Re: Exhaust And Thermal Coatings?
Part of the reason I started this thread and mentioned that I was not interested in coatings from Techline, N.I.C. or others that are water / solvent based "spray on paint type" or the the shiny "looks like chrome" coatings is because as a Techline coatings applicator who use to and still from time to time use N.I.C., I can tell you that:
A. Currently with the chemistry and technoligy widely available at this time in the market place, the above type coatings if subjected to hi performance turbo temps., either won't look good / last very long or will fail out right very quickly.
Or
B. Will look / last ok with a moderate / richer (read lower exhaust temp.) tune, until you start to push it and the exhaust temp. goes "Hi Preformance".
Colored (other than the natural black, various shades of grays and white / off white) and the chrome look coatings are pigmented and will burn if subjected to the average temps when "pushing a turbo set up". Now many of the companies will say I am wrong for many reasons etc, etc. As several folks here commented on another thread, you can take it from the builder / applicator with experience or the salesman / company pushing the product. Jet Hot, H.P.C. and every other company that will be straight and upfront will tell you the same thing. The colors and chrome stuff are good to great for N.A. and low tune performance engines, not performance turbo (for sure not high performance turbo), high performance blower or max effort N.O.S. applications.
Look at the major race teams and what they are using including the Indy cars? Most all are in with some type of 1600 deg.+ black, gray or white natural type coating that is more than 5 to 8 thousands thick (usually applied by furnace spray, wire arc or other molten applied process) because the thin pigment applications fail. Plain and simple, If you have a turbo application and it is a shiny or pigmented coating and it still looks good / has not started delaminating after a long period of use, it's because you haven't pushed your build and you will never know for sure what the actual temp is anyway unless you have an E.G.T. / pyrometer. If one of our customers wants exhaust coatings and he tells me it's turbo'd, blown or heavy N.O.S., I pass on what is available to me that can apply and that is the water / solvent base products. I know because we build a lot of roots and centrifugal blower engine's, most do not have the extra heat associated with a turbo and they just don't stand up long term.
Coating the inside: There are reasons why more than a few of the high end applicators don't or won't coat the inside of anything in front of the turbo unless you request it and then they will tell you that they don't recommend it and there is no warranty for a turbo application, if a piece flakes and damages the turbo. Application requires spotless surface prep just like a good paint job. Put any and I mean any coating on top of a speck of rust, dirt or oily contamination and it will come off, it's just a question of when or how long, not if. Most all high temp coatings demand some type of 70 - 90 deg. abrasive grit blasting for preperation and you can't "gurantee" blasting EVERY bit of the surface of the inside of long or bent section of tube, interior of turbin housings and most but not all manifolds. D/P's are not a problem since most are short and it's after the turbo anyway. Same for non turbo applications, if it does delaminate there is no damage. The ultra high temp / thicker coatings if delaminated are not a fleck of paint. They are 5 to 15 thousands thick raw ceramic or cermaic / alloy blend and do have some weight and strength, try smashing that against a 100,000 rpm turbo wheel. Several of the companies did and Swain Tech will be the first to tell you that they won't coat the inside of anything in front of the turbo because they "don't buy slightly used, damaged turbos" as part of there business. Want the inside coated, take it to another company. That's how strongly Swain feels about it because they have seen it. So have I, but I must admit only once and it was worse than sand . They do it all the time.
I see several comments for Swain, Jet Hot, H.P.C.'s 2000 deg. products and I do appericate it. I honestly wish that Swain had a black or gray coating because I would go with them but they say that their product if colored, even by using the other naturaly colored components would not be as durable as the raw white they have perfected. So it looks like I will be going with Keco Coatings process that they are using for the Indy car applications.
I will post back with photo's and updates as things go, good or bad and I do appericate the info and comments so far. If any one has anything to add I realy would like to hear it and keep the info coming.
Thanks!
__________________
James
