velocity oxy fuel process is being used increasingly in a wide variety of applications nowadays with the result that there has been a high demand for engineers in the thermal spray hvof jobs market. That is until recently, with the global downturn in the economy. This shrinking of manufacturing globally has resulted in many thermal spray engineers looking for jobs. If you are in the market looking for thermal spray hvof jobs, then there are some things that may be working in your favor and some against. In order to keep your thermal spray hvof jobs search focused and targeted, there are a few things that you could do in order to be successful.

First of all, the hvof process involves knowledge of a wide variety of disciplines in order to be really well versed in it. That is an aspect that can work in your favor, if you have been diligent and conscientious in your previous employment. If you have been goofing off, you are going to be in trouble. You need to be able to rattle off parameters such as gas flows, thermal spray powder feed rates and stand off distances off the top of your mind and be sure that your resume reflects this in depth practical knowledge.

Second of all, know your applications. Thermal spray hvof applications are very specific indeed and if you are well aware of the applications where an hvof coating is the preferred choice over a plasma coating then you can bring that expertise to the new employer and you are more likely to get the hvof job that you are seeking. Conjoined to this aspect is the ability to develop a reasonable level of sales and marketing skills. Even though you may be looking for a thermal spray hvof engineer position, companies like to hire people that can somehow develop additional sales and marketing levels even though that is not their primary job description.

Third of all, know your thermal spray hvof specifications. Requirements of hardness levels, metallurgical microstructures, oxide levels, porosity levels, bond strength levels and such should be in the back of your memory and should be retrievable on the fly. How would you look at an hvof engineer that has no retained memory of these thermal spray specifications as opposed to one that can rattle these numbers off in an instant without having to dig through piles and piles of specifications?

Finally, bring forth your experience on hvof masking to the table. Make sure your resume reflects in-depth knowledge of masking techniques involved in thermal spray hvof processing. Masking for hvof can get to be quite complicated in some hvof jobs and companies are always looking for creative engineers that can come up with simple but effective hvof masking methods. This is a big asset for employers from a practical stand-point and in order to quickly land yourself a well paying thermal spray hvof job, you need to concentrate on all these four aspects.

Thermal spray engineer jobs

2009-02-10T12:47:00.000-08:00

In the global downturn in the economy, every sector has been getting affected and the thermal spray coatings industry has not been immune either. Thermal spray coatings companies that have been primarily focused on aerospace thermal spray coatings have not been nearly as much affected as thermal spray companies involved in automotive applications. Thermal spray engineer jobs therefore have become scarcer in recent times not because of anything inherently flawed but simply because of the lowered demand for all components including those that have thermal spray coatings added on to them. Companies that have concentrated on automotive oxygen sensors and catalytic converter thermal spray coatings have been feeling the pinch quite a bit with the result that many have downsized and eliminated quite a few thermal spray engineer jobs at their facilities. So how do you protect thermal spray engineer jobs at your thermal spray plant and conversely, if you are an engineer looking for a thermal spray engineer position, where do you turn and how do you succeed in your search?

First of all, if you are a thermal spray business owner, the last thing you should do is to lay off your thermal spray engineers and operators at this time. That is the absolute last resort. If your company is running profitably, then let it run as is without comparing to previous year profit levels. A majority of companies are showing lower profit levels anyway and there is no need to put more people on the streets. If on the other hand, you are beginning to bleed in terms of cash flow, then the best starting point is to ask ALL of your employees to take a cut in pay, reduce their working hours, reduce working days, operate a job rotation and such creative techniques to keep people employed at lower wage levels rather than putting them on the unemployment lines. That in my opinion is the sacrifice that business owners can do at times of severe recessions. Next, offer thermal spray engineers positions other than strictly engineering in your plant. For example, they can start performing sales or customer service functions or even direct thermal spray coating functions. Thus, finding alternative positions is preferred.

If you are on the other side of the fence, looking to find a thermal spray engineering position, in this economy, you are going to find it a little bit challenging. That is the truth and there is no two ways about it. However, finding a thermal spray engineer job is not impossible. That word – impossible – should be taken out of your vernacular. There are some adjustments you will need to make. First of all, in order to find a reasonable thermal spray engineer job, the cardinal requirement is that you need to be able to relocate. By relocating ability, I mean you need to be willing to move anywhere. And by anywhere, I mean even to a different country. We are in a global economy now and in a global environment, you might find a thermal spray engineer position in Coimbatore, India or one in Cincinnati, Ohio and you need to take on either one if one is available.

It is important to note that it is preferable to continue in the same line of work rather than start flipping hamburgers until the recession storm has passed, because when the good times return, employers are going to be looking seriously as to how well you marketed yourself in tough times. Outsourcing has become a phenomenon everywhere, and instead of complaining about something that you have no control over, you might as well be willing to go to the source where the thermal spray engineer jobs are available. Additionally, it might prove to be a fun trip after all and you might end up learning about other cultures and countries.

We will address more about finding thermal spray employment in a little bit of a greater detail in the immediate future.

Thermal spray internal specifications

2009-01-11T04:57:00.000-08:00

While thermal spray coatings find applications in a variety of industries including pulp and paper, printing, pump and valve, infrastructure applications, medical and aerospace, we will limit ourselves in this post to thermal spray coatings for aerospace applications. Companies that deal with applications of thermal spray coatings for aerospace applications are generally required to meet customer supplied specifications and have to certify that the hardware that has been coated meets the necessary thermal spray specifications that have been put forth by the aerospace customer which generally leads back to the OEM. While meeting the OEM aerospace thermal spray coatings specifications is sufficient to ship hardware and thus maintain your good quality standing, some companies tend to develop internal standards and internal specifications that EXCEED the OEM specs. Now, what is the point in working harder than needed, one might ask. After all, the payment for the thermal spray coatings service is going to be the same whether the specification was simply met or exceeded. That is exactly what differentiates between being simply a thermal spray coatings house and being a great thermal spray coatings house.

Greatness in any field requires work that far exceeds the minimum required to accomplish the task. A great chef may take additional effort in garnishing the foods that has been cooked. He or she may take extra pains to make sure that the food is presented nicely to the hungry guests. A great comedian may spend a lot of time in fine tuning his pitch and make sure that the delivery is just perfect. The same is applicable to the controls of thermal spray coatings. Internal standards should be developed that exceed the customer supplied specifications. For example, a certain aerospace specification for plasma sprayed T-800 could ask for a minimum R15N of 83. Develop internal standards that require a minimum of 85. Or a certain specification could require that the porosity level be less than 15 percent. Develop internal standards that require the porosity level to be less than ten percent. Now, simply developing an internal standard by writing up a document does not mean anything. It is essential that you develop the proper spray parameters to be able to accomplish the same every single time. This requires tremendous engineering and process optimization and sometimes even ingenuity when the specifications have high standards to begin with. For example, accomplishing a tighter than commonly acceptable levels of oxides in the cleanest HVOF T-800 coating, may require that you purchase powders with much tighter sieve size control than what the powder specification calls for. Or in another instance, you may need to change the position of the gun cooling water entry point and so on. Hence engineering and processing effort will have to be put forth to accomplish the tighter internal standard.

The internal standards tightening does not need to stop simply with raising the bar on metallurgical characteristics of the coating. You could tighten up thermal spray operator qualification standards, booth release standards, powder control standards and so on. By doing so and ensuring that you meet your internal tighter standards every time, you are assured never to have a quality issue meeting the OEM quality standards. But of course, the bottom line of every business is profitability and how does developing internal standards generate greater profitability and improve the bottom line of the thermal spray business. Very easily. By avoiding quality problems, your quality rating with the aerospace OEM goes up and vendors with higher quality ratings are generally given preference over vendors with lower quality ratings when it comes to awarding contracts. This means more sales, more revenue and therefore more profits. Additionally, with high quality levels designed into processing, re-work is greatly reduced and the cost of quality goes down which leads to increased profits. But it is the third factor that interests me the most. And that is, once you have developed tighter internal standards for the particular OEM specification and have confirmed beyond doubt that you can reproduce it every single time, approach the OEM to tighten up their specifications to your internal standards. Aerospace companies are always interested in higher quality hardware and processing and if they take up on your request and do tighten up the specifications, then all of your competitors that were satisfied with simply meeting the old specifications will not be able to step up and meet the higher standards put forth. This means that all their work will start flowing towards your company, which means more sales, profits and improved bottom line. See, one way or the other the bean counters and accounting always get their way!

Thermal spray strategic planning

2008-12-27T07:09:00.000-08:00

Years ago, as I was working as a young engineer in a premium thermal spray coatings facility, a phenomenal event took place. The company had just hired a new Vice President in charge of sales, who had come to the industry from a non thermal spray job shop background. Until that point, such a position did not exist and this was a newly created position. Of course, there were a couple of thermal spray salesmen who called on our customers and were basically ridiculed in the shop floor as simply order takers. The company had several aerospace plasma coating approvals and so the work simply came in as a result of those. Then again, the time frame was over twenty years ago. Within the first four months of getting into his newfound position, this Vice President decided to hold a two day offsite meeting in a beautiful hotel by the sea shore in northeastern United States entitled thermal spray strategic planning summit. And little me, I was invited too. Being young and lacking experience in such things, I thought this is going to be a party that I will never forget and I was ready for the good times.

We reached the quaint hotel that was just fabulous and the meeting started at nine O clock in the morning. We were given the schedule for the discussions and after a very brief introduction, we started discussing department by department, ways and means to speed up the processing with the goal of reducing the lead time for deliveries. Everyone was given the absolute freedom to speak their minds and there was a notes taker. At the end of this session, action items were delegated to the appropriate department heads. Next we discussed material by material ways and means to cut down on costs and consumption. This included everything from paper purchased for the front office to thermal spray masking tape to thermal spray powders to gun nozzles and so on. At the end of this discussion, action items were assigned to those that were key to this step starting with the purchasing agent. We then discussed the sales effort. This was a very long session, wherein we discussed who our current customers were, what markets they served, what other markets that we could get into, who could be our customers in the new markets, how we could target these new customers, who would be the point of contact and so on and needless to say most of the action items in this section fell upon the “old order takers”. Boy they would have to get used to wearing the new cap that this Vice President just bought them We did not even realize that lunch time had already come and gone and the sandwiches that we had eaten already got digested. The final session for the day was to deal with pricing and quotations. We reviewed our pricing structure and method used to price thermal spray jobs and quote deliveries and the new pricing that could be in place if all of the action items such as cost control and expedited processing and such could be implemented.

It was already seven p.m. and we broke off from the meeting and went to dinner. We were served the greatest sea food I had eaten and the greatest wines and drinks were served. The next morning came in and we started off again at seven in the morning with the sun that had barely started its daily run. We discussed all of the action items from the previous day and each of the participants were asked to sign off on the action item given to him or her. And the Vice President had carefully chosen the participants, so no one was left without an action item or two in their hands. We then listened to a one and a half hour speech by him that gave us a crash course on strategic planning and action implementation, goal setting, time consciousness and the power of selling through the use of positive mental attitude. All this was foreign to engineers like me at that point, who were trained simply to engineer goods and not worry about selling them. At the end of the meeting, we were thoroughly exhausted but thoroughly excited at the same time.

Let me tell you, that was the best course in strategic planning that I ever attended in my life. It had to with everything that was practical. Not some old geek professor that kept yapping without ever having been in a real thermal spray shop, not having ever dealt with customers that sometimes do not pay their bills on time and never having ever sold a thermal spray coatings application to anyone. This was real world stuff discussed away from the real world of our actual coatings shop. The phones were not ringing and the guns were not screaming, but guess what; our goal when we came back was to enable the phones to ring non stop and the guns to scream non stop. So the next time you get a chance, set up a strategic planning meeting for your thermal spray company and if done properly, the results will far exceed anyone’s expectations.

Thermalspray part count dilemma

2008-11-13T12:19:00.000-08:00

This article is directed towards thermal spray companies that use travelers in their operations and have operator sign off for each operation performed. Generally thermal spray shops that deal with aerospace or medical hardware definitely use an operator sign off traveler. There are other examples also of quality minded companies in the thermal spray business that use such operator sign off after each operation. As you may know, with an operator sign off traveler, at the end of each operation performed in the entire chain of operations that form the completion of the contracted thermal spray task, the operator responsible for the specific operation is required to sign off along with the part count at the end of his or her specific operation. From a thermal spray quality standpoint, this tells the “world” that the specific signed off operation was performed by the operator in accordance with the written instructions and that the operation was performed on the number of pieces denoted by the operator. While there are other permutations that are possible, in the current treatise we will limit ourselves to discrepancies dealing only with part counts.

An easy way to understand potential problems is by taking a set of practical real world examples. Let us assume that you are in the aerospace thermal spray industry and you have written, approved operation sheets for all of the thermal spray jobs that you receive and process. Let us assume also that a new order arrived. The incoming inspector inspects that parts and signs off stating that he received twenty three parts and logs their dimensions and finds no damage of any kind. The parts then move to cleaning and de greasing. The operator at the cleaning station cleans the parts and signs off stating that twenty three parts got cleaned and then the masking operator signs off twenty three parts received proper masking. So far, things are working perfectly. Next when the parts get to grit blasting, the grit blast operator does his operation then signs off stating he accepts twenty two parts, but incorrectly processed one piece that he tags and sets aside to return to material review board. The plasma spray operator who is next in line signs off twenty two parts and thence to final inspection and then the quality control personnel sign off the certification and the customer gets twenty two parts with a rejected piece that needs to be dispositioned since the error occurred at the grit blast step. While no one wants to make bad parts, a genuine error can occur and as long as the quality checks were properly followed as in our example above, everything is fine.

Now, take the same example above, but let us add a twist to it. Let us introduce an additional operation between plasma spray and final inspection. Let us do a fluorescent penetrant testing for cracks after plasma spray. Now the twenty two parts that were signed off by the plasma spray operator, goes to the FPI operator, who signs off twenty one parts ( due to incorrect part count ) and then the final inspector signs off twenty two parts because he does physically count twenty two parts. Now we have a serious problem. Even though the final inspector is correct as far as part count, there is no guarantee that the FPI operator really tested all twenty two parts and erroneously signed off as twentyone. May be he tested twenty two, one was rejected, but he “forgot” to send it to MRB and let it float along with the other good parts, or may be that there were really only twentyone parts when he received from the plasma person who later discovered that there is an extra part in his booth and then rushed it to final inspect instead of taking it to FPI and upon finding a bin full of parts waiting at final inspect, he decided to put his part also in the same bin along with the rest of the pieces. This is a serious quality problem that has developed now. If I was the customer, I have no guarantee now of the integrity of the operator sign offs. Hence this is a dilemma that needs to get addressed immediately.

Here is a solution to this problem. The quality control procedures must be altered to address these situations as follows: If an operator finds that his part count at his operation, after adjusting for MRBs, rejects, etc, does not match the previous operation’s part count, then the part cannot move to the subsequent operation until the issue of part counts is resolved. This means that if you properly process all the parts that you physically received and no rejects took place and you find that your part count does not match the part count from the previous operation then you cannot sign off your operation, until the issue of the part count discrepancy from two successive operations has been resolved. In the example case above, when the FPI operation accounted for twenty one parts instead of the twenty two that the plasma spray operation accounted for, then the train should have been stopped, the situation analyzed and only then should the FPI operation been signed off and the parts moved over to final inspection.

Seems like a trivial point, but as Michael Angelo said, “trifles make perfection, but perfection is no trifle.”

Obama and thermal spray

2008-11-06T12:57:00.000-08:00

Well, it is final now that Mr. Obama will become the new President of the United States of America What an achievement that has been You might wonder what does this have to do with thermal spray coatings. Well, quite a bit, I might say. First of all, I reflected quite a bit this morning as I listened to news from various sources such as the newspaper, radio and the internet and decided to write this post to deal with what could be the reaction from the thermal spray world. Besides the usual and overly discussed issues of how much taxes will you end up paying, whether you are an entry level thermal spray operator earning a lower income level or you are the thermal spray business owner earning more than a quarter million dollars a year, there are other things that come to my mind considering the results of the new election.

First of all, I consider the enormous up hill battles that Mr. Obama had to face when campaigning for the highest political office in the country. There was the issue of racial considerations and then there was the issue of overcoming the massive competition from Mrs. Hillary Clinton and then there were the million other potholes along the way such as the Acorn issue, the immigration issue of one of his relatives and the statements about the increase in taxes for the wealthy and so on. And yet, undaunted and with a firm belief in himself, Mr. Obama not only won the nomination of the Democratic Party, but also proceeded to win the election. Now, what this teaches us is to keep focused on the goal and keep persevering constantly all of the time and everything is possible. I particularly liked the acceptance speech wherein he says that you need to believe that “You Can”. How often have you come across situations in your own thermal spray coatings world, wherein a microstructure is not up to the customer’s specifications or that the hardness is below the minimum required and such, and you simply want to shut down the thermal spray booth and go home? When such a situation arises again in the future, remember not to give up and quit but to keep trying and you could succeed quite well. Or how about the situation when your potential customer is not easily willing to award you the thermal spray contract and you wish your competitor was simply non-existent. Re-quote the job, improve the delivery lead time, guarantee the quality – do something to win the contract, but do not give up.

You know, history was made in the United States of America on the fourth of November, 2008. Mr. Obama became the first African-American to be elected President. And Jack Welch, the former chief executive officer of the General Electric Company said that Mr. Obama exhibited all the characteristics of the perfect manager. And therefore, taking from his example, everyone in the thermal spray industry, be it the thermal spray operator, salesman, business owner or simply the one in the customer service department taking phone calls from angry customers who want to know when their thermal spray coated parts will get delivered, everyone should strive to achieve the goals set forth by the organization.

And if you have not been setting goals, time to start setting them now. I used to have a T-shirt once that said “No goals no glory”. If Mr.Obama had not set his mind on the office of the Presidency, he could not have enjoyed the moment of glory at the announcement of the results!

Thermal Spray Operation Sheets

2008-11-02T09:54:00.000-08:00

Most thermal spray coatings facilities generate operation sheets to provide instructions for thermal spray masking, plasma and HVOF operators, deburring, inspection criteria and such. These operation sheets that range from simple one page write-ups to very elaborate ones for complex aerospace geometries form the basis for continued reproducible thermal spray processing for the same part when it is received repeatedly as well as forming the basis for a history of how a specific part was processed, should questions arise in the future regarding thermal spray coating quality. Now, one of the biggest complaints that I have heard from thermal spray process engineering teams is that their operation sheets that they have spent hours and hours developing are never read by the operators. I am sure that makes them feel bad. On a lighter note, it is like producing a movie that no one wants to see. On a serious note, this is a problem that many thermal spray shops everywhere face. And put simply, how do you ensure that operators READ the thermal spray operation sheets when performing their tasks? This post is geared towards addressing this very issue.

Operators not reading the process sheets is actually a pretty serious issue and it is the thermal spray quality department who needs to be actively involved in solving it. First of all, there are two basic kinds of operation sheets that can be developed and frankly, I have seen both of them used in service and both seem to have failed to force reading of these sheets. The first kind is the elaborate instruction sheet. Such operation sheets describe in detail, every single step, including basic safety data, precautions, quality requirements, specification requirements and such. These sheets end up running twenty to twenty five pages long for EVERY single part. The second kind is the succinct operation sheets that refer to sets of standard operating procedures as much as possible to reduce redundant instructions. These SOPs, as the standard operating procedures are usually nicknamed, are usually separately maintained and kept outside the realm of the mainstream operation sheet and the operator is asked to refer to these SOPs if he or she has standard questions pertaining to that operation. For example, there might be a SOP designated for grit blasting processing, that will entail how to mix or blend two different grit sizes, how often to use a grit media before changing, how to measure surface roughness after grit blast and so on. Then the main operation sheet will simply specify grit size or blend, pressure and stand off distance together with angle of grit blast.

In either case, if the operator does not read the instructions and goes by “experience” or “gut feeling”, part quality may get seriously affected. Now, the first thing that the quality department needs to do is to insist that operators read the sheets, by conducting operator training. I know, you are probably saying to yourself, that is like asking your kid to not eat candy But that is the first step. The second step is that each traveler that the operator signs off, must have a sign off area for EACH OPERATION, indicating that the corresponding instruction has been read by the operator. This forces the operator to state in a legal manner that he or she DID read the instructions. Signing off on a traveler is a legal act and operators generally do not want to do anything that violates law. The quality department also needs to impress upon the operators that if they sign off stating that they read the instructions and then the part gets processed incorrectly, then they are now liable for having committed two errors and not one and the appropriate actions need to be taken firmly and decisively.

After all, what is the point in writing all of these instructions if no one is going to read them?

Thermal Spray Credit

2008-10-19T10:46:00.000-07:00

As I sit in front of the television set for hours at a stretch, every day for the past month or so, watching the business news full of loom and doom in the financial markets, my stomach begins to turn as I watch the drama unfold developed by greedy investment bankers that discounted common sense lending practices and in some cases threw basic business ethics out the window. The credit crunch that is gripping the whole world currently cannot be taken lightly by anyone, especially people owning and running businesses. The thermal spray industry is not immune to what is happening in the worldwide financial markets; especially the small thermal spray coatings businessman who may not have had too much of cushion to begin with. As everyone knows, unlike an online business, the thermal spray coatings industry is a heavily capital intensive with lots of capital tied up in equipment, spare parts and raw materials that are not inexpensive by any stretch of the imagination. Just check the last payable check to your thermal spray powder vendor and you may want to immediately get yourself a glass of water to calm down! It is no surprise that thermal spray companies that have been relying on short term loans to meet payroll requirements are going to see the effects of the credit crunch faster than those that have not employed such practices and this does put a tremendous strain on the former. As such, as I continue to watch the financial markets beginning to affect more and more businesses, I decided to step back and wonder what, if anything, that the thermal spray industry can do for itself. That is the basis of this post.

