C-3 Refinishing Cast Alum Valve covers

[Bob James]

I have a set of cast alum. valve covers for a 79 L-82. After having them media blasted I found out just how bad the castings are. It apears that GM must have used some type of Epoxy coating on them. Plastic media did remove the lose finish and exposed the pits and voids in the castings. It did not remove all of the coating glass beading will but it is hard on the metal underneath.I plan to talk to my local powder coater and see what he thinks I can do to refinish them but I am looking for any ideas. To fill the voids and pits I thought I'd try JB Weld as it will work in heat ranges up to 300 degrees and then use high temp paint on top. I'd really like to know how these were orginally finished by GM. I know they are GM parts by the part numbers on the inside. I am looking for ideas and information. HELP!

[KEN BUTCHER]

Re: C-3 Refinishing Cast Alum Valve covers

Hey Bob, These aluminum valve covers can be glass beaded without damage, so it sounds like you have very weathered valve covers. But once you clean them up from the bead work, just paint them semi-gloss black high heat and then scrape the fins with a flat blade to remove the excess paint, and you can still get the cross-flag badge from GM. Still remember, nothing was perfect from GM so it's pretty easy to do the job.

good luck.
Ken.

[Bob James]

Re: C-3 Refinishing Cast Alum Valve covers

Thanks for the help. You cannot believe how bad the castings are on these. Their so bad I thought they might be after market but the GM part number is there on the inside. The date code is 1980 it looks like the molds were not hot or the Aluminum was not hot enough to flow into all the mold. I can see why GM painted them black about the only part that is OK is the fins.