frickstyle

I have a pair of used Stainless Marine manifolds that I would like to re-coat. I attempted to blast them in my parts booth this morning, only 110psi. What is the best method to remove the existing powder-coat?

I was advised to obtain some aircraft stripper, soak, scrape off old coating, rinse, re-blast, then send to powder coating. Anyone have a success story they would like to share? Thanks!

-JFrick

86Capri

I found best to just use a grinder or like 80 grit and sand through. We did the stripper also the coating came off in different areas. Over all we ended up sanding then blasting for the little stuff.

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heavanie

The jacket on the SM manifolds is thinner by design. It is meant to leak before the manifold itself in the event of corrosion. This design let's you see the problem before it ruins your engine. I own a powder coating shop and have the same exhaust on my python. I would recommend a couple of rounds of stripper before grinding of any sort. Any amount of material removed will shorten the life of the exhaust. After stripping, light media blasting to give the material a profile and powder coating or painting (whichever you prefer) is the way to go. Be glad to answer any other questions you may have. Good luck.

frickstyle

Thanks guys, I will try to sand before using any chemical stripper. I prefer not to use any chemicals.

downtime270

Hold off before you go crazy....I'm in the metal finishing industry and apply powder coatings as well as a number of other high end (aerospace) coatings and platings. As far as powder goes there are typically two types; thermoset and thermoplastic. Thermoset is a one shot deal and will not "melt" again. Thermoplastic is re-meltable and will flow again. Take a heat gun and put it on a spot. You need to hit around 350 deg. F. If the coating softens and "flows" its thermoplastic. If it does not its thermoset. Whats nice is you have a couple of different options depending on the type of powder. If its thermoplastic, you can use some 80g sand paper, scuff the surface and then re-coat, but you have to make sure you get a good ground for the re-coat process. Since its thermo plastic, the basecoat will melt again and will provide for a good bonded surface. If its thermoset - we have had good luck just abrasive blasting the material to remove the glossy surface, leaving the powder layer still adhering to the substrate - then recoating right over it...No need to strip to bare metal. Remember if you have good adhesion to the substrate its half the battle - the powders typically stick well to themselves... Let me know if you have any other questions...Good Luck!

frickstyle

Great, thanks. All good info here. I will proceed with caution.......