Sure, we have thermal spray industry associations in several countries and even global organizations that claim to be of value to its members. But besides holding seminars and conferences, which provide a forum for the exchange of technical ideas and thermal spray industry news and assist in the increase of sales by way of shows and exhibitions, I believe a tremendous value can be provided to its members by establishing a member supported thermal spray credit line. This would be similar to the International Monetary Fund and such similar organizations. The members of the association would all contribute money that would be held by the association trust and be made available at a reasonable rate of interest to those companies that need it. After all, the best help that an association can offer its members is to provide badly needed finances when the member entity is in dire need rather than let that company fail and go bankrupt. Similar to life insurance, this would form a sort of financial insurance for member companies, for which they all pay a premium. The industry as a whole succeeds and survives when each one takes care of the other rather than not. If my neighbor’s house is burning, I will jump to help him at this dire need, rather than let him lose everything even though I may not have been too fond of him at normal times. Now, I understand that member companies may also be competitors and one may not be too eager to help a competitor. But just like drawing money from the IMF is the last resort that a country takes because of the social stigma associated with such an act, I believe, member thermal spray companies will use such a reserve only in extreme conditions.

This step, I believe, will significantly add to the advantages of companies signing up to become members of such thermal spray societies, making membership drives very easy. After all, in this day and age of the internet, quite a lot of things can be learnt without really paying dues to a club, unless otherwise the club or the association brings with it significant financial and business benefits.

Thermal Spray Communications

2008-10-09T14:33:00.000-07:00

In a previous post entitled “A thermal spray mindset”, I had kind of taken you, my esteemed reader, into a philosophical excursion into developing a thermal spray mind set that keeps you focused on the various aspects of thermal spray coatings. As I reflected on it deeper, I found something I observed years ago in a fairly decent sized thermal spray coatings facility that I believe is more apt to be discussed now ( but should have been implemented long long ago ). That is dealing with the building of walls, not just cardboard and plaster walls, but thick concrete walls between the various thermal spray departments, especially thermal spray quality, thermal spray engineering, sales and thermal spray R and D sections. And I am sure this situation still exists in a majority of thermal spray coatings facilities worldwide. And this is not simply a forum to complain, I also have a proposal at the end of this article to address this nasty business practice. The situation goes as follows. The people in the R and D division which may really be a big division or simply an engineer and a technician with one dedicated thermal spray booth lived and worked in their own world. They would attend industry seminars and go to conferences and were supposed to be up to date with the latest and greatest in thermal spray coatings developments. They developed and tweaked parameters and worked on fancy applications and so on. Then there were the thermal spray quality people with their six-sigma charts and other statistical process control data that thought they were the policemen of the thermal spray operators who in their minds were out to sneak through substandard hardware. ( I am not saying that checks and balances are not necessary; that is the reason the legislative, executive and judicial branches of government have independent oversight of each other; but this mind set that I am going to catch you sneaking through a bad part needs to go out the window. ) Then there were the engineering and sales people that had the mindset that they were holier than everyone else and that they were smarter and more in touch with the customer than the other “less brilliant” people in the shop. Of course, how could you discount the production folks, who had the mindset that if they did not put out the hardware day in and day out in the hot and often uncomfortable booths, sweating their armpits off ( LOL ), none of the others would receive a paycheck and that while the others may think they know their stuff, it is the production people that walked the walk and did “ more paw and less jaw” ( a familiar expression from Michigan, USA ).

This nonsensical mind set needs to be changed in EVERY thermal spray coatings facility throughout the world. And guess who can implement this change: you guessed it – the highest levels of management alone can alter this behavior and “tear down the walls” as Mr. Ronald Reagan put it succinctly. A simple move can resolve this problem. Every month, each department is given a turn for a very short period, say half an hour on a Friday afternoon on the third Friday of every month, wherein they can communicate what is new and exciting in their own fields. This is to educate everyone else within the company as to what is going on. For example January the R and D department speaks for half an hour, February engineering speaks; March is quality, April is sales and May is production and back again in June is R and D and so on does the cycle repeat. This will not only enable everyone to stay in touch with the other teams’ findings and achievements but also build better bonding. One thing that has to be clearly specified is that this cannot turn out to be a complaining and rock and stone throwing session aimed at each other; rather a session to update on the new developments and improvements that will hopefully help the thermal spray organization. As in everything else, a little bit can go a long way, just like the longest marathon starts with the first step.

Thermal Spray Rework Limits

2008-10-08T14:06:00.000-07:00

“To err is human and to forgive divine” may be a well known saying, however, this does not sit very well with thermal spray quality control personnel. Not that they do not believe in the age old adage, but that thermal spray quality control personnel want everyone to strive for perfection. They cannot stand thermal spray operators putting on the wrong thickness of coatings or using the incorrect thermal spray powder, coating on the wrong area, incorrect thermal spray masking and so on. As stringent as the thermal spray quality control department may be, there may be a few instances where an error has occurred and the thermal spray coated part needs to be stripped and recoated. There have been some cases where the error has occurred on the same part more than once either for the same or different reason, sending it to the strip and recoat journey all over again. While this does cost quite a bit of money and for that matter, any re-work costs money, there are some limitations and some things to watch out for prior to simply taking the strip and recoat route ESPECIALLY when chemical stripping is used.

It is essential that upon chemical stripping, a laboratory sample travel along side the part that is made of the same base material and has been subjected to the same chemical stripping conditions as the actual hardware being stripped. This includes the same chemical solution, time and temperature in the tank and electrical parameters if electrolytic stripping is utilized. Upon successful stripping, this sample must be evaluated for grain boundary attack and if there is any evidence of grain boundary attack or alpha case formation in titanium alloys, then the hardware is suspect and the customer must be notified for disposition prior to thermal spray. This is particularly important for aerospace hardware. Thus, the strip and recoat option is not without risks and is not a safety net for all thermal spray errors and some alloys may end up with significant metallurgical deterioration depending upon the chemical stripping technique used. Remember nature may not bail out your thermal spray errors like AIG was bailed out

Thermal Spray Succession Planning

2008-10-01T12:44:00.000-07:00

The other day, I was having a discussion with my insurance agent about my automobile insurance policy and he kept harping about business succession planning. I knew Joe always wanted to sell me more insurance but what does that have to do with business succession planning I thought. Being trained in thermal spray, I could not see the connection between insurance and business succession planning and by the way, I thought the meeting was going to be about my automobile insurance and not about business succession planning whatever that may be (LOL). What I learnt that day opened my eyes in terms of what small thermal spray coatings business owners need to think about when it comes to business succession planning. Basically, what Joe hinted upon is that while the larger thermal spray shops may have engineers, salesmen, production personnel and administrators, usually in the smaller shops the owner is the sole heart of the business; more like flying in a single engine plane. When that engine goes, so does the plane. So what happens when the owner of a small mom and pop thermal spray coatings shop dies? The survivor can either sell the business for peanuts or keep it going for a few more years and recover the proper price for the business by selling it later. This latter is what is called business succession planning. And by the way how could Joe, the insurance agent, help an owner with business succession planning not knowing the first word of thermal spray.

Well, the way I understood it is that basically you take what it will take salary wise to hire a top notch thermal spray engineer(s) with sufficient business skills, adjust for some inflation and calculate what it will cost to keep the engineer(s) employed for three to five years. In that time frame, the survivor of the departed can proceed to look for potential buyers of the thermal spray business who will have to pay the proper market value rather than pick up the business for fire sale prices. The survivor may choose to keep the business going and not sell it either, if it continues to make profit and the new hires can be kept employed for the then foreseeable future. The amount of capital that will be needed to finance this transition after the death of the original owner can be obtained by a good life insurance policy taken out by the owner. I then understood where the insurance agent comes in to play in the whole business succession planning scenario. This may sound like too much planning ahead, but consider the following case that has happened in real life right in front of my eyes. Felix was an immigrant in the United States that had come from Peru. After holding several menial jobs, he decided to start a business. It just so happens that he opened up a machine shop as opposed to a thermal spray entity. Being young, he gave his business all the blood, sweat and tears that every small business owner must. I used to outsource a lot of overload work to him. His shop comprised of Felix, an assistant and his wife that kept the books. Everything seemed to go fairly well, until one Monday morning after a three day weekend, I tried to call Felix chasing on some orders. His wife was in tears when she picked up the phone. I felt bad and told her not to take my call that seriously; after all, I was going to just check on the status of some parts and that the world was not coming to an end. She said “Mine did.” And she told me her husband died suddenly of an aneurism. There was no life insurance and she was confused and in disarray. She did not know what to do with the business and it eventually folded up within days. This situation could have been easily prevented had Felix listened to his insurance agent. Guess what I did immediately? I got more life insurance. Of course there is a certain cost to carrying life insurance but the cost of not carrying it when calamity strikes is even more. Entire treatises are now being written on this subject of business succession planning and rightfully so, because why should a business that was built from the ground up after spending lots of money an time simply die with the death of the owner?

A thermal spray mindset

2008-09-18T14:26:00.000-07:00

As I was having a sesame bagel breakfast, I was looking out of the window this mid-morning as the sun was beating down hard and it was hazy, hot and humid; as I gazed at the mighty old oak trees, I thought to myself "the profile of these tree tops is almost like the profile of a thermal spray coating". I am sure many of you have looked at many a photograph of thermal sprayed coatings and how their profiles especially YSZ thermal sprayed coatings look in profile. A glance on to my sesame bagel seemed like porosity and pull out in a badly polished thermal spray coating sample coupon That scene and the thought is what gave me the inspiration to write this post on developing a thermal spray mind set. A true thermal spray engineer needs to have a bond, no pun intended, with thermal spray coatings, thermal spray engineering and flame spray products to the extent that he “sees” thermal spray everywhere he looks. This may sound like words coming from the vocal chords of an ancient Indian sage or a Chinese philosopher, but in all reality, it is the incessant thinking of one’s work that produces great results. I remember years ago, when I was a second year mechanical engineering student and I was persistently reading a book on metal castings and foundry technology during my summer vacation, my mom came up to me and asked me why I was pouring my head into a book on metallurgy and that too during my summer vacation; to that I replied enthusiastically, “I see the beauty of nature when I see these beautiful nodules in grey iron castings pictures” and my mom not being able to feel the depth of what I was saying, simply shook her head and walked away. When you cut grass think of where all thermal spray coatings could be applied in the lawn mower; when you are at an antique tractor show think of thermal spray applications. Think of ways and means to improve the deposit efficiency in your processes at the shop or how you could save money by making a better thermal spray tooling for that pain in the neck high volume job that you won because you low-balled your competitors ( lets face it - you could say you were desperate and desperate times needed desperate measures and so you had to get that order ). If you are a thermal spray quality control manager, think of the status of your operator qualifications, your SPC charting data and the like, whether you are walking around in an air conditioned mall or playing a round of golf in a hot sunny afternoon like today is. If you are a thermal spray expert in a college or university, think of how your research can fulfil the insatiable needs of industry, because believe me the thermal spray industry could certainly use your brains and the years of research that you may have conducted. After all it is this commitment to your task that will take you places you have never been before and let you accomplish things you never dreamt of before.

Time and again, I come across thermal spray engineering people, some of whom have worked at their companies for over ten years and keep staring at the clock to see if it is time to go home to their loved ones. What a pitiful sight that is. Now, there is nothing wrong in having a great family and a group of great friends, but work needs to stay with you as tight as plasma stays in your blood. Whether you are at work or at play, work is as important as your heartbeat. You may go to sleep at night, but that good old heart never rests and quietly beats away. Thermal spray engineering is no different. It needs to become a part of your living psyche. If all you think about is what time of the day you could get the hell out of your workplace, remember those beautiful thermal spray guns and powders and wires are all shedding a tear for not being loved enough. Show them also the love they deserve; after all they are the ones providing you with the income that allows you to take care of your family. Develop a thermal spray mind set and love your field because it loves you dearly.

Thermal Spray Sales Excellence

2008-09-10T13:44:00.000-07:00

In this day and age of increased competition in the thermal spray industry, the tremendous pressure that is exerted on the thermal spray sales departments everywhere can be easily understood. Thermal spray salesmen are constantly asked to bring in more sales and many times they pull their hair apart not knowing where to get the increases demanded of them. And conversely, thermal spray business owners go home with wrinkles on their foreheads wondering how to increase their company’s thermal spray revenues. Obviously, the sales force employed by the thermal spray facility needs to be of the highest caliber. Gone are the days where simply years on the sales force can count for all the credit. Thermal spray sales personnel need to get re-trained on their sales practices and above all their sales mind set. This post addresses this very aspect of the thermal spray business.

Changing and altering the mind set of thermal spray sales people is the one process that will bring in greater results than anything that your company can do. Many sales people assume that simply answering the phones, visiting existing customers and making a few sporadic presentations alone is sufficient; some of them simply become order takers and when the heat is turned up on them they simply try to deflect it by saying that they cannot sell more because either the estimator is giving them high prices or the production function is too slow resulting in late deliveries and such. This finger pointing non sense needs to stop and stop immediately. So what are the characteristics that a thermal spray sales person needs to take a deep look at and modify if necessary in order to achieve thermal spray excellence?

First, set goals for yourself, write them down and evaluate progress made periodically, say once a month. These goals should be targeted and measurable. For example, a goal that says that you will make ten cold calls a week to potential clients is a measurable entity. You could set also a goal that says you will follow through with ten existing customers every month is a measurable goal. After all, what is the point trying to get new customers on board, while losing the existing customer base? Cold calling is difficult and involves time consuming research but the end results could be quite dramatic. Follow-up on previously cold called companies is also important. Sales is a field of repeated persuasion and unless you get your company’s message over and over again to potential buyers, they will simply remain to be potential buyers rather than become your customers.

Secondly, learn more about your own company, its capabilities, its strengths and weaknesses. Your sales pitch to potential customers needs to be well choreographed in advance, whereby you stress the company’s strengths to its fullest extreme and down play the weaknesses as much as possible. Approach your management team with a list of the weaknesses that you perceive and try to minimize and eliminate them if possible. The salesman that interacts more and more with the other departments of the company in a positive and helpful manner is liable to get more co-operation from others than one that simply sits in the front office all day and comes out in to the shop once in a while simply to complain, fret and frown.

Thirdly, develop intimate ties with your existing customers and potential future customers. Try to learn more about the hobbies of your customers, their families and their interests and refer back to data that they have provided about the same. Remember, companies do not place purchase orders; people do. And people have a need to be felt wanted and cared about. The purchasing agent in a large company may have just celebrated his twentieth wedding anniversary or his son’s fifth birthday or his grandson’s birth. Make a note of it and remember to inquire about it in your next call and to send him a card next year. This may sound frivolous, but I myself been on both sides of the table and believe me the salesman that takes a personal interest in one’s life gets subtle preferences over competitors.

Fourth, develop a sense of persistence. Just because you lost a coating contract to your competitor one time does not mean that you have lost this potential customer for ever. As a matter of fact, you need to find out why you lost it and do everything possible to regain it. The very fact that your competitor got it means that this company is spending money on thermal spray services and so you need to be as persistent as ever in trying to win it back for your organization. In this category also comes developing a mind set of desperation. Essentially this means that you need to address every sales call and every sales effort as though your entire life depended on it and not just a paycheck or commission payment. This means trying to remove every obstacle along the way in winning that sale. Note also that the value of the sale has nothing to do with the amount of effort put in. Sure, everyone wants to win the big contracts only. But do not get blind folded to the smaller plasma spray orders; because sometimes these smaller plasma spray orders can grow to become consistent larger contracts.

Finally, develop a sense of trust with your customers. Your customers need to get the feeling that no matter what the problem is, if they contact you then it will get resolved. Their thoughts should equate to feeling that whether it is a quality issue, a delivery problem, an accounting mistake, a pricing problem or whatever else, all that they need to do is to call you and the problem gets addressed. Many purchasing agents nowadays are already overworked and they prefer single point contacts and you need to work towards being that “one call does it all” point of contact. In order for you to successfully accomplish this, you need to be in the good books of everyone in your own company, be it quality, production, accounting, engineering and such.

Sincere and serious effort put forth by you will be recognized in due course of time by your customers as well as your employer and if you are going to be in the sales field you might as well work towards becoming the greatest thermal spray salesman around.

Thermal spray blog layout

2008-09-06T08:56:00.000-07:00

This post is written as a thank you note for all of my regular visitors that have honored me with their visits since the end of last year and as a welcome sign for all the new visitors. As you all may have seen, this blog is dedicated solely to the thermal spray coatings industry and incidentally there are not that many of such plasma spray blogs out there. Hence I hope all you hard core plasma spray engineers have enjoyed this blog thus far and I also hope that visitors that are not familiar with thermal spray coatings have learnt a little bit from my contribution. Of course, every single post is not technical in nature and that is by design. If all that one is interested is in the technical aspect of thermal spray coatings only, then simply read a book. ( No ? ) I try to add a little bit of humor ( humour for all the Britons ! ) and a lot of practicality to my posts. Hence posts may deal with thermal spray production aspects or plasma spray quality aspects, business aspects and sometimes simply the daily routine runs of the average thermal spray operator or flame spray salesman. In progressing to the fourth quarter of this year, I have made some small changes to this thermal spray blog. I have added a navigation help statement at the top to enable readers to see the previous posts if they are interested. This came in response to a visitor ( an ignorant one at that ), that told me that I have a site with only one page! I thought that if this guy was a thermal spray operator, he would fall into the category of those that do not read thermal spray operation sheets completely and simply “wing” it in parts processing and later realize that he missed a lot of steps! Anyway, the navigation help will hopefully help in visiting older posts easily. Additionally, I have finally turned on comments from visitors for new posts. This has been done after a lot of reluctance primarily from the concern of spam comments. I hope this will not be the case this time around and I have opted to moderate all comments and so please be patient as I get around to moderations.

I have also moved around the advertisements on this blog a little bit. I received a note from a non thermal spray visitor to the effect that this seems to be a heavily commercial site. How far away from the truth can that be I thought. First of all, none of my articles thus far have ever endorsed any one company. Second of all, none of my articles thus far have endorsed any specific product. And finally, advertisements that are served by the search engine are not chosen by me and I have no control over what ads get displayed and what do not. Monetizing blogs is a well accepted practice in every field and believe me the little money that someone throws my way by way of these ads while greatly appreciated does not contribute in any big way to my living expenses ( just check the price of a gallon of gas ! ) So for this reader to make all these statements for posts in the past does not make much sense to me. If not here, where else can the reader read fresh posts dealing with the thermal spray world albeit many of them are not extremely technical, but that is the way I chose to write. Anyway so much so for that.

And finally, here is the tip jar. If you have found this site to be of interest, tell your friends and co-workers about it and spread the word. If you have a site, please consider linking here. Thats all. No dollar bills, pesos, pennies, shillings, rupees, yens or roubles needed. Thank you and see you soon again!

Thermal Spray Production Anecdote

2008-09-05T13:18:00.000-07:00

I have written several articles previously about high volume thermal spray coatings applications. Many thermal spray coatings service shops still thrive on the larger size lower volume applications, where they might plasma spray a roller, a dozen impellers or so, plasma coat two dozen printing press rolls or hvof repair a few compressor cases or so. While it is a little difficult to believe, there still exists a sizeable high volume thermal spray coatings applications, wherein you plasma spray or hvof thermal spray thousands of parts every day. Needless to say, in such high volume thermal spray applications, the price per piece would be lower but the overall revenue based on quantity ends up being rather high. It is imperative in such applications to keep close tabs on powder consumption, target and deposit efficiencies and above all thermal spray production rate. It is this last item that I would like to post this story about. We were dealing with a rather high volume thermal spray application wherein thousands of tiny air nozzles had to be thermal sprayed with Metco 73FNS, tungsten carbide coating using plasma spray process. Nothing fancy. The process was all hard tooled with a shadow mask in the front and the gun had a slight up angle of about fifteen degrees. There was a single spindle set up and the coat time was such that the operator could theoretically put out 840 pieces per day. ( Don’t you wish you had that job in your shop ) Coat time was thirty seconds piece to piece. The booth release process took thirty minutes and all operators were given a fifteen minute break time in the morning and one in the afternoon with a mandatory half an hour taken out for lunch from their pay. Kind of a regimented system but one that is fairly common in most factories at least in the U.S. The job was always assigned to this one older operator who was very dedicated after going through a few other operators who weren’t worth a ruck. These other clowns produced 530 pieces and 580 pieces and such and that was no good.

