PC-85-928S

After having my intake parts and my cam covers, stripped with aluminum oxide media blasting, powdercoated, and reinstalled,
After one day of driving the driver's side cam cover developed a white chaulky toothpaste-like substance on the front of it. The 2 front intake pieces looked like something spilled on them, creating rough drip type spots. The oil filler had one small dime sized rough spot, the center tube was fine, and the 2 rear intake pieces had small affected areas. The air boxes were fine, and the passenger cam cover was ok.
(I can't post pics for some reason now)
I had to remove everything and bring back to powder coater.
He thought something was spilled on them, which was not the case.
I think it is from the underhood heat.
Anyone ever have this problem?

123quattro

I've had a ton of engine parts powder coated. None of them have done anything like that.

Fabio421

Was the powder coat porous? If so, the parts weren't properly cleaned/outgassed before coating. Without pictures it will be hard to say for sure. And the reason you can't post pics is becasue you are a "user" now instead of a member.

Ducman82

did you use brake clean on anything near them? that will do it

PC-85-928S

no chemicals touched them

Ducman82

ya, must be bad prep then. or crapy PC..

BPG_Austin

Pics would be very helpful. could be many things.. Not heat related I wouldn't think. parts are cured at a higher temp than your engine will ever see.. Could be bad powder, (if its silver and wasn't cleared over it could be oxidizing already.. though that would be fast. Metallic pigments in silver are not UV stable and will oxidize if not topcoated. Might ask PCer if he shot a singlestage silver or if he cleared over a non-singlestage like he was supposed to). Could be undercured I guess, but would probably show up with flaking off material instead of the white oxidation you describe. Did you let the parts sit in a waterbath overnight to clean them? That would give you oxidation.. Something bad happened, and unless you soaked the parts in water or spilled a chemical on them, its most likely the coaters fault.
One other thought.. Did you chemical strip all these parts after the 1st PC job, then return them to the coater for reshoot? Was he aware you chemically dipped them before coating? If not, he may not have prepped them to remove the stripping agent and coated over.. Leftover chemical trapped underneath a fresh coat could cause issues for sure. Never seen it though so don't know what it might look like.

PC-85-928S

no chemical stripping
just dry blasting with aluminum oxide.
To be honest, I did not even clean them before installation.

PC-85-928S

pic

Ed Scherer

That'd be my guess.

Sorry this didn't turn out well for you on the first attempt. Must be frustrating as hell.

PC-85-928S

frustrating was when I tried to remove the lower shoulder bolt on the cam cover, to a lovely SNAP
frustrating was when I dropped the Grabbit bolt remover somewhere into my engine, only to retrive it with a magnet on a stick through the drain hole.
frustrating was stripping the top of the intake bolt hole, and having to get a bolt chaser to fix.
frustrating was not being able to get it started to later find out, I had the MAS reversed.
etc etc etc

PC-85-928S

i will win this battle!

robot808

Wait, you had it powdercosted and then installed without cleaning them?

928 at last

A very brave and/or lucky man.......

PC-85-928S

pics