Have a friend who just had his valve covers bead blasted. The company who did it is recommending that he spray them with alumablast. Is that a good idea? Are there other coatings to use, or just leave them alone? Thanks Fred
All depends what they look like now. Media blasting with glass beads is too aggressive unless they were oxidized badly. Seymour Alumablast is essentially the same as Eastwoods Tank Tone paint for gas tanks. Not bad choice but a little too bright IMO. Covers in nice original condition should never have glass beads used on them. Walnut shells or plastic media with lower pressure. The original fine cast finish on soft substrate like aluminum is easily and permanently changed. If painting the valve covers is necessary, I'd use Krylon 1403 Dull Aluminum. This paint is outstanding both in restoring a natural aluminum appearance an it sprays well, covers well and is durable. Note the tops of ribs should be more polished looking so smooth them out with scotchbright pad or 600 grit paper, lightly polish and don't paint those or simply wipe it off after painting. Not a highly polished appearance, just brighter than the rest because the natural cast finish was machined off.
DON"T try to powder coat them. The old oils in the porous aluminum will outgas and they will look like they have chicken pox. Voice of experience.
I got a used Edelbrock aluminum manifold and used glass beading to clean it. I then took it to a friend who has a body shop and had him clear coat it with regular urethane clear. I blocked the heat crossovers when installing it. It still looks great after 5 years, no peeling, discoloring or any other problems. To clean just use mild cleaners like you would use on the body of the car.