Well, once the ace operator took over, production rate came up to 820 pieces to 850 pieces just like clockwork day after day after day. The big boss had a smile in his face; blood pressure came down and there was a healthy color to his skin tone ( Ha, Ha ). Three weeks into the job, the operator started producing about 950 pieces to 960 pieces per day. This went on for one full week for the entire fourth week. The fifth week, the ace operator production level dropped down back to about 830 pieces per day. This is where the heart to this post is. The big boss called him to his office all upset and told him that he had started slacking off and that he was not minding his station and so on and so forth and demanded ( demanded , I repeat demanded ) and explanation as to why his production level had dropped from about 950 pieces to 830 or so. To which the operator said, “ Well last week, I decided to work right through lunch and break times, just so I could see how much I could produce and what my capabilities were.” Do you think the boss rewarded him?

Thermal spray tensile testing redundancy

2008-09-01T09:13:00.000-07:00

As part of the quality control requirements of thermal sprayed coatings, the adhesive tensile testing procedure is quite extensively used in plasma spray coatings and hvof spray coatings. In the thermal spray tensile testing procedure, tensile bond slugs are to be thermalsprayed using the same parameters as normally used in processing, then glued together with an epoxy which is subsequently cured and then the assembly is pulled apart in a tensile testing machine thus determining the bond strength of the thermal spray coating. It is imperative, obviously, to ensure that the epoxy itself pulls to the specified tensile requirements, otherwise the test results may be suspect. Tensile testing of thermal sprayed coatings is quite an established procedure and is widely used in several aerospace and non-aerospace applications of flame spray coatings quality control aspects. Thermal spray tensile test results in multi layer coatings can give insight into the proper bonding of the base coat to the substrate as well as bonding between base coat and top coat in dual coating systems. By nature, tensile test results for thermal sprayed coatings are highly amenable to statistical charting and hence can provide an additional tool for optimum process control. An added feature of the tensile test procedure which is widely used in releasing powders for plasma and hvof processes which allows for proper raw material control.

What is intriguing is the argument that I have heard over and over again to the effect that “Why should I perform tensile testing routinely in my thermal spray operations, since I cannot even remember the last time I failed such a test when the microstructure was acceptable.” I have also come across situations wherein this argument has gone beyond the argument stage and thermal spray quality control technicians have tended to postpone tensile testing and shipped hardware in the hopes that tensile testing will pass anyway and naive customers have allowed their suppliers to do so by way of providing release forms to allow them ship ahead of test results. Granted, tensile testing cannot be performed as rapidly as other testing procedures, but customers need to account for the added time in their production planning lead time cycles. Shipping hardware pending lab results is something that has never sat well with me for the following reason. Once the hardware is shipped, the customer assembles it in his operations, in a jet engine if it happens to be an aerospace situation, and then subsequent assemblies are carried out and then if the tensile test fails, the suspect hardware will have to be disassembled and replaced with a new component thereby spending more money rather than taking the simple alternative of assembling only after all testing results have proven satisfactory.

Additionally, coming back to the argument of never having failed a tensile test when the metallurgical microstructure has been satisfactory holds weaker grounds. Metallurgical microstructure as far as voids and porosity, oxide stringer levels and the like may be acceptable, but there may have been very bad grit blast contamination at the interface which could lead to poor bonding. What about the situation where the grit blast parameters were correct but the operator touched the grit blasted surface with a rag that is contaminated with oil and other foreign contaminants; that could lead to poor bonding. As mentioned above in multi-layered coatings, the cleanliness between bond coat and top coat is also a factor in proper bonding and this attribute may not be observable in an optical metallurgical mount. Hence, considering these factors, the argument that if the hardness levels and microstructural requirements are met, tensile testing should be waived does not hold credibility in my book. Tensile testing of thermal sprayed coatings is not a redundant test by any means and I certainly do not want to fly in an airplane which has components thermal sprayed by those that validate the arguments in favor of the tensile test redundancy group!

Thermal Spray Gun Maintenance

2008-08-20T14:16:00.000-07:00

The lifeline of your thermal spray coatings facility is needless to say the capital investment in thermal spray coating equipment. It is unbelievable but is true how many thermal spray shop owners pay so little attention to the proper maintenance and care of their thermal spray guns. Many of them operate on a breakdown maintenance schedule where they believe in “If it aint broke, don’t fix it” – that attitude inherently has the hidden implication that “if you try to fix it, you may break it even more”, meaning they have no faith in their thermal spray maintenance personnel or that “if you try to look too hard, you may find other problems that I don’t want to know about ”. In either case, poorly maintained thermal spray guns will end up producing bad coating quality leading to more re-work and unwanted expenditure and in extreme cases can even lead to accidents and injuries. Every thermal spray shop including the very small mom and pop operations must have a thermal spray gun maintenance program in place that they follow meticulously. Developing a written procedure not only documents what needs to be done, but gives an insight into what all could be improved in order to keep thermal spray equipment in good working order so you could have repeatability in thermal spray coating quality. In this article we are dealing only with thermal spray guns. Just changing the nozzles and electrodes when they wear out beyond recognition is no maintenance. Develop a habit ( and a procedure ) to take the gun apart and rebuild it completely, inspecting and replacing parts as necessary every eight hours of operation. If you run the thermal spray booth only two hours a day, ( may be you should replace the salesman and find one that will get more work ), then you can run for four days and then perform gun maintenance; on the other hand if you run your thermal spray booth sixteen hours non-stop, ( make sure your salesman does not quit ), then stop the operation at the end of eight hours and perform a gun change and send the first gun to be re-built. Ensure that nozzles, electrodes, o-rings and seals have been thoroughly inspected and properly re-built. If your maintenance personnel are not very confident, several of the oem equipment manufacturers have classes that they conduct in this regard and it might prove very useful to send your maintenance people to attend these courses. Another key point to note is using replacement components that are not from the oem. I personally do not vouch for non-oem components to be used in your thermal spray systems; sure the look-alike copy from John Doe down the street may look like the genuine original manufacturer’s piece, but what about the chemistry – does the product contain levels of lead beyond acceptability standards – do you know or are you given proper certifications? You know in addition to producing good thermal spray coatings, you are also dealing with liability issues in case there is an accident involving a thermal spray guns in your shop – is the risk worth the saving in using non-oem nozzles and other components? You have to be the judge. In all cases, thermal spray gun maintenance procedures should become an integral part of your operations.

Thermal Spray samples exhibit

2008-08-11T12:46:00.000-07:00

Thermal spray companies sometimes spend a lot of money as part of their flame spray marketing efforts by way of attending thermal spray conference and exhibitions. Many of them have display booths and you know these display booths come at a steep price and need to be utilized to the maximum potential to educate potential plasma spray customers about the capabilities of your thermal spray coatings facility, its engineering talent and so on, in order to get the highest value for the money spent. Many times one can observe plasma spray companies simply put up a big poster, keep a stack of brochures, have a video presentation running in the background, a couple of well dressed personnel manning the booth; all this is fine and well done. And then they have a table with thermal spray coated samples. It is this last feature that this post is all about. The thermal spray samples exhibit is one of the most critical features of your booth. While all the rest of them are simply words and pictures, it is these samples that present a proof of your shop’s real capabilities. Just as a picture is worth a thousand words, an actual sample is worth a thousand pictures. Hence, haphazardly putting together a bunch of samples will do no justice to the visitor, be it a potential customer or simply an on-looker; because sometimes the casual on-looker might turn out to become a customer after all. The determination of what samples get shown and what criteria to use in choosing samples for all practical purposes falls on the shoulders of the thermal spray coatings marketing manager. So what is the ideal method of choosing and exhibiting these samples?

Well, to start off, you need to develop a strategy of what you are planning to stress and what are all the features that you would like to present; additionally, you need to categorize the samples and have some order in what is being shown to the public. In other words, there HAS to be a method to the madness. Here are some thoughts in this regard. To show the range of sizes that you can coat in your plasma spray facility, show a couple of samples of the smallest piece coated, some medium sized pieces and the largest piece coated. And put in descriptions to the same effect besides each piece, even though it might be on a small ticket. Next ensure that you display masking skills and thermal spray tooling engineering skills by showing a couple of intricately masked and coated samples. Thermal spray deburring finesse can be exhibited by showing some nicely deburred parts with may be some holes with a no coat band around them and parts with louevres and such in their characteristics. Next, to show the various process capabilities, display one plasma sprayed sample, one hvof sample, one wire-arc sample with a note adjacent to each. Then if you also have coat and grind capabilities, show an as coated piece and a piece after coat and grind. In order to show excellence in thermal spray parameters development, you might want to show some samples with coatings on internal diameters and steep angle coated pieces. And finally, a little color added to the display table helps the visual senses and so you could put in an put aluminum oxide coated ( Metco 105 NS ) piece, a grey tungsten carbide ( Metco 73FNS ) coated piece, a black ( Metco 130 NS ) piece, a blue ( Metco 101BNS ) piece and a metallic ( Tafa bondarc ) piece and such. If you have the option, I would also include coatings with different surface roughness values as coated, regardless of the process used. An array of industries that your company serves may be of value such as automotive, aerospace, pump and valve, printing, paper and the like along with descriptions for each.

Thus, you can observe that there has to be significant effort put in to the samples area of your thermal spray exhibit. Too often, I hear the same sentences in several facilities to the effect that we are going to have a booth, get me some samples. This kind of poor attention will reflect in the visitors’ reaction who, more often than not, will “click away” from your booth confused.

Thermal Spray Jobs Search

2008-08-09T16:34:00.000-07:00

In continuation with a couple of previous posts, lets say you have located the perfect few thermal spray organizations which interest you based upon your specific field of interest in thermal spraying be it thermal spray research or production coatings and the like, you now need to write a good resume to get you to the interview stage for the thermal spray position and after that, landing that perfect thermal spray coatings job. All of the efforts put forth thus far will not mean anything if these last two steps are carried out incorrectly. As discussed before, thermal spray coatings technology is a great field to build your career; hence you need to pay a little bit of attention to writing a good resume and doing well in the interview that will follow.

Firstly, be honest when you write your resume. Thermal spray employers are not idiots. They can see through fabricated stories and truth stretching statements about plasma coatings clearer than one thinks. Your education credits need to emphasized. Next, if you have had previous thermal spray and plasma coatings experience either during education or at various companies afterward, then state that experience without adding fake claims. I came across the resume of a thermal spray engineer that said that he had designed and built tooling for several jobs at his previous coatings employer “that saved the company two million dollars annually ” The question that came to my mind was, “so this person interacted heavily with the cost accountant of his company ( if they had one ) and verified that the savings were consistent year to year.” So everything after that statement, I simply ignored and discarded. He may have genuinely designed first class thermal spray tooling; but I would have re-worded it as “ designed and built ingenious thermal spray tooling that allowed jobs to be processed faster with less thermal spray powder wastage.” This sounds believable. So, please stay away from ridiculous claims unless you have data to back up and present during an interview in which case say so boldly; for example, “through the use of my tooling, my company saved 15% in thermal spray powder costs – this data provided by our cost accountant will be presented at an interview.” Vague claims of responsibility are transparent and should be avoided. For example, if you had been tasked with coating arc-wire sprayed samples for your professor as part of your duties that he later analyzed for various in-depth metallurgical characteristics, then do not lay claim to the whole research project that may have been carried out over several years and manifold amounts of money depending upon the scope of the project. You are better off simply stating “performed hands-on nickel chrome aluminum yttrium arc-wire coatings samples for organization’s research project.” Remember, believing you are an honest person is an important aspect. I don’t think there is any argument there. Additionally, list your favorite thermal spray articles, your favorite thermal spray authors and the like. Here you have to be careful who you list; for example, try to avoid staunch enemies in the field – this will get you nowhere I have seen people list their favorite sports and recreational activities – that is 1980's style resumes. In today’s competitive world, employers are not really interested to know that you prefer football over golf or vice-versa; they are more interested in what they are getting for the money they are putting out.

During the interview phase, continue with the same character of the resume, namely no overstating abilities or accomplishments – just the truth. However, showing off your true thermal spray knowledge is completely welcome. After all, you want the interviewer to know how knowledgeable you are in your field. What is the point underselling ? If you have truly developed new customers for your company, then bravely state so. Use technical terms rather than service shop slangs and manufacturer part numbers wherever possible. For example, say that “the bond coat should be nickel aluminum” as opposed to “the bond coat should be Metco 450NS”. The person on the other side of the table may not have Metco as his preferred supplier and this may cause problems. Employers like technical people to speak technical tongue and not slangs and jargon. Sometimes, it is preferable that you restate the same number in two different units; for example feed rate in pounds per hour and grams per minute. I strongly recommend carrying a pocket conversation calculator to the interview and pull it out and use it occasionally. It may not mean anything technically, however, that is a powerful sales tactic. Hope this post was helpful in framing thoughts on your thermal spray employment search.

Thermal Spray Networking

2008-08-04T14:26:00.000-07:00

In a previous post, ( you can see it in the Drop Down Menu of All Posts in the sidebar ), we had started discussions on finding thermal spray jobs as in gainful thermal spray employment. We had noted that sufficient research into specific thermal spray coatings interests and subsets need to be made. We also talked about doing research into the thermal spray facility’s business health and management at the thermal spray coatings business. You may have done all this and then located the perfect half a dozen thermal spray coatings organizations one of which you may want to spend the rest of your life ( ? ) with. But who is hiring ? Which thermal spray shop is hiring or which thermal spray researcher is looking for help may be harder to locate. We shall discuss that further here.

Finding thermal spray jobs just like finding other good jobs in other fields is best done by networking with other professionals in the same field. By joining professional organizations such as the International Thermal Spray Association and the like, you come in contact with other thermal spray research engineers and thermal spray business owners with whom you can network and get your name in the market. Additionally, if you have the opportunity to attend thermal spray seminars and exhibitions, there is another opportunity to network. Another method of networking is by reading articles on thermal spray in flame spray and metallizing journals and corresponding with the author. You may have comments, questions and the like and may be some brilliant suggestions and suddenly the author knows about you and he may himself be looking to hire someone or he may recommend you to one of his colleagues. Does networking take time; sure it does but that is a good way to get to know who is really hiring. Sometimes, a research scientist may not have been looking to take on an assistant; but may be after reading your comments about an article he presented or after reviewing a brilliant suggestion that you put forth, he may feel that you could be an asset to his team and he may initiate a hiring request; in this case you started the hiring process yourself. If you plan on networking and you are currently employed, you need to know never to belittle or speak ill of your competitors. You may not like the company that fiercely competes with your current employer and you may not like the fact that they are a thorn on your side, but there is no need to belittle and speak ill of them. Always conduct business in a professional manner and compete on fair and friendly terms. The whole thermal spray industry will take note of your professionalism. I always used to say “Compete based on your strength; not based upon belittling your competitors.” In a future post, we will deal with the thermal spray resume and face to face meeting – what to add and say and what to refrain from and avoid. See you then.

Thermal Spray Jobs

2008-08-03T11:53:00.000-07:00

Recently, I was asked to share my thoughts on thermal spray jobs as in employment in the thermal spray coatings industry. This post is the result of the discussions that went on, with regards to finding or changing thermal spray jobs. In my opinion, the thermal spray coatings business is still in its infancy as far as growth potential is concerned and it is a great time to find gainful thermal spray employment. A few words of advice to the graduating metallurgical engineer wanting to make a career in thermal spay or the current thermal spray professional looking to change thermal spray employers and some notes on thermal spray resumes! First of all, unlike the olden days, the internet is full of resources for finding employment in the thermal spray industry. Simply find the companies performing thermal spray coatings services in the geographical location that you are interested in, go to their web sites and you can instantly send them an e-mail to the appropriate person and discuss your thermal spray interests and there you go! However, while that seems to be the quick way, that may not necessarily be what you want. If you end up accepting employment with a thermal spray company that you have not researched out sufficiently, then you may be back on the market looking to change employers ! Hence, the first step to take is to know what kind of thermal spray field that you would want to get in to. A few thoughts here : are you interested in production thermal spray coating services? If so, then there are several thermal spray coating services shops throughout the landscape that offer flame spray services to various segments of industry. One of these companies could work out for you. As opposed to production thermal spray, your interest may be in thermal spray R and D. In that case, many of the production coatings companies may not be the right choice, even though some of them do perform R&D on a limited scale. You may be better off working closely with a university department that specializes in thermalsprayedcoatings ; and there are quite a few of them around. Then again, designing and building thermal spray equipment may interest you more than services or service R&D in which case, you narrow your search to thermal spray equipment manufacturers. A graduating engineer with significant interest in powder metallurgy can develop a phenomenal career working with thermal spray powders and so should be concentrating on powder manufacturers as opposed to going to work for an equipment manufacturer or coatings service shop that simply uses the thermal spray powder consumables.

Thus knowing what field of thermal spray excites you is the first step to take before spending a lot of time sending out resumes to companies and organizations that may not necessarily serve your engineering interests. Once you identify your primary interest, you need to look further into what subset of that would really interest you. The reason for this is if your interests do not match very closely to what your future potential employer can offer, then you will be dragging your self to work everyday half-heartedly and so will not perform at your best capability and everyone will be able to notice it and then you have wasted tremendous time. Subset interests need to be carefully evaluated also. For example, if you are interested in production thermal spray coatings, if your real interest is in on-site coatings as opposed to aerospace coatings then choose your target company accordingly. Tremendous progress has been made in medical coatings applications and that might be what you are looking for. When it comes to research, the subsets need to be evaluated even more closely. What is the point of joining an organization that specializes in HVOF research, when your interest may be in non-transferred plasma arc coatings. Again, you may be specifically interested in numerical solutions to heat transfer in plasma sprayed coating processes, then you choose your research facility accordingly. Hence knowing your specific field of interest should be the primary focus.

Getting to know your potential employer is the next important step. A little bit of research needs to take place for this. There is no point in wasting time sending out resumes to companies that are on the verge of bankruptcy, unless your interest is in business turnaround of service companies! I remember being approached for employment at one time by a thermal spray coatings company that was trying to be sold because they were losing money. It so happened that that was exactly what I was looking for and with my thermal spray engineering knowledge and sales knowledge and aggressive business nature, I succeeded where others had failed ! If working under constant financial duress is NOT your style, then you need to find more stable companies. See if they have won any big contracts that press releases have been put forth for. If they are publicly traded, see how their stock has been performing. Have there been too many changes in top management. If it is a research establishment, read some of their publications; are they of good quality or are they publishing low grade research. Do they have any patents to their credit. These are some of the things you need to investigate before even proceeding further. In a future post, we will continue this discussion; see you soon !

Thermal Spray Business Slogan

2008-07-27T14:12:00.000-07:00

The biggest challenge that small thermal spray coatings shops face is increasing sales. Medium and larger scale thermal spray coatings facilities that have the luxury of multitudes of oem approvals and massive sales teams have somewhat of a subdued problem when it comes to sales. However, this does not mean that unless the smaller thermal spray shops recruit a sizeable number of sales personnel, they are going to be out of luck. If you are a small thermal spray coatings service shop operator, there are a few things that you could do in a methodical manner from the standpoint of thermal spray marketing and the good news is that you do not need significant capital to invoke these steps. In this post, we will address the issue of developing and publicizing a business slogan for your thermal spray business. What we are talking about is common everywhere in other businesses and you simply need to emulate them. Essentially, your thermal spray business needs to have a slogan that potential customers can remember and sticks to their minds. Many thermal spray shops simply have a name such as abc coatings company or xyz thermal spray limited. That is a good starting point but no one is going to remember that name. For example, as soon as one says king of beers, you think of Budweiser; another example here; what comes to mind when I say we bring good things to life. Of course it is General Electric. The slogan could also nudge customers that have left you to come back to you or customers that know about you but have not dealt with you in recent times. This was the technique that Ford Motor Company used when they came up with the slogan that said “Have you driven a Ford lately”. Think about Wal-Mart – they have a slogan that is simple and powerful, namely “Always the lowest prices. Always”.And yet what is the slogan that is going to make a potential customer think of your abc coatings company or xyz thermal spray limited? Oh well you have a telephone number and a web site. But so does everyone else. So a slogan is almost an imperative.

When developing a slogan, try to be as creative as you can and you could include a key area of your thermal spray processing that might be unique and different from other clowns in the business. For example, if you are the cheapest thermal spray shop around, you could say “XYZ thermal spray limited – lowest prices around always”. If you are a specialist in aerospace coatings, you could have a slogan such as “abc coatings company – specialists in thermal spray ESPECIALLY aerospace”. If you are a quick turnaround organization, how about “In by nine, out by four”. Here are a few other slogans that I would like to suggest. (a) Nobody beats our thermal spray quality (b) Where quality always goes up and price always comes down ( c ) Quality and value for your thermal spray dollars (d) Your thermal spray dollars well spent (e) We treat your parts with love (f) Your friendly thermal spray experts (g) We love thermal spray and it shows (h) The scientific approach to thermal spray (I) Always on time. These are just some suggestions. Obviously, the more creative you are the better the slogan could stick in potential customers minds and that is the goal you are after. And once you have developed a slogan to go with your company name, publicize it and announce to the world; send a letter to all prospective customers and current customers along with a little public relations report. Customers like receiving such notices and announcements; if you do not tell them who will?

