CAM COVERS GOING FOR POWDER COATING
12-05-2011, 05:01 PM
#18
928 Engine Re-Re-Rebuild Specialist
Rennlist Member
Rennlist Member
Use a wrinkle powdercoat. I have had a couple sets done, and no matter how hard you try to get them to bake/outgas them before the powder application, they always end up with fisheyes when using a gloss. Wrinkle or any of the "vein" or "hammertone" typed textured coatings seem to work best, especially when stripping the original material. The later the valvecover, the higher quality casting. There are some 1/16" deep pock marks and scars in the early covers just hiding under a thick layer of primer.
12-05-2011, 05:33 PM
#20
Drifting
Some of those flaws, even the nasty looking ones are from the poor casting. As already stated, the casting quality improved as years went on. What did the powder coating place say about the results? One of the reasons to strip the parts yourself is that it allows you to see what's underneath and then you can take actions to correct the flaws before the parts get coated. What do you plan to do now?
12-05-2011, 06:03 PM
#22
Drifting
Eastwood makes a powder coat stripper that's probably safe for magnesium.
http://www.eastwood.com/ew-powdercoa...ver-quart.html
For the casting flaws on the surface, sand them as best as you can to get them smooth and eliminate the high spots. Then use this filler that's safe for powder coating temps.
http://www.alvinproducts.com/Products/Products.asp?id=2
At present, your valve covers don't look that bad when you consider how bad the castings could be.
http://www.eastwood.com/ew-powdercoa...ver-quart.html
For the casting flaws on the surface, sand them as best as you can to get them smooth and eliminate the high spots. Then use this filler that's safe for powder coating temps.
http://www.alvinproducts.com/Products/Products.asp?id=2
At present, your valve covers don't look that bad when you consider how bad the castings could be.
12-05-2011, 06:32 PM
#23
Addict
Rennlist Member
Rennlist Member
I'm surprised that someone would have proceeded to coating those after blasting them. It should have been pretty obvious what was going to happen.
Perhaps another step in the procedure needs to be "inspect (by owner) parts after blasting to be sure that they're properly prepped for coating." Or at least "PCer should consult with owner after blasting if there's any reason to believe that parts will require further prep due to surface imperfections."
It really seems like your PCers should have consulted with you before proceeding to coating.
Sorry that you're going to have to deal with this now.
Perhaps another step in the procedure needs to be "inspect (by owner) parts after blasting to be sure that they're properly prepped for coating." Or at least "PCer should consult with owner after blasting if there's any reason to believe that parts will require further prep due to surface imperfections."
It really seems like your PCers should have consulted with you before proceeding to coating.
Sorry that you're going to have to deal with this now.
12-05-2011, 11:33 PM
#25
The smaller blemishes are the castings. What the he'll
Is that big gash?
Is that big gash?
12-06-2011, 02:02 AM
#27
This is one of my cam covers after soda blasting, it was done inside and out, then chemical washed, the powder coat came out ok using a grey gloss powder coat, not perfect but ok. I'll try to add a picture of the finished cam cover as one still needs to go on the car.
12-06-2011, 09:27 AM
#28
Burning Brakes
The eastwood product is not a safe product to strip the cam covers. You can probably get away with using it once if you're VERY careful. Otherwise the liquid form of the stripper will seap into the pours of the mag and eat the material away. Don't let your parts soak for too long if you use it.
The lab metal product is a good choice to fill in those casting blems.
The lab metal product is a good choice to fill in those casting blems.
12-09-2011, 11:29 AM
#29
Rennlist Member
Thread Starter
eastwood powdre coating stripped
I only bought a small container of the eastwood stripper.
I went to the local big box store and bought a plastic container to soak the parts in.
Came off ok, and the stripper is reusable.
you can really see the imperfections now
should I media blast both sides?
I went to the local big box store and bought a plastic container to soak the parts in.
Came off ok, and the stripper is reusable.
you can really see the imperfections now
should I media blast both sides?
Last edited by PC-85-928S; 02-25-2013 at 01:55 PM.
