Aluminum Valve Covers With Clearcoat.....

[Patrick T.]

Thanks for your advice on the sidepipes. Here is another one that's got me. I have an L-79 small block with valve covers which are professionally polished and to the non-corvette person, they look fantastic. However at a recent show I had more than a few comments about the appearance, all bad.

I checked the archives and found a couple good posts regarding "cleaning of aluminum valve covers". One post said the covers should have a "funky dull grey appearance". Having seen several others at the show, I know what he is talking about. Another was using mag wheel cleaner and fine steel wool to clean the covers up.

My problem is after the covers were polished, the vendor apparently sprayed a couple coats of clearcoat on the covers, which is not coming off. These are the original covers and I don't want to screw them up. I tried laquer thinner, but it doesn't seem to cut it. I know the aluminum is delicate, so what would you recommend to remove the clearcoat without damaging the surface of the cover? I'm really stumped on this one. I know I can depend on your advice. Thanks Patrick

[David K.]

Re: Aluminum Valve Covers With Clearcoat.....

When I wanted to return the original finish on the engine cases of my'67 Triumph M/C,I used Zip Strip paint remover.Then I followed that with Castrol Super Clean and scoured them with a non-metalic scouring pad to break the shine.Also this and brass wool, because you are working on aluminum,works great on glass beaded parts that you want to return to there original finish.Another great aluminum cleaner can be found at places that wash down semi-trucks.Make sure you are wearing good gloves,it took me three weeks to feel things that are important to me.

[Redondo Duke NCRS #22045]

Re: Aluminum Valve Covers With Clearcoat.....

Use paint stripper to take off the clear coat, then go to your local PPG automotive paint supplier and buy a bottle of "Alumiprep" and "Alodine". Alumiprep, a mild phosphoric acid solution, will strip the oxide off, and the alodine chromate solution will form an even oxide on the surface giving it a slightly mottled gray patina and prevent further oxidation. These two products are what you use to prepare aluminum for painting, but they can also be used to restore a natural cast aluminum surface. Follow the dilution instructions, and it may take multiple applications of alumiprep to get a uniform appearance. Last year I used this technique to prepare the surface of my Cosworth Vega's cam cover to receive a new coat of flat black paint, and it is indistinguishable from the NOS cover that hangs on my office wall. A week ago I did the cam cover on my '91 MR2 while it was off for a valve lash check and it now has a nice even mottled grey look of aged cast aluminum. If you want, you can skip the alodine and let the aluminum age (oxidize) naturally.

Duke

http://www.gm.com/lemans

[grr]

Re: Aluminum Valve Covers With Clearcoat.....

Patrick, I used to have a stock 1970 LT-1. I had the stock aluminum valve covers also. The way I kept my aluminum valve covers stock look, was the same way I do my 67 side pipes, 1/4" shank drive 3" dia. light wire cir/wheel cleaing w/elect. drill. About twice a year.Try it if all else fails. They looked good and oringal.grr#33570