Thermal spray cured masking

2008-07-23T16:12:00.000-07:00

In a previous post entitled thermal spray masking tapes, ( you can refer to it from the drop down menu of all posts in the side bar ), we dealt with all the characteristics needed for the proper performance of thermal spray masking tapes. In this post, we will address thermal spray cured masking. As we mentioned in the aforementioned post, thermal spray cured masking can be technically broken down to disposable cured masking and re-useable thermal spray cured masking. Just like thermal spray masking tapes, cured masking needs to be able to withstand both grit blasting and spray coating aggressiveness, needs to be able to be easily applied and easily removed. Obviously, the word easily is figuratively used here. In the disposable cured masking category, the most common is to spray on a liquid masking compound and let it air dry or oven cure at a relatively low temperature. Then the actual masking lines are scribed. This is critical to note because upon curing, if the compound is not conveniently scribbable, ( hey I invented a new word ), then it is of no use. Scribing and trimming sprayed and cured compounds is used frequently in critical masking applications and usually done with a back angle trim to enable smooth feathering and proper cut off requirements. Such masking obviously is disposable because it is removed in the demasking and deburring operations. The other type of cured masking involves making masking shapes by pouring and curing to specific contours outside the part. Such cured masking is quite often re-useable to some extent. Poly tetra fluoro ethylene compounds are frequently used in such cases as well as certain ultra high molecular weight polymers. Buttons, plugs, o-rings and such often fall under cured masking even though technically some of these may simply be purchased complete from outside sources. Of course, masking can be quite extensive from an engineering innovation stand-point and so you need to keep as much proprietary information close to your heart as possible especially from customers to whom specific technical plans and operation sheets have to be submitted for approvals.

Thermal spray masking tapes

2008-07-20T14:57:00.000-07:00

Thermal spray masking is an extremely important step in the overall process of thermal spray coatings application. Thermal spray masking materials can be divided into three basic categories: namely hard masking tooling, thermal spray masking tapes and thirdly cured masking. While the first category is re-usable, the latter two generally fall under disposable masking. There are some cases where cured masking is re-useable in some select thermal spray applications and so technically the last category can be broken down to disposable cured masking and re-useable cured masking. While it may not seem to be so much of a surprise to hardened thermal spray coatings gurus that have been thermal spraying for decades at a time, the newcomer to the process needs to realize that thermal spraying is fairly aggressive for the most part and hence the thermal spray masking materials used need to withstand the level of aggressiveness inherent in the process. Being quite an extensive subject, we will deal in this post only with thermal spray masking tapes and reserve the others for a later time. Thermal spray masking tapes need to have four basic characteristics. The first characteristic is that they should amend themselves to easy application. For example, thermal spray masking tapes must first of all have enough adhesive strength to stick first of all to the bare metal and second of all to itself, since sometimes two or more layers of tape are required and the tape needs to be able to adhere to its own back side. The tape must be sufficiently pliable so it can be contoured on to fairly complicated surfaces that may have bends, curves and such and hence cannot be too rigid. Cleanliness of the part surface does affect how well the adherence of the tape would be to the part, but for the discussion at hand, we are assuming that the surface cleanliness is not an issue. ( I wish that was the case every time, but how many times has part cleanliness been questionable – let the truth come out, hehe ). Secondly, the tape must be able to withstand the aggressiveness of grit blasting. Grit blasting parameters vary quite significantly. Some companies use a standard number sixty aluminum oxide grit, whereas others use a blend of sixty thirty six and so on and on. The masking tape needs to have the ability to withstand the grit blasting process without fraying mechanically and without losing its adhesive strength. Then of course the third characteristic is to be able to withstand the actual thermal spray coating process itself. While masking for standard air plasma spray or twin-wire arc spray is not that difficult, ( relatively speaking of course ), masking for hvof becomes really tricky. ( More on this subject at another time ). There have been many cases where the coating process is so aggressive that there is a layer or two of masking tape on the part followed by hard masking so that the tape is under the wings of the hard tooling. But generally, the tape needs to be able to withstand coating temperatures as well as particle impingement, without fraying or giving way. And the fourth characteristic is that the tape must be removable in the de-masking operation. If the adhesive in the tape is so strong that it takes a super human hero to remove it then be it known that super humans are a rare commodity these days, considering the lack of exercise and high fat diets that most of us are under and so you may have to ship the part to your customer with the masking tape left as is and he is not going to be very pleased.

Thus the engineering requirements on masking tapes is quite demanding and that is why when a new thermal spray masking tape is touted by your friendly salesman, you need to really let it go through proper testing under parameters used in your own shop rather than those recommended elsewhere. And of course there is a fifth characteristic that most engineers do not necessarily come to terms with and cringe even at the mention of it and that is it needs to be economical. Did I mention that engineers do not like the word economical?

Women in Thermal Spray

2008-07-16T13:29:00.000-07:00

Thermal spray coatings services fall into the industrial commercial area of business. For a long time now, thermal spray coatings have found applications in aircraft, pump, paper, printing, textile industries and so on which generally fall under medium to heavy industrial applications. From the early days, even when medium and heavy industries were operated with a male dominated workforce, the thermal spray industry has had significant contributions by women. This is especially true of the thermal spray industry in the United States. In the early years, women in thermal spray companies in the United States could be found busily performing masking operations primarily; this is because a lot of patience is needed in masking large volumes of parts for flame spray applications and women have generally exhibited a high level of patience and finesse in this area. However, in recent years, women have exhibited tremendous excellence in operating metallurgical laboratory evaluations, performing quality control inspections, performing thermal spray engineering functions such as writing process sheets, standard operating procedures, sales functions and so on. In rare plasma coating shops in the United States, I have even seen women flame spray operators. The thermal spray industry, in this regard, is a model for other industries where women have been kind of left behind in being given significant responsibilities.
For some reason, thermal spray shops in other countries are still predominantly covered by men. The women in such companies may perform office and administrative functions but are not very much present in the actual manufacturing areas. I do not know why this division exists which frankly has no basis. Safety really should not be a concern since nowadays all kinds of safety gear is available to thermal spray operators from hearing protection to respiratory care. A lot of women are pursuing both undergraduate and graduate level education in the field of metallurgical engineering and that is a boon in my opinion to their potential involvement with thermal spray coatings. Several women have even started and have been operating profitable thermal spray companies in the United States and my hearty congratulations goes to them. Running a thermal spray business is no easy matter and women have done well so far. I strongly believe that women everywhere in the world should be made a bigger part not only in the thermal spray field but also in other medium to heavy industries, taking the example of the U.S. thermal spray industry model.

Thermalspray inspector eyesight testing

2008-07-12T12:21:00.000-07:00

Thermal spray production facilities invariably have three levels of inspection, namely incoming, inprocess and final. Thermal spray inspection techniques generally fall into two categories namely visual and dimensional. Incoming inspection to check for starting dimensional points and visual inspection for dents and other damage, while seeming to be mundane and not glorious forms the basis for subsequent inspection and processing levels. Inprocess inspection in thermal spray operations usually entails verification of proper masking lines and non-maksing areas as well as proper grit blast surface by way of visual inspection as well as prevention of masking failure. For example by over grit blasting, if the thermal spray masking tape gets deteriorated to the point of getting frazzled, then proper masking is not going to be achieved in subsequent flame spray operations. In process inspection also involves dimensional checks at the thermal spray booth as parts get coated to observe any significant deviations from mean dimensions, as well as visual inspection of coating quality. There are many specialized thermal spray applications with hard coatings such as tungsten carbide-cobalt coated using specialized parameters that produce super hard coatings but are also prone to cracking. In-process inspection using quick fluorescent penetrant methods at the flame spray booth on parts as they come out is critical to ensure that crack propensity is observed and corrected immediately. Then of course final inspection covers almost all aspects of inspection from visual inspection to ensure proper coverage, proper masking lines, proper demasking and deburring of the coated areas, dimensional checks as well as testing for cracks and other defects. While the necessary instrumentation must be made available to the inspectors and all the applicable training provided, the key to this post is the observation I have made in many thermal spray coatings facilities about conducting eyesight testing for quality control inspectors. Again seems rather mundane and non-glorious, but think for a minute. If the inspector who basically accepts hardware, critical hardware sometimes that end up in aircraft engines and medical devices, does not have accurate vision, then how much weight can you put on his inspection report? Was he able to accurately determine crack free surfaces or accurate cut off points on masking criteria? Well, many thermal spray companies require a mandatory physical testing of new hires from a health stand-point that includes eyesight, hearing and respiratory testing but this is mostly performed for liability reasons from a workmen's compensation stand-point rather than from an quality assurance stand-point. What needs to be done ( and by the way this IS done in some thermal spray facilities ) is that past the initial testing, every thermal spray inspector regardless of incoming, in-process or final, should be sent out for eyesight testing every six months and proper eyesight correction procedures must be performed and actually the company should pay for this procedure. If there is a fighting contest as to who will pay, then frankly that shows that quality control is not taken seriously.

Thermal Spray Incoming Inspection Dilemma

2008-07-08T15:06:00.000-07:00

Thermal spray coatings quality control functions obviously involve inspection procedures that include incoming, in-process as well as final inspection. The common thermal spray coatings inspection procedures involve metallurgical lab testing, dimensional testing and visual inspection.Visual inspection in most prominent thermal spray coatings facilites takes place in three distinct locations, namely incoming, inprocess and final. In this post, we will limit ourselves only to incoming visual inspection. Incoming visual inspection comprises of inspecting parts for nicks, dents and other damage to the required thermal spray coating area. For example, knife edge seals that are employed in aircraft engines generally get coated with thermal spray abrasive coating combinations of nickel-aluminum followed by aluminum oxide generally by plasma spray techniques. If the knife edge surfaces configurations come in damaged, then there is no point in thermal spraying the parts. Hence incoming visual inspection plays an important role in ensuring that the parts coming in prior to any thermal spray work being performed on them are okay from a visual standpoint. Note that we are not dealing with any dimensional discrepancies at present. Most quality control manuals and instructions usually spell out the procedure for incoming visual inspection whether surfaces shall be examined with the naked eye or under specified magnifications. However, what most quality control manuals and instructions do not specifically address is what happens if the incoming visual inspection reveals that some area that is NOT a required thermal spray coating required location exhibits characteristics of concern. What is the inspector to do then. Obviously, the answer would be to get his supervisor. Okay. But what does the supervisor or QC manager do then. Obviously, the answer would be to contact the customer and let him make the decision as to what to do. However, that is not the end of all problems. If the inspector finds something potentially troubling with any area of the part prior to thermal spray in the incoming inspection department, obviously he or she is to raise a red flag. But then the burning question becomes how much of his time should he spend looking at areas that he is not required to look. This does not seem like a big deal when dealing with small quantities like a few compressor cases to inspect. But imagine doing a one hundred percent visual incoming inspection on a thousand air nozzles or two thousand compressor blades EVERY day. Now all of a sudden, the question of where does the inspector draw the line of where his responsibilities for inspecting to enable subsequent thermal spray operations ends and where his bigger responsibilities for overall part integrity ends, becomes a subject of great debate. Additionally, where does the QC manager draw the line when specifying this limit of responsibility in his quality control manual which then becomes the guideline to follow by everyone in the organization including the incoming visual inspector. This is especially important for thermal spray shops that deal with aircraft or medical components where part liabilities run very high. From a legal liability stand-point, it now becomes extremely important during auditing of ones quality control manual that this set of instructions be very clearly specified and be customer concurrence be clearly obtained. This will avoid a lot of problems later.

Thermal Spray Coatings thickness testing

2008-06-28T13:09:00.000-07:00

Measurement of thermal spray coatings thickness is as you may know, a critical quality control aspect. However, while this seems to be extremely simple, there sometimes seems to be confusing factors in techniques for thermal spray coatings thickness measurements especially in small production shops. I decided to concentrate on this aspect for this post. There are basically four techniques for performing thermal spray coating thickness measurements. The first method is the use of a flat anvil micrometer. In this case, the flat anvil of the micrometer will give the reading of the peaks of the thermal spray coating. If the component that has been thermalsprayed is to be used as is without subsequent grinding or other finishing operations, then this is the final coating thickness. The same is the case when using a vernier caliper; namely you get the reading of the peaks. The second method is the use of a pin micrometer. In this case, the lowest reading that you obtain is the thickness of the valleys and the highest reading you get is that of the peaks. If the difference between the lowest reading and highest reading is quite significant, then it simply means that the profile of the as coated thermal spray material is quite prominent. This could lead to some problems if the grinding allowance is lower than the difference between the valley readings and the peak readings. Quite simply upon grinding, the thermal spray coating will not clean up sufficiently and this may be cause for rejections. On the other hand, if the difference between the peak values and the valley values is not significant, then it means that the profile is fairly uniform. The third method of measuring thermal spray coatings thickness is by metallographic means whereby you attach a sample tab that is coated alongside the component and preferably bent to match the profile of the part being coated and then a metallurgical mount made of the section and then measured in an optical micrometer. Sometimes, depending upon customer requirements and parts sizes, actual parts themselves are mounted and metallographically evaluated and then valley thicknesses, peak thicknesses and average thicknesses can be reported. A fourth method is to measure coatings thicknesses by electronic gages such as Fisherscope and the like.

Obviously, other methods such as using height gages, etc are not addressed here. An important aspect of quality control is that along with the reporting of the thickness, the method of thermal spray coating thickness measurement MUST be stated in the inspection reports. Many times this aspect is overlooked and can lead to confusions on the part of the customer’s auditor since he is not then privy to this very important piece of information. Another case in point is that when electronic measurement techniques such as Fisherscope, etc are employed, there must be a hard correlation established for every batch between the electronic gage and a mechanical gage. In numerous instances, significant statistical process control charts and analyses are performed on coating thickness variations and control especially in high volume thermal spray; in such cases all of the data is suspect if the measurement techniques are not clearly understood and spelled out.

Low stress thermal spray TBCs

2008-06-20T02:27:00.000-07:00

Thermal barrier coatings applied by thermal spray coating processes find a tremendous level of applications in the aerospace, ground based power generation and other industrial markets as engines and components are required to run hotter and hotter for better efficiency. Plasma sprayed 8% yttria stabilized zirconia and 12% yttria stabilized zirconia are popular choices. Such thermal sprayed TBCs usually have an underlying bond coat of NiCrAly or CoCrAly or CoNiCrAly. However, delamination and spalling of thermal barrier coatings applied by thermal spray processes caused by residual stresses in the coating leads to failure of the thermal barrier property and the coating is rendered useless. Hundreds of studies are conducted, especially by thermal spray research scientists in trying to understand the stress generation mechanism of thermal spray TBCs. Analytical and computational models are used and x-ray diffraction techniques for determining residual stresses in thermal spray coatings are employed to come up with numerical values for the stresses generated. Both operational mechanical stresses developed in a component thermal spray coated with TBCs as well as oxidation stresses developed contribute to potential coating failure. Fatigue cracks in the coating and their propagation rates will also determine the life cycle of the coated component. A major problem that one has to deal with is the fact that unlike testing a virgin machined component, testing a component that has a thermal spray coating, YSZ TBC or not, is that the level of exact duplication of thermal barrier coatings from batch to batch is extremely difficult in thermal spray; I am referring to the exact duplication of porosity levels, porosity distribution, etc., the latter being of more interest to me. Yet the question that arises in the mind of the practical thermal spray coatings operator is that while research in the subject of reducing stresses in thermal barrier coatings is not complete by any means, what can he or she do NOW based upon what is known until today, to at least keep the thermal barrier coating at its lowest stress levels and optimum functionality.

I would say that the first thing to do is to apply the bond coat with the optimum parameters so that it is as clean as possible with as low an oxide content as possible. Obviously, if the only process that you have at your disposal is air plasma spray, then your bond coat cannot meet the cleanliness of LPPS standards. However, there are NiCrAly bond coat parameters for air plasma spray that produce lousy bond coats and there are those that produce much better quality bond coats. So having a clean bond coat is a major step forward in reducing the failure rate of bond coat - thermal barrier systems. Secondly, the time lapse between bond coat application and top coat TBC application should be minimal. I have come across cases where a million parts are all bond coated in one set up and then days later the same million parts get all top coated.( may be days later the same million parts all failed in service prematurely! ) Contamination after bond coat application is a recipe for failure. Thirdly, I would keep the NiCrAly or CoNiCrAly bond coat thickness to the high limit allowable by the specification. If I am a specification writer, then instead of specifying a bond coat thickness of .002 inches to .004 inches or .004 inches to .008 inches, I would specify a bond coat thickness of .006 inches to .012 inches. Finally, top coat thermal barrier coating needs to have the prescribed porosity as allowable by the specification. Making TBCs with minimal porosity is not a good idea. More importantly, porosity distribution needs to be uniform. Non-uniform porosity distribution in TBC top coats contributes to pre-mature coating failure. Every coating batch must be properly metallographically evaluated for uniform porosity distribution with standards set in place. Now, metallographic evaluation of thermal barrier coatings is a topic in itself for another time and we will not deal with it here; it is suffice to say for now that if the metallurgical polishing technique is flawed and pull outs during the polishing process are construed as inherent porosity in the coating, then the evaluation technique will take you nowhere.

Low Pressure Plasma Spray Oxides Control

2008-06-12T14:25:00.000-07:00

The low pressure plasma thermal spray process is amenable to producing the best clean low oxide coatings in the thermal spray coatings family. So much so that while high velocity thermal spray processes try to come very close to LPPS thermal spray process coating quality and imitation may be the best form of admiration, LPPS still is the best choice for producing a high quality oxide free thermal spray coatings. I know this statement is going to create some stir among the hvof thermal spray fans, but lets face it – hvof tries to imitate LPPS quality when it comes to low oxide clean thermal spray coatings; LPPS came first; then came hvof. Such low oxide clean coatings produced by the low pressure plasma spray process find fantastic applications in aerospace turbine shrouds, dental implant coatings and other high tech applications. The key to producing high quality LPPS coatings though is to have an excellent maintenance program in place. Unlike other thermal spray processes, LPPS is a high maintenance “animal”. It is in this regard that the balance of this post is addressed.

Several years ago, I came across a thermal spray operation, where a thick, high quality CoNiCrAlY coating had to be deposited on thousands of parts consistently meeting stringent specifications where very low levels almost negligible amounts of oxides were allowable in the coating and the interface between the coating and the substrate had to be very clean with minimal contamination. Such coatings are usually metallographically evaluated at 200X magnification as well as 500X magnification. The low-pressure plasma spray system used was successfully producing this coating with very high levels of repeatability. Stand off distance was fourteen inches and reverse transfer arc cleaning was used. However, suddenly the coating quality started deteriorating with the oxide levels slowly rising. Obviously, the coating process was stopped and upon maintenance evaluation, air (oxygen) leak up rate was well within limits indicating no leaks; parameters were very carefully monitored and everything looked okay; and yet poor quality coatings were the result. The common sense was that if you are getting too many oxides, oxygen is leaking in to your system. The frustration led to an inch by inch evaluation of every single hose and fitting and guess what was found – the leak was actually coming from a pin hole in an argon hose carrying gas into the powder feeder. When the leak up rates were determined, the powder feeder was a part of the system but the supply lines were not and so argon was leaking out; when the plasma spray system was running, air was getting in to the system through the pin hole in the supply system, causing excessive oxide levels in the coating. Replacement of the argon hose solved the problem of excess oxides in the CoNiCrAlY coating. Seems simple now, but as I always say everything is difficult to understand until it is understood.

Thermal Spray Erosion Testing

2008-06-02T13:34:00.000-07:00

Thermal spray coatings that fall under the abradable coatings family such as nickel-graphite flame sprayed coatings are sometimes required to be tested to obtain an erosion number. This post addresses the concerns regarding the erosion testing of thermal spray abradable coatings from a practical standpoint as would be faced by a typical thermal spray coatings production facility. As one might know, this erosion testing procedure involves testing a standard panel made of Lexan and then testing the actual thermal sprayed coupons coated at the same time as the actual hardware in the same test rig with the same setup. The variables in this testing procedure are way too many to obtain consistent results. While the claim is that normalizing the erosivity number against the lexan sample would eliminate variations in the testing process, the actual depth measurement of either the lexan sample or the actual thermal spray coated coupons themselves may be suspect. The reason I say this is because the erosion pattern in both the lexan sample and the thermal spray sample is a smooth curve and then how do you put a flat anvil micrometer to get the actual depth measurement without deviations. The air pressure that is driving the erosion media may vary albeit in small amounts; sometimes the operator re-uses the media and that may cause variations in the erosion number since there might be foreign particulates in the media. Additionally, one needs to put the thermal spray booth production on hold, until the erosion number is obtained as opposed to coating all parts and then perform the erosion testing after the fact, because what if the erosion number is not in the specified range and you have coated all the parts. I know what the immediate answer is: strip all the parts and re-do the process just like shampooing and rinsing ( repeat the process over and over again ) or blame it on the thermal spray production facility being out of control and so on. The erosion number obtainable from an erosion testing rig as referred to above may be fine for an R and D facility but is cumbersome to say the least to a production thermal spray shop. The erosion testing rig itself is cumbersome to set up quickly and besides the fine powder used in the erosion process flies all over the place even though you may have set it up inside a grit blasting cabinet. I am sure all the readers that have had hands on experience dealing with this headache on a frequent basis agree and those readers that deal with this headache on a sporadic basis take the stand that “if you know what you are doing then it should pose no problem”. To the latter, I say, tell that to the boss who is screaming that the thermal spray booth that is to coat the abradables has been on hold for two hours waiting for the erosion guy to come up with the erosion number!
In my humble opinion, the erosivity testing rigs and erosivity numbers obtained therefrom, need to thrown out of the window and spec out a simple quick method such as using an R15Y number to be met. If an OEM still is interested in the erosion number to be within a specific range for his application, then the burden to obtain the corresponding R15Y number falls on his shoulders and not on the poor lowly thermal spray shop. The R15Y ball is bigger, relatively speaking, and will compensate effectively for the peaks and valleys in the as coated sample and if the hardness testing machine is under calibration, then you wont need no lexan samples. There is a significant correlation between hardness and erosion and while the correlation may not be linear and simple, the simplicity and speed of the test far outweighs the accuracy claim of the erosivity test rig erosion numbers. Then again, many of the abradable coatings used in clearance control applications are not designed for abrasion by blasting media anyways, so why are we playing the silly game of thrusting down a test full of suspect results in place of using a time tested hardness number such as an R15Y value. It is the abrasion of the blades on to the abradable coating that forms the perfect seal groove in these applications with the proper clearance. Tell me where the erosion number, normalized or not, is a better indication of performance as opposed to an R15Y value.

New Thermal Spray Boss Contd

2008-06-01T08:54:00.000-07:00

In continuation with a previous post entitled New Thermal Spray Boss, wherein we talked about how a bad manager did nothing to a bleeding thermal spray company, this company decided to hire me as the manager of the thermal spray division in trouble. Unlike the previous leader, I had significant thermal spray engineering background although I was not an expert in plasma spray technologies by any stretch. The thermal spray field is just too complicated for anyone to lay claim to knowing it all. In this post, I would like to present how I fared in the new thermal spray assignment.

I showed up for work in decent work clothes and I could see the smile in the thermal spray operators faces – they felt I was one of them. I bonded instantly with the personnel. The first day, I met the thermal spray quality control manager and requested a copy of the quality control manual and told him that whatever we do, we shall never compromise on quality. That put his mind at ease; because the fact of the matter is that people in production functions often bang heads with people in the quality function and vice versa and this battle does not help anyone in the long run. What is the point in shipping hardware today and billing it, only to receive it back tomorrow to re-work it? I scrapped the morning meetings for good and that saved us valuable production time. The spray schedule as to what gets coated in what spray booth would have to written up the previous evening, so the thermal spray powder crib attendant can get all the thermal spray powders ready for the operators in the morning on time. The foreman of the shop had to resign (unwillingly) because of an ailing mother that he had to take care of and I told the really really big boss not to replace him and that I would take on that responsibility also. The boss was amazed that he could instantly save on one more salary ( let alone the fact that I was working for nearly half of Mr.Doolittle’s pay ). Later the thermal spray salesman quit to take up an offer that paid him much higher than what he was getting paid then, and once again, I chose not to replace him. What I proceeded to do was to find out exactly how long it took us to process parts – usually it was about three days. I was quoting all parts with a standard turnaround time of five to seven days knowing very well we could do them in three days. Then I would proceed to woo the customers to pay an expedite charge and they could get the parts in three days. Eight times out of ten, the customers wanted the parts quicker so they did not mind paying an extra expedite charge to get the parts two days sooner – that meant instant increases in revenues for us.

I then proceeded to establish a second shift with a skeleton crew borrowed from the main shift. All the set-ups would be performed by the main shift operators and the second shift personnel had to simply keep the plasma spray jobs going forward. This enabled improvement in machine utilization because usually the first shift pays for all the machine payments. We took on some incremental work where the profit margin was marginal but not negative by any means – all of the incremental work got finished in the second shift. We had an outside cleaning service coming in to clean the shop and I stopped that service and told everyone to clean up their own areas. We were on a roll. We started making money like we never thought we could. Thermal spray operators were requested to work overtime everyday and on week ends. They were happy because their paychecks increased. The boss was happy because his profits increased. And everyone was happy Mr.Doolittle was gone!

New Thermal Spray Boss

2008-05-28T14:15:00.000-07:00

I wanted to write in this post about my friend’s experience many years ago in a thermal spray coatings facility which was going through some tough times financially. To be more specific, it was one location of a multi-plant thermal spray coatings service shop that was weak financially; and with his luck, he was working in that location Whether it is thermal spray or anything else, he always seemed to be at the wrong place at the wrong time Everyone from thermal spray operators to thermal spray engineers to customer service people were walking on egg-shells not knowing when the axe would fall on their heads and fridays were always seeming like the axe mysteriously came closer. The really really big boss decided that they needed a change in management ( good move ) and went and hired this new guy with a lot of experience in management but no experience in thermal spray ( not a good move ). Let us give a fictitious name to this new boss; lets call him Mr.Doolittle. So Mr.Doolittle walks into his new job the first day with a fancy suit and tie, jingling the coins in his pocket I was told and I shook my head to myself and told my friend, “this guy aint lasting more than one year” and everyone there thought I was simply being cynical in my outlook. I told them “I never thought much of a man who jingles the coins in his pocket.”

So Mr. Doolittle comes in and the first thing he does is to re-furnish his corner office; put in new curtains, new desk, fancy chair, a new computer with a big screen and then hires a new thermal spray engineer and lays off two thermal spray operators on the floor within a matter of six weeks. Mind you this person had no clue as to what the real problem was why they were losing money. “We need better organization”, he said and apparently implemented a formal meeting every morning that lasted for ever, it seemed like. He went on sales trips that brought in no sales and problem solving trips that solved no problems. Meanwhile, the really really big boss was getting the big expense bills and the fat salary that he was paying Mr.Dolittle. The division apparently continued to lose money and the morale amongst the thermal spray operators and maskers and others kept going down.

Two years later, I guess the really really big boss woke up one morning and decided he was going to fire this Dolittle person, but didn’t have the heart to do so ( bad heart condition ). That day, Mr. Dolittle calls him up on the telephone and tells the big boss that he would like to tend his resignation since he received a new job offer from some other company ( unrelated to the thermal spray industry ). I guess the big boss had a miraculous dream of getting rid of Mr.Dolittle and he didn’t even have to fire him So two years and lots of cash later, Mr.Dolittle was gone, but the division was still not making any money. At least it was losing less money now

The moral of this story is really simple. The manager or leader of a thermal spray shop must be well versed in the thermal spray industry. He or she does not have to be an ace thermal spray operator or a top level coatings scientist, but he needs to have had hands on experience in the business. Management skills alone will not cut it and above all hiring someone with common sense helps too.

Thermal Spray Engineering Outsourcing

2008-05-14T14:32:00.000-07:00

As thermal spray coatings facilities worldwide look for ways and means to control costs and improve their bottom line profitability, outsourcing as an option has crossed the minds of many thermal spray management teams. Some thermal spray facilities are already performing outsourcing in a limited manner – some successfully and some not so well. In this article, we will deal with the issue of outsourcing strictly from a thermal spray coatings engineering perspective. By outsourcing, we do not mean only inter-continental global outsourcing; on the contrary, we term outsourcing to mean also within your own locale as long as it is outside one’s own thermal spray facility. As mentioned, other aspects of thermal spray operations besides engineering are not addressed in this post.

Many thermal spray coatings service shops have to present detailed engineering technical plans for customer approval prior to processing hardware. This function has outsourcing potential. Additionally writing of standard operating procedures and revising them to meet newer specifications and revised specifications is another mundane task that does not need to be dumped on to your own company’s engineering department. Many thermal spray shops have thermal spray safety engineering that also is tasked with maintaining material safety data sheets and writing and updating hazard communication manuals and the like – this can be outsourced. I have also heard of sophisticated robotic programming shells being outsourced. These are not part specific programming; rather, these are shell programs – for example an up-down traverse program or an x-y simulator program to be coded for a specific robot. Such shell programs need to be coded so that there is sufficient thermal spray operator interfacing and input to be operator friendly. Thermal spray tooling design and manufacture for specific high volume coatings contracts can be outsourced very well. On the contrary, I would not recommend outsourcing the writing of specific part operation sheets or the writing of part specific robotic programming. Hence one needs to be careful in choosing what function gets outsourced and what does not.

And what does this all mean to the thermal spray engineer that is worried that his job is going to be gone? It means nothing but signs of prosperity and money coming your way Why do I say that? In every seemingly bad situation, there is always a hidden silver lining. Companies are outsourcing because they do not want that specific task to be within their payroll. Hence, if you are a thermal spray engineer, then you can start your own engineering company offering these very services that are being outsourced. Be competitive in pricing and be superior in quality and the work will simply come to you. You can be very busy and be earning a lot of money by designing good thermal spray tooling, writing standard operating procedures, developing engineering technical plans and so on. In fact, of late, quite a few such small companies have started capitalizing on the motives of companies that want to offload their repeat engineering functions. So turn it to your advantage and everybody will end up winning.

Thermal spray industry under new president

2008-05-07T14:18:00.000-07:00

The thermal spray industry in the United States is still in its adolescent stages of growth. From the early days of wire spray metallizing to twin wire electric arc spray to plasma spray and high velocity processes, the thermal spray industry has made tremendous strides in technological advancements with more and more progress to be made in the coming years. Nano technology spray is just in its infancy and sophisticated controls to fine tune the thermal spray process to minimize the myriads of variables are going to get implemented more and more in the coming years. With all this technology lurking in the horizon, the thermal spray industry can really get a boost or get a massive boot depending upon the posture of the new leadership in the oval office and the congress. This aspect is casually discussed in the thermal spray meetings and conferences without really getting into the details. Depending upon the position that the newly elected president and congress take on the various aspects affecting the growth of the thermal spray industry in the United States, it can also affect the thermal spray industry in other parts of the globe. Remember, there is no such thing as an insulated market anymore; everything is global; what happens in America does affect what happens elsewhere and vice versa.

One thing is certain; there is going to be change since President George Bush has already served two terms in office. If the newly elected officials really tighten up the air quality standards and particulate emissions from thermal spray facilities, for example, some of the flame spray facilities that have been using old paint spray booths and water wash systems and claim to have grand fathered clauses are going to be in for a surprise expense lurking in the near future as they will have to upgrade to more modern cartridge filtration systems. These systems are not cheap by any means. This may mean good business for the filtration systems manufacturers but not for the small service shop owner. Another major factor could be the tightening of workplace noise pollution standards. As everyone knows, plasma spray shops have always been operating on the upper end of the decibel spectrum with high frequency noise as well as middle frequency from hvof guns. What if they tighten that level and better acoustically designed thermal spray booths are mandated? Again, good business for the booth manufacturers but not so good for the mom and pop flame spray operator.

Then again, the oval office leadership and the congress could leave the current environmental laws unchanged, and instead approve a lot of funding for thermal spray research by way of grants and science funding through NASA, NSF and other small business research programs. They could really finance universities specializing in thermal spray research and development and that is very good for the thermal spray industry. I believe the thermal spray industry needs to get involved a little bit more in the politics of the system and try to garner sufficient funding and friendlier posture so the industry can flourish and prosper everywhere.

Thermal Spray Coatings Production Strength

2008-05-02T14:26:00.000-07:00

As you evaluate the strengths and weaknesses of the various aspects of your thermal spray coatings operations, production strengths and weaknesses become imperative to assess. After all, without solid coatings production going on, metallizing service sales would drop and profitability of the thermal spray operations would go down. Flame spray industries are pretty much like other companies that are in the service business when it comes to this aspect. Thermal spray coating companies have similar problems as other service shops like brazing and welding but are very different from batch service companies like heat treating and anodizing, when evaluating production strengths. In this post, we will deal with the production aspect of thermal spray processing.

Years ago, I had the opportunity to be involved at a thermal spray coatings company with multiple plant locations. Each of the locations was performing well as far as sales and profitability. However, the late deliveries list for all plants was always showing entries in it. Needless to say the higher-ups did not like that. When I got involved, I brought to their attention that their late deliveries list had no chance of being empty simply due to the fact that each plant’s production strength was different. “ What do you mean” is what they asked me. I took two locations as an example and explained that the first location was set up to do higher volume thermal spray only. The second location was more geared towards the very low volume - higher priced thermal spray work. The sales force dumped whatever work they could get into whatever plant was closest to the customer. Hence the plant that was a higher volume processing plant would struggle to get the low volume coatings work out in a timely fashion and they failed every time; their engineering department was not set up to crank out process operation sheets quickly enough to meet the production deadlines. On the other hand, the low volume thermal spray plant did not engineer the tooling concepts well enough, so they would process high volume thermal spray work in a highly inefficient manner and would constantly slip in delivery times. “Thermal spray is thermal spray – just coat it quickly and ship it” will not work if you want deliveries to be on time.

The only way deliveries can be held to be on time while mixing high and low volume work is if you set up the thermal spray plant to “handle” both kinds; for example, you need a tooling engineering function with sufficient expertise to tool the high volume work accordingly and a thermal spray engineering function strong enough to handle the low volume parts fast enough as far as generating process and work instruction sheets. Additionally, the thermal spray operators need to have the ability to make fast change-overs when handling multiple low volume work. All this is essential because if deliveries keep slipping all the time, then customers might potentially leave because promises were not kept.

Thermal Spray Salesman Cometh

2008-04-28T13:38:00.000-07:00

An interesting tip in this article dealing with thermal spray powders salesmen. If you are involved with the thermal spray industry, you know the thermal spray powders salesmen’s familiar countenance -- the typical thermal spray powders salesman in the business attire with a friendly smile as he (or she ) tries to win your business for the thermal spray powders, thermal spray wires, thermal spray nozzles, plasma spray guns and so on. He may also be interested in selling you an entire integrated thermal spray coating system rigged with all kinds of bells and whistles, including robotics, automated thermal spray powder feeders and so on. Of course, he forms an integral part of your thermal spray coatings operations providing you with the necessary thermal spray consumables, hopefully at a good price and in a timely fashion. Most of these flame spray salesmen and women are of a high caliber and hold themselves to high ethical and moral standards. As is always the case, a few bad apples in the basket ruin a good going thing for everybody in the group. The purpose of this write-up is to warn of a potential problem that needs to be avoided at all costs when dealing with thermal spray consumables sales people.

A long time ago, I was involved with a very price sensitive customer who had a high volume thermal spray application that was getting processed at one metallizing service company. He must have not been very happy with the price; or possibly was trying to get a better price and hence was shopping around. We got involved in the project and by superior tooling engineering and high production concepts, we were able provide the same quality at improved delivery times and at 20 % below what they were paying for the same plasma coating service. Needless to say, we won the job. We switched our plasma powder vendor just for this one contract to get better plasma powder pricing – that’s where the biggest problem came. We had never dealt with him before; but seemed like a friendly person with nothing unusual about his personality. However, suspicions arose in our minds when suddenly our customer pulled out the work and went some place else. We found out through the grapevine, that this “new” powder vendor that had observed these specific parts being sprayed , had seen the actual operation, spoken at length with the thermal spray operator, went about talking about it to somebody else at a different thermal spray shop, who took the tooling and processing concept and undercut our pricing to the end customer; who, in the interests of saving money for his company, dumped us and went with the new source. That I thought was highly unethical of this salesman. I learnt later that he was no longer involved with the thermal spray industry – thank the heavens But, the bottom line is we lost a high volume coatings application. At that point, we made a decision that I would like to share here – unless you KNOW the person visiting you, do NOT let them SEE your thermal spray booths or actual coating operations. You never know where the tongue is going to go to work based on what the eyes see.

As mentioned before, most of the consumables sales people that I have seen in the thermal spray industry would never do what this salesman did; most of them are highly ethical and maintain the confidentiality of their customers’ proprietary nature of the business. However, one bad experience can ruin a potentially high profit contract and you do not want that happening to you.

Thermal Spray Coatings in India

2008-04-22T14:36:00.000-07:00

There seems to be a tremendous amount of interest by thermal spray coatings companies in recent times in expanding into global markets especially India by setting up satellite facilities to perform thermalspray operations. This is proven by the recent establishment of a thermal spray facility in Coimbatore, India by Praxair Surface Technologies. Not limited to the large multi-national companies, even smaller metallizing service companies are curious about establishing a presence in the Indian thermal spray coatings market. This article delves a little bit into the Indian flame spray market and offers a little bit of insight for companies and individuals planning their thermal spray coatings excursion in India.

The Indian industrial scene was pretty much operating as a closed economy for several decades after independence from British rule in 1947. Gandhian principles were the norm where as far as possible indigenously manufactured goods by local entities were the only ones available to the consumer. Most of these goods were of lower quality and imports were highly taxed. Foreign investment was low and the laws were not favorable to foreign investment. However, the infrastructure was getting built during that time period. This infrastructure development was frequently disrupted by political uncertainties and several wars between neighboring countries. Thermal spray coatings was the farthest in anybody’s mind In the next forty years, several steel mills, electric power plants, textile mills and the like were established along with local air transport and road and railway transport networks were fine tuned. The last seven years have seen the Indian economy moving forward in high gear, especially with the start of the IT boom. Why should you consider increasing your thermal spray revenues by having a presence in the Indian thermal spray market – the following will hopefully clarify some thoughts.

Engineering talent available locally in India is unprecedented. There are several world class engineering colleges and Universities including the IIT, IISc, NITs, BITS, etc that produce several thousand first class engineering graduates every year; so finding local engineering talent for your thermal spray operations would not be a problem. Lesser technical functions such as masking, deburring, shipping and customer service personnel are available at a fraction of the cost of advanced industrial nations, so your cost of production can be well controlled. Thermal spray operators can be obtained from local technical schools that abound in every geographical location of the country. Several state of the art industrial parks with ample modes of transportation of finished goods are available. Thermal spray consumables are available in plenty with ease such as thermal spray powders, thermal spray masking tapes, flame spray gases, etc. The local market is abound with plenty of high volume thermal spray coatings applications such as pump manufactures, power plant fan blade manufacturers, industrial equipment manufacturers and a budding aerospace component industry that uses a lot of thermal spray coatings. With all this, getting orders for your thermal spray coatings facility should be relatively easy. With a workforce that is very fluent in English, language and communication is not a problem by any means. All this is causing a tremendous amount of interest in setting up satellite thermal spray facilities in India at the current moment. However, I believe that the market will saturate several years from now; hence, if you want to establish your presence in India, the time is ripe NOW.

Thermal Spray Operator Acceptance Contd

2008-04-19T05:19:00.000-07:00

In a previous post, we had introduced the concept of Operator Acceptance for thermal spray shops. Thermal spray coatings operations have some similarities to other manufacturing operations that have implemented Operator Acceptance programs and yet have some subtle differences. Being almost the last in the sequence of operations, thermal spray coaters are usually pressured to ship parts with shortened lead times. Implementing an Operator Acceptance quality program in your thermal spray coatings operation can significantly increase profitability levels and improve lead time deliveries if done properly. Let us consider some key elements involved in implementing such a program for your thermal spray coatings operation.

The Operator Acceptance quality program must be very well documented and must be part of the Quality Manual for your thermal spray facility. All of the procedures need to be written down and strictly adhered to. Check lists and such must be maintained and filed accordingly. The following headings will hopefully guide you towards establishing such a program and developing the associated procedures for your thermalspray coatings operations.

1. Training: The first step in implementing an operator acceptance program is documented training of the thermal spray operators in inspection and test equipment, procedures and documentation. Without proper training and its documentation, there could be doubts and confusing interpretations of testing and acceptability requirements.

2. Scope of Testing: Procedures must outline exactly what each operator is and is not allowed to test himself. For example, the procedure could explicitly state that listed thermal spray coatings operators are allowed to do visual testing and acceptance for proper coatings coverage and dimensional testing for proper coating thickness using calipers, micrometers, height gages, etc; but are NOT allowed to perform metallographic test acceptance of coating quality or on the spot dye penetrant testing for crack evaluation. Similarly procedures for thermal spray masking operators must outline for example that they are allowed to check and accept for proper masking scribe lines and overspray masking protection, etc.

3. Developing Operator Trust: This procedure allows for “trusting” a thermal spray operator, masking operator, deburrer, etc with testing his own work. The procedures will have to state for example, for what period of time will the operators and inspectors perform dual testing to ensure consistency in acceptability testing – will it be three months, six months, etc. Check lists will have to be generated with dual signatures to verify duplicate testing performances. Upon completion of the 100% duplicate testing, procedures need to be written to outline reduced duplication frequencies and duration. For example, you could have 100% duplicated testing for 3 months followed by 50% duplicated testing for 3 more months ( whereby the inspector and operator will both test every other part ) followed by 25% duplicate testing for 3 months and then complete Operator Acceptance program would be in place; thus taking 9 months for implementation.

4. Follow-up testing, Corrective Actions and Penalties: Procedures need to be in place for inspectors to spot check operators periodically to ensure the integrity of the operator acceptance program. Procedures should also state what would happen in case of discrepancies between the operator and inspector results after the program has been in place. For example, procedures could state that if one discrepancy is found then 25% duplicated testing would ensue; if two discrepancies are found then 50% duplicated testing would ensue and if three discrepancies are found then the operator would be removed from the operator acceptance program, etc. In each case though, proper corrective actions need to get generated and addressed.

5. Same Platform testing: Operator Acceptance programs can be extended to allow for operators to do testing on similar platforms for other operators. For example, there could be procedures in place to allow a bonafide thermal spray operator that performs self testing on his own parts by visual and micrometer testing to be able to accept another thermal spray operator’s parts by visual and micrometer testing. These are considered testable subjects on the same platform. The said operator however will not be allowed to test and accept for masking scribe lengths for masking testing.

As denoted above, operator acceptance programs are heavily dependant on proper procedural standards to be in place to avoid confusion on limits of testing allowability by individuals. Without strong procedures and checklists, such programs may end up with problems. With good controls in place operator acceptance programs can go a long way in reducing lead times and increasing profitability for your thermal spray operations. It may also be advisable to submit your operator acceptance programs to your key customers and get their approval to use such testing on their hardware.

Thermal Spray Operator Acceptance

2008-04-12T07:14:00.000-07:00

The thermal spray coatings industry is getting more and more competitive every day. To maintain and potentially increase profit margins, one needs to cut costs everywhere possible and cut down times every where possible in the thermal spray coatings operations in order to reduce delivery lead times. One area that can be addressed is the thermal spray inspection function. While this is important regardless of which industry your thermal spray coatings service, it is especially important for those companies that provide thermal spray coatings services to the aerospace industry. The quality requirements for aerospace thermal spray coatings is very stringent and any changes to be made to the quality control function must be reviewed very carefully so as not to jeopardize thermal spray product quality. In this post we will address thermal spray operator acceptance program as a means of cost savings.

There are some thermal spray companies that have several coating stations coating parts at a fairly good production rate; these plasma coating companies will have for example one in-process inspector that does in-process inspection covering four thermal spray booths. So if there are sixteen spray booths ( imagine them all in a row ) thermal spraying parts all day long ( music to the ears of the investor ), you end up with four in-process quality control inspectors each covering four booths. Prior to this step, there is usually an in-process inspector ( or several of them ) assigned to the masking department, that inspects proper masking per the coating process sheet requirements; because after all if the masking cut-off lines and such are not accurate then all of the subsequent operations will be incorrect. Then there is de-maksing and de-burring and you may have an in-process inspection function there. Subsequently, there might be grinding operations in-house ( for those companies that do thermal spray coat and grind all under one roof – that’s the way to increase revenues – see a previous post ), where there might be another in-process inspector. When all is said and done the parts finally go through final inspection and hopefully are acceptable to ship. All this is done with proper intentions, namely, stop putting more work into a part that has been rejected at some point and quarantine it from the normal work flow; additionally, flag the operator at the proper station, so more bad parts are not produced. However, you find an army of in-process inspectors that are really checking somebody else’s work. What if we transfer the burden of inspection and testing to the operator performing the actual work, so the complete responsibility falls on his ( or her ) shoulders — this is what is termed “Operator Acceptance”. Imagine the cost savings – no more armies of inspectors patrolling the thermal spray shop accepting and rejecting parts; imagine the time savings – sometimes an operator in one station will be waiting for release from an in-process inspector before he can proceed to the next part – and the inspector may be rightfully tied up addressing a part at a different station – this leads to lost time and therefore lost money.

While “Operator Acceptance” seems so logical and so practical a method to increase profits and speed up processing, certain key elements MUST be in place to prevent deterioration in the quality function; after all, if the quality function deteriorates, then all of the benefits obtained by implementing the program would be of no use since customers would go away elsewhere because your quality reputation would have gotten tarnished. In a subsequent post, we would go into further details in implementing an “Operator Acceptance” program for a thermal spray coatings company.

Thermal Spray Powders Inventory

2008-04-09T17:23:00.000-07:00

Plasma coatings service shops have unique requirements when it comes to thermal spray powders inventory control systems. Like every business, proper inventory controls on consumables is essential from accounting stand-points. However, here we would like to discuss the method of handling thermal spray powders and wires inventory from a metal spray processing angle. Most thermal spray coating houses have basic systems whereby approved coating powders are handed over to the flame spray operator. The needs of the powder inventory system gets a little bit more involved as we shall discuss here.
Years ago, I was involved in putting in place a PC based inventory control system for a thermal spray company for their powder crib. I was told to take an off the shelf inventory control software and adapt it to their needs. This was the beginning of the nightmare that ensued. Thermal spray coating service shops have unique requirements which off the shelf inventory software systems “generally” do not address. For example, the same coating powder – let’s say Powder 658C may be available in three different bins – one may be as received pending powder release certification, another may be in the powder certification released bin and yet another may be the same powder but made with tighter controls for specific applications. The total inventory may be 300 pounds, but the certified released inventory for non-specific jobs may only be 5 pounds; the thermal spray powder inventory software must raise red flags for the powder crib person to alert the foreman to schedule a powder release spray cycle in order to keep production moving along. Off-spec thermal spray powders purchased for non-critical jobs because of economic reasons must also be flagged accordingly. Another twist that comes to play is when thermal spray R and D departments want to specify a certain blend for research purposes; for example, there may be an on-going project where thermal spray powder A and powder B are to be blended in a certain ratio to get the final coating system; in that case, the software needs to pre-determine the availability on hand for the necessary components before the coating job can be scheduled. As you can see, the thermal spray powders inventory software system may need to inter-weave significantly with other areas of operations such as spray scheduling and thermal spray R&D in order to be effective enough as an automation tool.
Needless to say, I decided to scrap the off-the shelf inventory software that was purchased and wrote the whole code from scratch – the result was a superbly functional system that gave reports to the other departments – obviously also to the accounting gurus – because the bottom-line of any business including the thermal spray business is making money

Thermal Spray Tooling Efficiency

2008-04-06T08:09:00.000-07:00

In your thermal spray coatings service shop, hopefully, “this job is a loser” is NOT a term you hear too often But the reality is, there have often been times where a thermal spray job has not been profitable. Metallizing service shops come across this situation every so often where the price you are paid for a certain flame spray work does not meet the profit expectations of the higher ups in the thermal spray company. But before you call up your customer and ask him to void the thermal spray contract, you need to investigate if there are ways and means for you to turn the situation around and convert that loser metallizing job into a profitable thermal spray winner. While there are several factors that may have contributed to the specific job being a losing thermal spray contract, many times it is inefficient tooling that is the culprit.

Tooling design for thermal spray applications is an art in itself that can produce phenomenal increases in productivity and therefore profit. Indexing turntables go a long way in increasing thermal spray operator throughput. Especially in high volume jobs, excellence in thermal spray tooling makes a big difference. For example, I had come across a thermal spray application, that required a coating of straight aluminum oxide – no bond coat; thermal spray coating thickness was to be .003 to .005 . Parts were about .350 in diameter and about an inch or so long with the coating to be applied on the od – no masking required. Here was the catch – the aluminum oxide plasma sprayed coating had to be sold at very low pricing and the volume was about 5,000 pieces per week ( Wouldn’t you like a contract like that ? ) This job looked like a waste of effort right at the quotation stage; however, the way this was processed was as follows: an eight station indexing table was built with an up-down mechanical - pneumatic traverse for the plasma spray gun. The gun was never shut off and neither was the thermal spray powder feeder. Gun angle was about 15 degree down angle with two air jets. All that the operator had to do was to unload the part in one station and reload the next part in the same station while the plasma spray gun was thermal spraying the second station; upon completion of the coating, the table indexed to the next station with the virgin part to be coated, while the coated piece was cooling in the coated station and had enough cooling time by the time it reached the operator to perform the unload / load operation. The rate of production was about 180 to 200 pieces per hour; thus allowing easy production of about 1,000 pieces per day with sufficient time for gun maintenance, tooling maintenance and so on. Suddenly, that became a very very profitable thermal spray contract that lasted for years and years.

Another example here. Aerospace knife edge seals are usually coated with a plasma thermal sprayed nickel-aluminum bond coat followed by an aluminum oxide/titanium dioxide top coat. In one instance, we would receive about 20 parts to be thermalsprayed per day. These parts were such a pain to thermal spray – because the way they were processed was as follows: the parts were fixtured on to a “Y” type fixture mounted to a turn-table and the plasma spray gun was mounted on to an “UP / DOWN” traverse. The gun had a “down” angle of about 30 degrees. Bond coat was applied on to one side of the knife edge seal teeth for all of the 20 or so pieces. Then the operator would flip the parts and do the “other” side of the seal teeth. The same process was then repeated for the application of the alumina/titania top coat. Imagine the nightmare of part handling – each part was handled four times right in the thermal spray booth – to add to this circus, there was the inspection department that measured each part four times – twice for the bond coat and twice for the top coat. The way the parts were priced, there was very minimal profit to be made. Add to this the powder wastage as the gun stayed outside the part more than it stayed on the part for both the bond coat and the top coat plasma spray operations. Incremental steps were taken to increase the profit margin on this set of parts as follows. First, the operator coated the first side of the seal teeth, flipped the part and coated the second side. Thus all the parts received bond coat operations first. Then all the parts were top coated – first side first and then flip and top coat the second side. Inspection was reduced to once for bond coat and once for top coat. There seemed to be some potential light at the end of the tunnel. After running like this for several months, tooling concept was finally changed. Four knife edge seal parts were fixtured on to the turn table at once with lids in between and at the top to prevent any inside overspray. Traverse length was increased and now suddenly powder target efficiency went up dramatically ( Visualize the happiness on the accountant’s face ) Now instead of one side of one part getting coated, you had one side of four parts getting coated at once. Then the operator flipped all four parts and then did the same coating operation for the other side of all parts. Then of course the top coat operation was performed; again four parts at a time. This was a major step forward leading to more profit per part. The progress did not stop with that. A major modification was made to the up-down traverse unit to be able to flip the angle of the gun mount upon reaching the end of the traverse. For example, if the gun was moving on the down stroke at 30 degrees down angle then at the end of the down stroke, just before the up stroke began, the gun would flip to a 30 degree up angle so both sides of the seal teeth can be coated at once. Combine this with four parts being done at once – now you had an efficient system where 4 knife edge seals were bond coated at once, inspected and then top coated at once with an up-down traverse that went with a down angle on the down stroke and an up angle on the up stroke. The gun angles could be changed; namely, you could go down at a thirty degree angle but go up at a fifteen degree angle; this is needed because of certain seal teeth geometries that required this kind of variation in the angle of spray between the down stroke and the up-stroke. This resulted in such high profits that everybody involved was thrilled to the skies with the improvement in processing using better tooling and better processing techniques combined. Of course, the last evolution of this exercise ended in the introduction of robotics with the robotic programming optimized as discussed in a previous post. All along, the tooling was optimized per the thermal spray processing adhered to by using rubber backings and quick clamps as opposed to threaded fittings and so on to enable quick part loading and unloading.

Robotics

2008-04-05T13:00:00.000-07:00

Robotics automation is being introduced in many coatings shops in their gun manipulation. Simple gun manipulation systems such as mechanical “Up / Down” units to simple robotic systems to very sophisticated robotic systems are all finding place in thermal spray shops worldwide. In addition to reducing operator fatigue quite evident in manual operations, use of robotics in automation allows to achieve one more step towards thermalsprayedcoatings repeatability. By the use of robotics , the thermal spray gun travel velocity can be controlled consistently as well as spray distance can be maintained consistently even on complicated part geometries. In more sophisticated robotics controlled thermal spray coating systems, where the “Powder ON” and “Powder OFF” controls, turntable rotation checks, rpms as wells as “Feed Rate Controls” are automated and integrated with the robotics program, there is further progress towards coating repeatability by reducing the variables involved in the application of thermal spray coatings.

An important but frequently overlooked aspect in thermal spray shops using robotic systems is the programming finesse and capabilities of the robot programmer. Sure, the robot itself could be quite sophisticated with multiple axes capabilities and so on, but what about the human being that is doing the robot programming ? Thermal spray shops that simply employ the services of a robotics software engineer are liable to gain nearly not as much as thermal spray companies that involve a seasoned thermal spray engineer who “knows” the coating process to learn the ins and outs of robotics and have him do the programming. Conversely, if the person starting out in the robotic thermal spray cell is simply trained only in software, then he should be trained in the thermal spray process as well in order to get the most out of the automated spray cell.

In light of the aforementioned point, I would like to give a real world example dealing ONLY with thermal spray gun movement using robotic systems. I was once involved with a thermal spray coating company that was coating the same family of parts with the same plasma spray coating material for years by manual hand spray technique. Later, they introduced automation in that plasma spray booth by way of a simple pneumatic “UP / DOWN” traverse. Things looked up – because they were getting consistent coatings without operator skill dependance and at the same time reducing operator fatigue. The company was making all kinds of profits and they wanted to step up to the modern world and so invested in a fairly sophisticated robotic system. They had always been very good at collecting data and logging it well – they had years of data – all kinds of data ( more about data analysis in a future post ). They found suddenly that the plasma spray powder usage in that booth had gone up since they had installed this expensive robot. That is when I was asked to step in. What was happening was that they had a programmed “Gun Light Point” where the gun would be lit, powder turned ON, stabilized and then move to the part, finish coating the part and then move back to the “Gun Light Point” and then powder turned OFF and the gun turned OFF. This point in space was quite a distance away from the part; whereas the old UP / DOWN machine stopped right above the part. This may not sound like much, but remember they coated the same part family hundreds of times a day and then day after day – ( ever wonder where those high volume thermal spray jobs are nowadays ? – don’t worry they are still there – you just need to look harder :-) ) The five additional seconds the robot arm was moving TO the part at the start phase and AWAY from the part at the end phase was enough to make a difference in the powder usage data. So I moved it right above and to the right of the part with a very quick move.

There are other kinds of tricks that the programmer can do to save on thermal spray powders by the use of robotics. For example, many times the thermal spray gun will move at an “UP - Angle” during the upward traverse and with a “DOWN - Angle” during the downward traverse. Well, when the gun switches the angle of travel, you need to code the robotic program as an arc whose center point is calculated as being away from the the robotic arm end point by [ the gun length and any extensions to it PLUS the spray distance] . This will allow for a very quick but smooth gun angle change, so that very little thermal spray powder is wasted not to mention the savings in time during the angle changeover. I instituted this procedure on ALL part families where gun angles changed at the end of the traverse. ( a note here: the thermal spray gun traverse could be up/down or side/to/side – doesn’t matter – the arc can be described either way. )

Of course, simple things like how much of idle spray the gun is performing, how far of an overshoot is handled, etc are simple enough to observe and rectify. Remember, robotics must be properly programmed and used so that the goal is to reduce operator fatigue, produce consistent thermal spray coatings and conserve on thermal spray powders. Then the investment will pay off.

Thermal Spray Exports

2008-04-04T13:14:00.000-07:00

Thermal spray coatings services shops are always looking for ways and means to increase sales. Exporting thermal spray coatings IS a viable alternative. We are not talking about exporting thermal spray consumables like thermal spray powders or thermalspray wires, gun nozzles and the like but rather of thermal spray coatings. Note that this is going to take a lot of work on your part. Obviously, it is cost prohibitive to make a component in China, ship it to USA, apply a thermal spray coating and then ship it back to China. Conversely, it is equally expensive to make a part in the USA, ship it to a flame spray shop in India, get it coated and ship it back to the USA – the shipping costs alone will eat up all the profits. If that is the case then how do you participate in the globalized economy being in the thermal spray coatings business?

There are two sure-fire and time-tested ways in which you can sell your thermal spray coating services to overseas companies – this is applicable whether you operate a metallizing shop in the USA, UK, China, Japan, India, Italy or anywhere in the world. The first method is to locate an end user in the country where you are located and a part manufacturer in the country of origin. For example, if you are located in the USA, then locate a customer in the USA that buys a component complete that has thermalsprayedcoatings as a significant operation. Now locate a part manufacturer in Asia who makes the part; in turn, you perform the thermal spray coatings operation and then ship the part to the local end-user – this way the importing is done on partially finished goods rather than a complete entity. Conversely, if there is a customer in India for example, that purchases a component that has thermalsprayed coatings from the USA, you act as the thermal spray supplier to the component producer in the USA and ship the part to India. This is the easiest approach to marketing your thermal spray coatings services to a global customer base.

Another method is to change your frame of mind as a thermal spray coatings supplier to a component supplier – the key being that the component you supply needs to have thermal sprayed coatings as a significant part of the component processing. So you need to first identify a component, get it manufactured up to the thermal spray operation, then you perform the thermal spray operation and then continue to outsource any subsequent operations and then ship the part complete. Generally in the thermal spray industry, the machining vendor takes on the major responsibility and simply outsources the plasma, LPPS or hvof thermal spray portion and hence thermal spray shops many times end up with making up the lost time and cost overruns incurred by the machining vendor. Turn the tables and your profits can soar. Of course, this involves a tremendous amount of work up front for you, the thermal spray operator. This technique brings with it other advantages too. Once you have identified a “widget” as discussed, you can have level loading of your machinery – in other words, if work is slow in your shop at some point, you can fill it with the “widget” work to keep equipment down time to a minimum. Why should thermal spray shops simply be the “special process” people – instead take complete control of the whole component – and you know what your profit margins can be higher because now you make a little bit more of a margin on every operation that you outsourced.

Thermal Spray Coat and Grind

2008-04-03T13:11:00.000-07:00

The thermal spray coatings industry occupies a niche in the industrial goods and services market. There are several opportunities to make money in the field of thermal sprayed coatings. From aerospace to ground turbine to other commercial industrial applications, thermal spray coatings are being used extensively to improve metallurgical characteristics of components. By the same token, competition within the thermal spray industry is fierce, with only the strong thermalspray companies successful and the weaker metallizing service shops barely making it. If you are already in the thermal spray coatings business, then one way in which you can strengthen your position against your friendly flame spray competitors is by adding other value added services. For example, many times components require a thermal spray coating followed by grinding to size. By offering thermal coating and grinding services as a one stop shop, you will enhance the value added to your customers. Better yet, thermal spray, grind to size and also provide fluorescent penetrant inspection services to detect cracks in the coating or in the grinding operations. By the way, once these processes are in place, you can offer them separately as well – for example offer grinding services followed by FPI for other thermal spray shops. This is called selling intermediates. Grinding thermal spray coatings is an art by itself. Not everyone with a grinding machine can grind plasma coatings and hvof coatings successfully without introducing grind cracks and other defects.

If you are not involved currently with thermal spray coatings, then may be it is time you look to getting started with plasma, hvof and wire arc sprayed coatings; especially, if you are currently outsourcing your flame spray coating requirements. You don’t have to start off in an elaborate manner. Start with one thermal spray booth and learn the ins and outs of the thermal spray process and technology and may be one day, your thermal spray cell can stand as an independent profit center. For example, if you are machining a component from bar stock and sending it out to be plasma sprayed, why not do both the processes and sell it to your customer as a complete part? I had the opportunity of being in a company once that machined a part from bar stock, heat treated and brazed another component to it, thermal sprayed it, performed a small welding operation to it, then performed magnetic particle inspection to ensure absence of weld cracks, sent it out for a plating operation and then sold the part to the customer as a finished piece. Notice that other than the plating operation, everything else was done under one roof. They could significantly reduce the delivery lead times for this component as opposed to their competitors that outsourced most of the work except one or two that they were capable of performing.

In this day and age, when manufacturing shops are trying hard to increase their revenues, getting into the thermal spray coatings business may just be the added niche that sets your shop apart from your friendly competitors

Thermal Spray Consumables Consignments

2008-04-02T14:31:00.000-07:00

In a previous article, we discussed reducing the cost of thermal spray consumables by placing blanket orders on repeat use items such as certain thermal spray powders, thermal spray gun nozzles, etc. This is one method by which you can try to keep a lid on recurring costs associated with purchase of thermal spray powders and the like. There is another technique used by some companies in their attempt to increase the bottom line of their thermal spray business. We will discuss that in this article.

Again, the bulk of the burden of controlling costs here is going to fall on the purchasing function of your thermal spray operations. Lets take thermal spray powders and thermal spray wires for example. You can negotiate with your thermal spray powder supplier to put key thermal spray powders on consignment at your thermal spray shop and give him a report at the end of every month regarding usage; you then pay only for what is used. You get the benefit of controlling and optimizing cash flow and he gets the benefit of locking in your business for term of future that has been agreed upon. The same method can be used for grit blasting grit, thermal spray gun nozzles and the like. The key though is you must make sure your accounts payables are in line and payments made on time. Because once your supplier gets delayed payments, he is more than unlikely to entertain consigned inventories and you would have killed the golden goose. From an accounting stand-point, consigned inventories do not appear as cash tied up in inventory and so your books look good also. Additionally, thermal spray shops that deal with aerospace and military contracts have to do a powder release laboratory sample for every new lot of thermal spray powder or thermal spray wire; ( in all actuality EVERY thermal spray shop should do this regardless of end customer application aerospace or otherwise ). When you place a large consignment order, then chances are there is one big lot tied to one lot number rather than 20 different lot numbers with small quantities in each; hence you also save the costs of the additional powder release spray time and associated metallurgical testing costs.

In summary, consigned inventories of thermal spray consumables such as thermal spray powders, thermal spray wires, grit blasting grits, thermal spray nozzles, masking tapes and masking compounds go a long way in improving the bottom line of your thermal spray business and hence make every effort towards implementing them in your own company.

Thermal Spray Consumables Cost Control

2008-04-01T13:20:00.000-07:00

Thermal spray consumables expense is a recurring item that, if not watched over carefully, can eat up into profit margins in a big way. The consumables expense is a critical item for all industries and not limited to the thermal spray coatings business. In this article, we can discuss controlling the expenses of critical thermal spray consumables so that profit margins can be protected and increased if possible. Not all thermal spray consumables are amenable to cost control; there are some factors that are beyond control and these have to be taken in as they are. But steps taken to subdue the effects of flame spray cost increases will definitely pay off in increasing the bottom line of your thermal spray business.

A lot of burden regarding cost control of thermal spray consumables will fall on the purchasing initiative of your company. For example, lets take thermal spray powders. If you are utilizing 200 pounds of a certain powder, say Metco 73F or its equivalent, then there is no cost benefits to you if you keep buying 200 pounds every month. Instead, make a deal with the thermal spray powder supplier and place a blanket order for 2,400 pounds to be released 200 pounds every month for a year and negotiate to get better pricing because of increased volume order. Of course you are committing to this higher volume, but that’s what is needed if you want to reduce thermal spray powder costs. You may want to discuss with your customer regarding his commitment to purchasing from you and in turn let him have a small reduction in price in exchange for his commitment. The same applies to thermal spray masking consumables – why buy 10 rolls of tape every month at a higher price when you can get a much better deal by placing a blanket order for 120 rolls of tape to be released 10 rolls every month for a year. You will need to pay only for the released material so your cash flow will not get affected. This process needs to be addressed through out your thermal spray business; for example what about plasma spray nozzles – get an idea of how many nozzles you plan to use over the next twelve to fourteen months and put it in a blanket and get blanket pricing. In addition to getting a lower cost because you are placing a higher volume order, you will get your thermal spray consumables supplied to you in a timely manner; namely, your thermal spray line won’t be sitting idle waiting for a specific thermal spray powder or tape or nozzle, etc. Negotiating with thermal spray gas suppliers may be more difficult. Gas suppliers are usually unwilling to negotiate too much. There are some exceptions though; if you are dealing with a smaller gas distributor who also sells thermal spray powders ( and there are a few of them around ), you can try to combine the two purchases and save on costs. Hence, place blanket orders after evaluating your thermal spray powders and associated consumables usage forecast and you can make a significant difference to the bottom-line of your thermal spray coatings business.

Thermal Spray Reciprocal Sales

2008-03-29T05:44:00.000-07:00

Increasing thermal spray coating sales is probably at the top of priorities for most metallizing service shops in today’s market. One has to be innovative in the sales approach in order to be successful in grabbing up contracts in the highly competitive thermal spray coatings market. Gone are the days when you simply put up a plasma spray coating booth and expect the phones to ring off the hook. In this post, we will address a technique by which you can increase your thermal spray coating sales leads. We will call this the thermal spray reciprocal sales approach as discussed below.

Years ago, a sales inquiry came about an application that could not be solved by thermal spray coating techniques in an economical manner; the inside salesman told the inquiring party that we could not help and that was the end of it. I came to know of it and said to myself, the solution for this person’s problem can be obtained by simply changing the base material of the component from steel to aluminum and anodizing it. So, I called the lead, explained to him that to solve his problem economically, he needs to change his base material to aluminum and simply hardcoat anodize it and proceeded to give him two companies that were local to him that were in the anodizing business. He was very happy. I proceeded to call the two aluminum hardcoat anodizing firms and gave them the name and contact of this inquiry and asked them if they would in turn send us any thermal spray leads that they may receive! Believe it or not, we did receive a few leads from the two aluminum anodizing companies out of which one turned out to be a really profitable contract. I then instituted this approach as a matter of requirement for ALL incoming sales inquiries.

This is how it would work. Obviously, one has to spend some time in learning the various options for modifying surfaces and essentially become a surface engineering guru. You need to know about methods other than metallizing techniques that are employed to solve wear, insulation, abrasion resistance problems and so on. Then you need to make contacts with a small select group of companies that offer these specialized services such as anodizing for example. You need to have a general understanding – no contracts or other legalese or partnerships – simply a handshake that says if you receive any inquiries that are beyond the plasmaspray world but can be solved lets say by plating or hardcoat anodizing, as it happened in my case, then you would refer the contact to your plating or anodizing “preferred source”; conversely, if your plating or anodizing contact receives a thermal spray solvable inquiry, he would refer to you as the “preferred source”. This “one-hand-helps-the-other” approach can lead to some very good profitable contracts. Now, note that you may have to spend some time with your “preferred source” companies to educate them a little bit more about thermal spraying than they may be aware of, but that is essential so they send screened leads and not simply poor quality contacts. Powder coating companies are another major source of thermal spray leads. Companies dealing with plastic coatings can usually provide leads for abrasion resistant coatings and high temperature furnace component companies can provide TBC leads.

This technique can some times provide unusually good results for both companies. For example, there was an application where a customer needed a teflon coating dispersed in a harder matrix. There our reciprocal sales technique worked to the benefit of two coating companies. Because, we received the parts, coated them with plasma sprayed nickel chromium aluminum ytrrium and then sent it to a local company that specialized in dip-spin teflon coatings that was used to infiltrate the porosity of our plasma coating and the customer was extremely happy with the end product performance.

Thermal Spray Competition

2008-03-27T14:18:00.000-07:00

Thermal spray coatings shops worldwide are seeing unprecedented growth in recent times. New thermal spray and metallizing service shops are sprouting up all over the world nowadays. While that is good for the thermal spray industry in general, the levels of competition are getting more and more fierce day by day. How do you maintain your competitive edge in the midst of this feeding frenzy in the thermal spray coatings business? Consider the fact that thirty or forty years ago, if you got into the thermal spray business, your work load was pretty much guaranteed. Not now. You need to stay ahead of your competitors if you want to simply survive let alone grow in the thermal spray and flame spray coatings business.

The first step in being successful is to follow the age old adage : “ Know your competitors “. Let us spend some time discussing this. Years ago, I was working at a thermal spray shop that was acquired by a bigger company whose main line of work was NOT in the thermal spray business. The big boss came up and asked us who our competitors were and wanted us to give IN WRITING a brief description of their strengths, weaknesses, employee count, sales volume, key personnel and so on and we failed miserably. We could name our competitors but that was about it. He said that is bad understanding of who we were fighting against in the marketplace. How can you succeed when you do not know who your enemy ( figuratively speaking of course ) is?
That is great advice I thought and it is applicable even today to all industries including the thermal spray coatings business whether you are strong in plasma spray, hvof spray, LPPS or any other special coatings business. There are easy ways to get basic information about any company – credit reporting agencies and company information agencies are all abound with information. Identify five or six major competitors to your thermal spray operations and study them in detail and write down the data. You need to use judgement in isolating your competitors; for example, if your thermal spray coatings business is in northeastern United States, then chances are the thermal spray shop in southern California or Mexico is not a viable competitor; by the same token if your thermal spray service shop is in southern India in Chennai, then the thermal spray shop in Mumbai is potentially a viable competitor. Write down their key personnel, their annual sales, their loan burden, their strengths and weaknesses, their key markets and so on. You then need to concentrate on your improving your strengths and eliminating your weaknesses and then compete fiercely in order to succeed.

Thermal Spray Plant Layout

2008-03-25T14:23:00.000-07:00

Thermal Spray Coatings service shops are facing increasing competition nowadays. In order to compete effectively, today’s thermal spray shops have to watch every aspect of the business in order to squeeze costs out of the thermalsprayedcoatings operation. A rarely looked upon area of cost control in thermal spray coatings shops is facility layout. An improperly designed thermal spray plant layout can cost significant amounts of money in everyday flame spray operations which leads directly to lowered profit margins in your thermal spray business. Another aspect is a badly laid out plant can have safety hazards. For detailed discussions on safety aspects, you are invited to visit my site http://safetyfirstatwork.blogspot.com/

The layout of the thermal spray shop should enable easy and smooth flow of parts from the receiving area back to the shipping area. Since you cannot have a long building like a bowling alley, I prefer the looping approach where there is a loop between the receiving and shipping departments which are usually in the same vicinity. When parts flow smoothly from one area or department to another area in a sequential manner in the order of operations to be performed, then excessive mileage is not associated with part movement and therefore you have less chances of people walking around all day moving parts back and forth between departments. This walking around all day process leads to operator fatigue and hence lower productivity towards the end of the production shift. Additionally, thermal spray shops that deal with aerospace customers usually deal with parts that are very expensive to begin with and hence excessive mileage on parts can lead to higher levels of potential dings and dents and other part damages.

To give you an example, there was one thermal spray shop where the masking area was next to the receiving area, followed by quality control inspection, followed by degreasing and part cleaning operations followed by the grit blasting area and the parts then looped around to the thermal spray coating booths and then back to quality control inspection and then to shipping. Total chaos everyday – everybody runs around all day and the thermal spray business was really not operating at its best. What they should have done is to back off, take a deep breath, spend some money and rearranging departments, so that the quality control inspection department is right next to receiving and shipping, followed by the degreasing and cleaning operations, followed by masking and then grit blasting and then loop around to the thermal spray coating booths and thence to quality control inspection for final inspection and simply move to shipping. This way parts flow freely and there is harmony every day in the thermal spray business. By organizing the layout of the plant to match the sequence of the thermal spray operations, your bottom line will improve because you are saving on labor inputs into each part. Thermal spray operators need to be coating parts not moving parts back and forth. Of course, process engineering and office personnel can be a little bit moved away from the flow of parts and that doesn’t really cause too much of a problem.

Altering an existing thermal spray shop’s set-up will cost money in the short term; but if sufficient thought goes into it and it is properly done, then the long term benefits outweigh the short term hassles.

Coating Matrix Examples

2008-03-24T13:41:00.000-07:00

In a previous post, we discussed the methods for developing a thermal spray coating designation matrix to help ensure consistent sales volume. In this post, I would like to give a couple of examples of how the thermal spray coating designation matrix could look like. You can adapt a similar method to develop your own unique matrix of thermal spray coatings designations for your company.

Lets say your company is called A Thermal Spray Coatings Company. The following is one example of a thermal spray coatings designation table:

TSC-10-A: Wear Resistant Carbide ( Internal Spec IS-TSC-10-A )
TSC-10-B: Wear Resistant Carbide ( Internal Spec IS-TSC-10-B )
TSC-10-C: Wear Resistant Carbide ( Internal Spec IS-TSC-10-C )
TSC-10-D: Dielectric Coating ( Internal Spec IS-TSC-10-D )
TSC-10-E: Dielectric Coating ( Internal Spec IS-TSC-10-E )
TSC-10-F: Rebuild Surface Coating ( Internal Spec IS-TSC-10-F )
TSC-11-A: Wear Resistant Carbide ( Internal Spec IS-TSC-11-A )
TSC-11-B: Wear Resistant Carbide ( Internal Spec IS-TSC-11-B )
TSC-11-C: Dielectric Coating ( Internal Spec IS-TSC-11-C )
TSC-11-D: Rebuild Surface Coating ( Internal Spec IS-TSC-11-D )
TSC-12-A: Re-build Surface Coating ( Internal Spec IS-TSC-12-A)
TSC-99-A: Impregnated Coating ( Internal Spec IS-TSC-99-A )

As you can see, the first three letters is the acronym of your company’s name. The second number defines the thermal spray process family, namely 10 stands for plasma spray, 11 stands for hvof thermal spray, 12 stands for twin-wire-arc spray, 99 stands for something proprietary and so on. The third unit stands for the thermal spray coating material family, for example A stands for Tungsten Carbide Cobalt; B stands for a different class of Tungsten Carbide Cobalt, C stands for Chrome Carbide Nickel Chrome; D stands for Pure Alumina; E stands for Alumina-Titania and so on.

You can proceed to freely distribute your thermal spray coatings designation table as above to your customer, but not provide the Internal Specification for free distribution. Remember that is your internal specification that will outline exactly how to process that specific thermal spray coating as far as processing, evaluation, etc and the customer has no business looking into that without, at the very least, signing a confidentiality agreement. The internal specification will determine what thermal spray process will be used or what alloy blends are to be used and any other special instructions to the OPERATOR to ensure promised product quality and metallurgical characteristics.

I have also come across thermal spray coatings designations, which are intentionally mis-numbered to throw other thermal spray coatings competitors into a never ending loop. For example, it is very easy to de-code your coating designation if it is kept in such a simple format as above. A simple technique that circumvents this is to designate for example APQ-5544 as the designation for hvof thermal sprayed tungsten carbide while PRK-9943 would be plasma sprayed tungsten carbide – notice there is no company acronym or logical assignment of thermal spray process families or material chemistry families. One can argue that science is for everybody to know and knowledge is for everybody to spread; however, in many instances significant effort is spent in developing just the right thermal spray coatings parameters for the application at hand and every company that spends that kind of effort in time and money does deserve to hold on to the proprietary coatings processing techniques so they get rewarded with the sales of thermal spray coatings services that they duly deserve.

Coating Designations - Contd

2008-03-22T09:06:00.000-07:00

In a previous post, we discussed the advantages of developing a thermal spray coating designation matrix to help ensure consistent sales volume. In this post, I would like to describe the steps involved in developing a thermal spray coating designation matrix. You could use your own indigenous method – the end result being a unique matrix of thermal spray coatings designations for your own organization.

Firstly, not all thermal spray coating shops have all of the thermal spray coating technologies available at their disposal; for example, you may have the capability for air plasma spray and hvof thermal spray, but no twin-wire-arc thermal spray process capability; or else, you may not have the capability for hvof thermal spray but have the capability for Low Pressure Plasma Spray. So firstly, your matrix may get divided by process capabilities such as plasma sprayed coatings, hvof coatings, wire-arc thermal spray coatings and so on. The second subset within this could be the material driven families such as tungsten carbide cobalt, chrome carbide nickel chrome, T-800 and so on. Another method for developing the matrix could be by metallurgical properties imparted by the thermal spray coating – such as a family of wear resistant coatings, a family of electrical properties coatings, a family of abradables and so on and within this develop a subset by thermal spray process capability and within that subset, have a designation by coating chemistry – for example, under the family of wear resistant coatings, you may have plasma sprayed tungsten carbide-cobalt, plasma sprayed chrome carbide nickel chrome, HVOF thermal sprayed tungsten carbide-cobalt, HVOF thermal spray coating of chrome-carbide, and so on – I believe you get the picture. You may additionally have specialized family of proprietary coatings, for example a thermal sprayed coating base with a silicone release impregnation or a plasma tungsten arc coating with a subsequent fusing operation – these would form a separate family.

Developing the thermal spray coating designation matrix has other advantages besides the immediate increasing sales objective. Firstly, it gives you a better understanding of your own thermal spray coatings business – even though you may have been providing thermal spray services for several years, the matrix kind of summarizes for your own self what all you can provide your customer – sort of reorganizing capabilities, a kind of inventory taking per se and proper filing of all the clutter. Secondly, it may give you insights into developing new combinations of coatings and steer you toward developing newer coating families based upon your current capabilities. For example, how about developing a family of thermal sprayed hvof bond coat of CoNiCrAly with a top coat of plasma sprayed thermal barrier zirconia-8%yttria and another family with the same bond coat but with a top coat of plasma sprayed thermal barrier zirconia-12% yttria. This is just one example. Notice that this did not involve buying any more capital thermal spray equipment at all

One thing that I would not do is develop a thermal spray coatings designation matrix by industry – that is a bad idea – for example if you developed a family by printing industry coatings, pump coatings, automotive header coatings and so on then you are blindfolding potential future thermal spray coatings entry into industries you have never been to and you will be revising and rebuilding the matrix too often. Of course, the thermal spray coatings designation matrix must be kept up to date as you add newer products but you shouldn’t be making a career out of it simply because you started it the wrong way In a future post, we will address the thermal spray coatings designation matrix in a little bit of more detail.

Coating Designations

2008-03-21T12:20:00.003-07:00

Lets face it – the thermal spray coatings business is getting more and more competitive every day. In order to succeed, you need to not only find newer applications for thermal spray that can be directed to your shop, but also keep the current thermal spray business that you have from going away elsewhere. I remember a thermal spray sales manager once told me to imagine this process like a shepherd would manage – he said “you can’t let the sheep you got to get away ” This two-fold approach is necessary to keep sales consistent and growing in your thermal spray coatings business model. Assigning thermal spray coating designations is one more step in the right direction in accomplishing this goal.

Many times you will deal with engineers at your potential customers’ plant, that are interested in you providing with a thermal spray coatings solution to their applications problem – lets say it is fretting wear resistance. They are most interested in the end result, namely, getting a thermal spray coating that will increase the resistance to fretting wear. They are really not interested in the means to the end – namely, they do not care whether you chose copper-nickel-indium plasma sprayed or you chose some other material sprayed by the twin-wire-arc thermal spray process, as long as the specifications of dimensional control and metallurgical characteristics are met. Hence it doesn’t do you a whole lot of good to completely describe the means you took to achieve the end result; because now your customer can very easily go to the shop down the street and request that they apply the same means that you did because the customer knows that the end will be met. However, if he simply has a designated thermal spray coating number to go by, this shopping for the lowest price approach is somewhat subdued. The thermal spray shop down the street can still take a fairly good guess at what you did but you do not leave the door of the house open All that your customer has is your company’s thermal spray coating designation for the application solution.

It becomes further more advantageous, if you can have this thermal spray coating designation number specified in your customers’ blue print for the component at hand – for example, processing note number 12 could say, “Send part to Vendor (your company’s name) for Coating Designation: #ABC.” Now, their purchasing agent has no choice but to send out the thermal spray coatings work to you and you end up with a goose that lays a golden egg every time. This technique is not something new. Several companies with sophisticated marketing personnel use this method all the time. The smaller thermal spray companies that have not spent the time in developing the coating designations matrices are the ones that pay the price of potentially losing out on repeat coatings work to the larger thermal spray shops. Of course, this is going to take time effort, but the results will definitely justify the hours of work you put into it.

In a future post, we will go into the details of how to set up a thermal spray coatings designations matrix.

Repeat Coatings Business

2008-03-21T12:20:00.002-07:00

In this article, we will deal with methods to increase thermal spray sales. As you may know, there are two kinds of sales in any endeavor – the first is one time sales and the second is repeat sales – thermal spray coating sales is no different. The time and effort spent in finding a customer who is going to purchase your thermal spray coating services on a one-time basis is better spent in finding and nurturing a customer who will potentially buy your thermal spray coatings service over and over again. There is a word of caution – there are times when an engineer who has never used thermal spray coatings in the past has an application problem where he wants to try the hvof technology or plasma spray coatings technology to see if it will solve his problem – this case could very well turn out to be extremely profitable for you if handled properly and end up with a lot of repeat business. What is not really worth wasting time on is in the occasional user of thermal spray coatings as a way to repair an old pump shaft or rebuilding of an old machine component – you may never see that customer wanting your thermal spray services for the next couple of years!

Repeat customers can be developed for example by dealing directly with the OEM pump manufacturers or valve manufacturers or other component manufacturers and developing a wear-resistant coating system for instance that will allow them to use a cheaper base material with a tungsten carbide coating – now every component they manufacture will end up coming to your shop for plasma spray coating service. Or for that matter, introduce an anti-fretting copper-nickel-indium coating to a systems manufacturer where couple of their components face significant fretting wear and you got a lot of business for a long time. I have always held the stand that it is more profitable to make a smaller margin on a large volume of parts than a large margin on a handful of parts. High volume thermal spray orders keeps booths running all the time and machine utilization gets optimized, thermal spray powders can be purchased in volume at a lower price, thermal spray nozzles and other consumables can be bought with significant discounts, robotic automation can be introduced and so on.

There is a price to pay to get those higher volume coating contracts. This is where the sales engineering and applications engineering skills of your thermal spray shop come into life. Everybody wants that multi-year tungsten carbide coating work – but how many are willing to put in the effort? Remember , no pains no gains. Hence you will have to identify the opportunity, understand the application and the problem – whether it is corrosion, sliding wear, fretting wear, impact wear, thermal barrier requirement, electrical conductivity or resistivity requirement, etc and then come up with the correct coating solution and last but not the least, deliver a cost effective thermal spray coating solution. Now you end up with a high volume coatings contract and can start making some serious money !

Thermal Spray Sales Growth

2008-03-21T12:20:00.001-07:00

The thermal spray coatings shop I was working in had sales that were pathetic. The workers were simply saying "Bring in more work !!" They were absolutely right. Firstly, the sales team needs to be well educated on the product they are selling. They cannot look at thermal spray as a service, because then the customer will kick you around like a soccer-ball. You cannot have sales people that walk into a customer's plant, meet with somebody, hand over a "line-card", exchange business cards and come back home. He needs to know the customer's application and go in as a thermal spray applications engineer that is going to solve a problem. Now, many times that may not be an engineering problem; the coating specification may already be in existance; it might simply be that his current supplier is too expensive, too slow, bad in quality, unreasonable in payment terms, have bad doumentation ( I had an instance where the problem was that my customer was simply tired of the constant calls he was receiving from his accounts payable department because his supplier's invoicing was convoluted and un-fathomable every single time !! ( ever heard of this problem existing in today's world? ). The thermal spray coatings salesman needs to be able to address any or all of the above with confidence first. If he doesn't bring in enough work, then fire him -- there is plenty of opportunites to get thermal spray business in today's market. So, the first step is that the salesman must be knowledgeable in thermal spray technology. I was at a thermal spray shop once, where they hired a man, put him in receiving, then in cleaning, then in masking, then in grit blasting, then in plasma spraying, then in de-burring, then in shipping, then in process-sheet writing and then they put him in sales -- wow ! what a great salesman he turned out to be ! Ever wonder why !
In my case, I couldn't find anybody like that in the pool of people we had, so I myself became the part-time salesman with the goal of bringing in full-time results. I gathered my workers and told them my decision and requested their help in my endeavour. They were thrilled because for the first time they knew an engineer was selling their stuff and they had confidence in me.I had no formal sales experience -- so I quickly learnt the ropes of that aspect. In the next part of this section, we will concentrate on that portion -- namely, what does a thermal spray salesman need besides knowledge of the business?

In this section, we will address the basic characteristics that a thermal spray salesman and for that matter any salesman must develop. First of all, you need to be positive and optimistic all the time -- a salesman that predicts loom and doom and is always pessimistic will bring in no work -- period. Next, sales is a numbers game -- you must be willing to make cold calls everyday -- the more new people you contact, the more are the chances of getting a sale. Next, take care of the customers you already have -- all existing customers must be contacted periodically with the critical ones being paid a personal visit also. Next, take all companies that have purchased from you in the past several years but have stopped buying from you and call them to find out why and what can be done to earn their business back. I have personally experienced this exercise and believe me it works. Many times, they may have switched suppliers for silly reasons. A salesman must have high levels of motivation. There are many wonderful sales motivation books, tapes, seminars and the like -- find out a good one and invest in it -- the returns could be severalfold. In my sales experience, I would wake up everyday at 4:00 am, and develop my sales administration till 7:00 am and then go to work with a full plan for that day. It paid off very well for me. This included writing follow-up letters, writing down contact info for new contacts and the like.
Next, get some standard 1" panel samples coated with various coatings -- that should be the only "free" samples that you hand out. I do not believe in coating customer parts for free as evaluation samples -- those end up in some engineer's desk collecting dust. All customer parts -- even those deemed as test parts -- must have an invoice value -- even if it is only nominal. In a future post, we will delve into developing coating designations for repeat business development.

Thermal Spray Story - Contd

2008-03-21T12:20:00.000-07:00

In continuation with a previous post on thermal spray story, I would like to discuss about a pitiful situation that exists in several substandard thermal spray coatings shops around the world -- be it thermal spray shops in China, thermal spray in Japan, thermal spray coating shops in India, flame spray coating companies in Europe or the plasma spray companies in Americas -- I am using the word "substandard" from a business performance stand-point -- not from a technical standpoint. What I quickly learnt was that first of all we needed to look at our shop as a business and not a hobby. So, firstly, I re-assigned the janitor we had to become a grit blaster helper and masker helper. It became everybody's job to keep their own area clean. Next, we had a couple of " certified " spray operators who could pretty much dictate the terms of how the business ran. They were the primadonnas -- I am sure if you look around, your shop has such people too. It was the first Friday in my new position, and we had to coat 500 pieces of a certain component with tungsten-carbide-cobalt, to be shipped on Monday. The spray operator said that at 3'O clock his shift ended for the week and that he ain't working the weekend. I thought to myself -- "No wonder we aint getting anywhere in this shop." That evening, I said "every person in this shop including engineers, managers, maskers and blasters will have to become certified operators." And conversely, every sprayer will mask his own parts and girt blast his own parts if necessary. Needless to say, it didn't go too well in the beginning -- but suddenly, we learnt that the best way to have job security is to be able to do everything -- not just one thing.
This concept of "cross-training" which is quite commonly spoken about but seldom practised, is the first and foremost step to be taken if your thermal spray shop needs to be successful. I have come across quality control inspectors who had no idea of how the thermal spray process worked and engineers that have never held a plasma torch in their hands ! And yet these were the people writing process sheets and determining product acceptance!
Add to this the finger-pointing and blame-assignments and you have a perfect mess -- I have seen sprayers complain about maskers and maskers complain about process sheets that are senseless at best and meaningless at worst -- and yet we were tasked with getting more customers and becoming profitable -- does this sound familiar? Me fellow thermal spray colleagues -- I have felt your pain many times before ! ( LOL ) Then came the salesmen -- in white shirts and red ties -- these guys could not spell the word tungsten carbide or aluminum, thought six-sigma was some kind of fraternity -- and yet we were dependant on these smarties to talk intelligently to potential customers and get us business !
This is the pitiful situation that we started this article with.I cannot wait to write my next article -- we need to get the frustrations out first before we can fix them !! See you soon!

Thermal Spray Story - 1

2008-03-21T11:09:00.000-07:00

I have developed this blog regarding the thermal spray coating business directed towards the business person that either owns a thermal spray coatings shop performing plasma spray, hvof, twin-wire-arc or other flame spray coatings or is thinking about getting into the thermal spray coatings business. This may also be of value to those professionals in the plasma spray coatings and thermal spray coatings field that are interested in expanding their revenues in the field of thermal spray technology. This site also deals with the practical but significant details of the thermal spray engineering, quality and processing aspects. The idea to write this came to me very recently, as I was reminiscing about my past -- I was a young engineer working with professionals in thermal spray and I always heard the big bosses talking about ways to increase business -- some of which were brilliant ( and conversely, some of which were not so bright.) Several years later, I went over to the really BIG BOSS one day and told him that I wanted to move from engineering to managing a thermal spray division. He said NO. He probably thought that since I was a smart engineer, I was only a technocrat and not a business major and hence could not "handle" the business aspects. So I quit and found someone who offered me exactly what I wanted -- running a coatings company -- except this was a losing business -- we could barely meet our payroll ! There was poor morale among the existing employees -- most of the hourly workers were getting sent home early on "LOW" -- that stood for lack of work -- ( in retrospect, I think the managers should have received that honor ! ). But the shop looked great -- pristine, clean and with a young man that was given the janitorial duties. He, by the way, was also putting in less than 40 hours per week ! The employees didn't know when the axe would come down and they would lose their jobs. And I thought to myself, "what a FOOL I had been to have quit engineering and come to this !" Engineering was simple -- it was about solving problems using physics, mathematics and chemistry. The situation I got into had no simple pathways to solutions -- at least none that I had been exposed to. However, I was not willing to give up. What started out as a brilliant engineering career, then turned out to be a brilliant management career and what I learnt from those many many years I feel would be of value to others in similar situations ! In this blog I have tried to cover both the technology of thermal spray as well as the business aspects of the process; after all, if you dont make any money, your company ceases to exist.

Thermal Spray Estimating | Quality

2008-03-19T14:09:00.000-07:00

In a previous post, I had mentioned that quality control in thermal spray businesses starts off right at the quotation stage when you are pricing and estimating jobs and submitting quotes to your customer. There are several estimating and quotes software programs available in the market today. These estimating programs take into account the variables such as material costs, labor costs, overheads etc and come up with estimating data for quoting purposes. Let us examine this quoting and estimating process in a little bit of detail from a quality stand-point as it applies to the thermal spray coatings business.

I strongly feel that a check-list should be made available to the estimator when quoting jobs. Regardless of how experienced the person is, a check-list is always helpful. This is similar to the pre-flight checklist that airplane pilots use regardless of how many thousands of hours they have logged in. Remember, we are dealing here in this post with only the quality aspect and not the business aspect of the estimating process. The first and foremost is the coating material – is the correct thermal spray powder or thermal spray wire being considered; the correct class of the thermal spray powder and the correct sieve size needs to be considered to meet the correct customer specifications. I have come across situations where assumptions were made as to the class of the thermal spray powder and the cost of these powders can vary quite a bit and you end up with a losing contract or you lose the contract because the incorrect estimate was given and the price was too high. Are the correct masking requirements being taken into consideration. Masking is quite labor intensive and this could either affect pricing, delivery or both quite a bit. Are the correct quality control requirements being taken into consideration – many times, the customer will require an independent lab report to be submitted with every lot of parts – this costs money; sometimes, reduced metallurgical testing frequencies may be allowed – these have to be taken into consideration. What about process planning sheets – if they have to be approved by the customer before work can begin then the quotation needs to reflect the associated costs and timing requirements accordingly. There may be other quality control requirements such as submission of technical plans and customer review of first article processing and so on; these requirements must be reviewed by the estimator before submitting the thermal spray coating service estimate. Believe it or not, some companies require elaborate packing requirements during shipping – have they been considered or overlooked.

As discussed, quality checklists during the estimating and quoting stage can be very helpful in thermal spray coating shops. Being essentially a special process with intricate quality requirements, special care must be exerted during the stage of quoting and estimating and then of course after all the considerations have been made, one can use off the shelf quoting and estimating software if they prefer.

Software Quality Control

2008-03-17T13:13:00.000-07:00

Software Quality Control in thermal spray shops is highly overlooked. Whereas in many manufacturing environments such as cnc machining services, etc software quality control has become a way of life, thermal spray shops seem to be spending very little attention to this area, although it can make a significant difference in product quality assurance.

Many thermal spray shops have robotic spray booths with individualized programs for thermal spraying of specific part numbers. It is essential first of all to have a procedure written for robotic program development – otherwise the first engineer writes code in one way and then he quits and the next engineer that takes over has no clue as to what the first engineer wrote and so on. To avoid this waste of time and money, specific code writing procedures need to be in place. Some of the older robotic code is written in machine language as opposed to Pascal or C, making this “other persons’ code” understanding bit more difficult. Programs need to have plenty of comment statements regarding robotic moves as well as instructions regarding setup points relative to part being thermal sprayed.

Additionally, proper revision control on all robotic software programs need to be under engineering control. Many companies put in the robotic program printout itself on the shop floor process sheets. In such cases, when the robotic program is revised, so should the process sheet; otherwise the process sheet will not reflect the actual operation on the thermal spray manufacturing floor. Software quality control and software quality assurance is an essential part of the QC function and must be implemented in your thermal spray shop even if you have only one robotic cell.

Quality Control and Assurance

2008-03-15T13:29:00.000-07:00

In the next few posts, we will be discussing the quality control and quality assurance aspects of thermal spray coatings. While there are several academic treatises on this subject, we will be concentrating more on the practical aspects of running a high quality thermal spray coatings operation with customer satisfaction being the end result. A good quality control manual, good quality control testing practices, good easily retrievable record keeping, good maintenance practices, etc all go into producing good product quality. If you are or planning to get into the aerospace coatings business, then there is NADCAP which is the National Aerospace and Defense Contractors Accreditation Program which has stringent quality systems requirements to be met; automotive quality systems have their own requirements and of course the ISO requirements are quite involved also. In any case, once you develop a strong quality control organization, systems, procedures and implementation, you should technically be able to meet all of the requirements of quality control and quality assurance.

While there are several templates available by third party companies for developing quality control manuals and the like, the best way is to write your quality control manual from scratch that is specifically written for your organization and way of doing things. One Quality Control manager once told me “My job is simple – I have to say what I will do and then do what I said will do !” The problem with smaller thermal spray shops is that they lack personnel to fully support the Quality Control function. They somehow need to address this issue. Nowadays, customers may have specifications for coatings requirements that have to be met; someone needs to keep up with these specifications, changes to specs, revision levels, etc and ensure that the proper specifications are referenced in the process operation sheets. Without all these quality controls and systems in place, the wrong coating may get applied to the wrong part, or the incorrect thickness of coating or metallurgical test standards may end up getting used. While this seems hard to believe, I have seen these things happen in real life; especially when it is the same coating but a different class – Metco 101NS versus Metco 101BNS.

Really, quality control starts with the quotation stage and ends with shipping. The financial aspects of accounts receivables are not really included in the quality control process even though they should really be. For instance, I know of a case where an accounts receivable clerk kept calling and sending reminder notices to the customer for past due invoices when in all actuality, the invoices were all paid up to date and it was actually an error in inputting the receivables data on her part ! We will deal with as many aspects of quality control and assurance in the coming few posts as we can, and hopefully this may be of value to you in addressing some of the quality control issues in your own shop. Remember the ultimate goal is to develop a sense of complete satisfaction on the part of the customer that he received a good quality part in the promised delivery time at a reasonable cost. Of course, there is a certain cost to quality – the higher the quality demands, the higher the cost; rejected parts and re-work costs cost money and should be minimized as much as possible.

HVOF Thermal Spray

2008-03-10T14:08:00.000-07:00

HVOF stands for High-Velocity-Oxy-Fuel. The HVOF thermal spray process was originally invented in the hopes of finding an alternative to the Detonation Gun process. In this process, combustion takes place between oxygen and a fuel gas such as hydrogen, similar to the simple combustion guns, except that additionally, the velocity is highly accelerated. Thus the coating powder particles get both thermal energy as well as kinetic energy. One can visully see diamond patterns in the flame indicating the supersonic speed of the process. Powder particles are usually injected through the gun and form high quality coatings. To prevent coating build-up in the gun, thermal spray engineers have used some tricks such as changing the cooling water flows and directions. HVOF thermal spray produces dense microstructures and is very suitable to coat materials such as tungsten-carbide-cobalt, Cobalt-molybdenum,Chromium, silicon ( commonly known as T-800 ). It has also been very successfully used in re-building of mis-machined surfaces using inconel. Cobalt-Nickel-Chrome-Aluminum-Yttrium (CoNiCrAlY) deposits formed by HVOF thermal spray process using certain parameters have produced LPPS quality coatings as far as oxides and porosity are concerned. This is of course, a succint description of the HVOF process.

Major Applications

2007-12-25T09:42:00.000-08:00

Thermal sprayed Coatings have numerous applications to cover in one paragraph or one page. This article might provide an insight to many engineers in other fields to potentially use thermalsprayedcoatings in their applications to solve problems; it might also clue in to current thermal spray applications engineers to bring in new business to their companies.
Thermal Barrier Coatings:Thermal barrier coatings or TBCs as they are shortly called form a barrier as their name indicates to the flow and transfer of heat. This is used widely in aerospace applications in burner cans, combustion chamber cowls and domes, nozzles, etc. Generally, the combination is NiCrAlY as bond-coat and yttria-stabilized-zirconia (YSZ) as the top coat. Several variations are used including magnesium zirconate as the top coat or varied levels of yttria in the YSZ. There have also been graded coatings where a transition middle layer is used between the bond coat and the top coat. Bond coat thicknesses are usually .004"-.008" and top coat thicknesses are usually .010"-.014" in TBC systems. TBCs have also been used in power generation transition pieces where the coatings are deposited in the internal surfaces to redirect the heat to the inside and prevent the transfer to the outer casing. Industrial furnace components have been coated with TBCs as well as some high end components for space travel applications.
Abradable Coatings:
Abradable coatings as the name implies are for instances where the coating is designed to be cut into such as the case of aeroengine hot section abradables -- CoNiCrAly coatings formed by the LPPS process or lately with the HVOF process are used in hot sections. Used for clearance control, these coatings can be deposited to high thicknesses. Plasma sprayed nickel-graphite has been used for decades in certain applications. Aluminum-polyester coatings deposited by the plasma spray process is another alternative -- an example is by the use of powders such as Metco 601NS. In jet engine compressor cases, aluminum-silicon has been used very successfully. The porosity levels as well as porosity distribution in the latter two are very critical to abradability. Metallurgical lab evaluation of these coatings is extremely sensitive to pull-outs during polishing and special attention needs to be paid.
Abrasive Seal Coatings:
Aluminum oxide is the most common material used in abrasive seal coatings used in the aerospace industry. Knife edge seals have been coated with alumina-titania coatings for decades for this application. Usually, the combination is a nickel-aluminum bond coat of about .002"-.004" followed by a .008"-.012" top coat of alumina-titania. Key to coating knife edge seals is the uniform deposition of the coatings -- robotic application provides the best quality. These knife edge seal coatings can be stripped and re-coated -- we will be addressing stripping techniques in a different article.
Sealed coatings:
Many thermal spray applications involve first depositing the thermalsprayed coating and then infiltrating it with special sealants. For example, in a paper converting application, you can simply coat using Nickel-Chrome-Aluminum ( such as Metco 443 NS ) and then infiltrate using a Ultra-violet cured silicone for release properties ( UV coating ). The plasma coating holds the otherwise weak UV silicone coating. There are other sealants that can be infiltrated also. This is heavily used in the paper converting and printing press applications.

Other T/S processes

2007-12-07T00:12:00.000-08:00

Simple Combustion Process:
In the simple combustion process, energy is generated by the combustion between oxygen and a combustible gas such as propane inside a torch and the powder is fed through a powder port and the resulting coating deposited on to a substrate material. This process has been used to deposit abradable materials such as nickel-graphite and the like. Very high thicknesses of nickel-graphite have been successfully deposited using this process. This has been the forerunner to the now-popular HVOF process. The Metco 6P torch has been used for several decades to accomplish this type of coating. As a sidenote, in depositing nickel-graphite coatings, powder settling becomes a major problem -- powders must be properly blended and kept hot so they will flow easily and form uniform microstructures.
Low Pressure Plasma Spray:
In the LPPS method, coating is accomplished in a vacuum chamber -- this therefore results in oxide levels in low-pressure plasma sprayed coatings to be very low. This has been successfully used in developing thick Co-NiCrAlY coatings, titanium-6Al-4V dental implant coatings as well as some high quality titanium-carbide coatings. Key to watch out for is to also check leak-up rates in the powder feed system, since that can cause leak-contamination in the vacuum chamber.
Simple Wire Gun Process:
Unlike the twin wire-arc process, here there is only one wire involved. Used extensively in aluminizing applications, this has been used for decades successully with a post diffusion heat treatment.

Twin-Wire-Arc process

2007-12-06T00:12:00.000-08:00

The twin-wire-arc process of thermal spray is actually a fairly well-established process, wherein two wires are fed through and an electric arc struck between them. This melts the wire and a carrier gas "shoots" the melted particles on-to the substrate material to be coated. It has been used for several decades to re-build worn out surfaces on pump components, etc. Nickel-aluminum wire is the most common. However, there have been several applications where cored wires that comprise of harder core materials such as tungsten carbide particles encapsulated in a wire have been used. The TAFA MX-C series of wires fall under this category. Years ago, there was a wonderful application, wherein the wire arc process was used as a low-cost replacement to developing a hard wear resistant surface on to barrel bars used in the corn oil extraction industry where the previous method was PTA ( Plasma Tungsten Arc ) welding. Again, for sensitive applications, proper control of the wire feed rates, stand-off distance, and current/voltage parameters are needed for superior coating quality.

Plasma Spray Process

2007-12-05T00:12:00.000-08:00

In the plasma spray coating process, a plasma plume is created by striking an arc between an anode and a cathode with gas flowing through. The arc rips off electrons from the primary gas flowing through making it highly unstable; its natural tendency is to replace the lost electrons and thus come back to its stable state. This distance can vary quite a bit depending upon the voltage, amperage as well as the properties of the gas used. Generally this is about 4 inches. A coating material in the form of a powder is fed into this plasma plume; the material gets highly energized and reaches a plastic state and reaches the substrate where it bonds to form the coating. This is the succint description of the process.
As one can deduce, if the pressure of the surrounding "atmosphere" is lowered, then the length of the plasma plume increases; this is the case in low-pressure-plasma-spray coating process, where the plasma is generated under reduced pressure conditions. The length of the plasma plume in such cases can be as high as 14 inches. If metallic coating materials are used, then they are prone to oxidation by the surrounding air. The level of oxidation can be controlled either by coating under low-pressure ( sometimes referred to as 'vacuum plasma' ) or under a shroud of inert gas such as argon, referred to as 'shrouded plasma'.
The primary gas used for standard air plasma sprayed coatings is generally nitrogen or agon. In most cases, a secondary gas is introduced into the stream to enhance the energy level. This gas, usually referred to as the secondary gas, is either hydrogen or helium. Hence the gas flow is either a nitrogen-hydrogen or argon-helium combination.
Proper introduction of the powder into the plasma plume is critical to coating quality. Improper introduction of the powder will result in unmelted particles in the coating aggregate. The powder is usually fed by a powder feeder with a carrier gas at a predetermined feed rate that is usually closely controlled. Too high a feedrate will also cause bad coating quality since the particles will not have sufficient energy.
There are several variations to gun/substrate movement -- the common methods being (a) the substrate to be coated is either held stationary and the plasma gun is moved relative to it either manually or attached to a mechansim such as a robot arm; OR (b) the substrate is installed on to a turntable and the plasma gun is moved in an up-down manner. In all instances, proper speeds for the moving equipment is important to ensure uniform high quality deposition. For example, turn-table rpm, traverse speeds (inches/minute), etc are critical. In more critical applications, advanced controls to turn off the powder feeder and the gun if the turntable stops, etc, can be instituted.
For safety aspects of the process, you may want to visit my page http://safetyfirstatwork.blogspot.com/.

Thermal spray what's it

2007-12-04T00:12:00.000-08:00

This site is devoted to the understanding of thermal spray coatings technology. We will be addressing several topics in this site that we presume will be useful both to those intending to learn a little bit more about the thermal spray process prior to using it in an application as well as to those professionals in other engineering fields that might be able to solve future application problems using thermal spray technology. It might be of value to refer to the archives for any specific topic of interest. For safety aspects of the process, you may want to visit my page http://safetyfirstatwork.blogspot.com Being essentially a surface modification process, thermal spray coatings consist of applying a variety of coating materials by elevating the thermal energy of the coating materials and sometimes the kinetic energy of the coating materials and bonding them on to the substrate material. Unlike some other methods of coatings deposition, thermal spray techniques allow a wide variety of coating such as metallics, intermetallics, ceramics and cermets to be deposited on to a wide variety of substrate materials such as metals and non-metals.
In our next topic of discussion, we will discuss plasma sprayed coating process as the one method of imparting energy to enable the bonding of coating material to the substrate material.