Got some new finned Aluminum valve covers and I'm looking to color paint the valley areas between the fins to match the car color (gold). They are new, do I need any special prep, primer or paint for high heat other than brush on engine enamel?
You should provide some "tooth" for the paint to adhere effectively, either by chemical or mechanical abrasive means. If it was me, I would just tape off anything not being painted and lightly sandblast or just sand, then making sure the surfaces are clean. I usually wipe down with acetone following up with a tack rag. Paint or prime and paint following the paint manufacturers recommendations.
I have done a couple sets without any sanding or blasting just cleaned with lacquer thinner and the paint was still there 10-12 years later when the car got sold. No special paint either just from a spray bomb.
What they said... And... Don't brush them, spray them. A lot of people use two-part epoxy paint on engines to hold up to the high temperatures, but valve covers aren't nearly as critical. Like loudbang said, spray bomb paint will work fine. Tape off the outer perimeter of the area of you're painting. Paint everything. Have a rag handy to wipe the paint off the top edge of the fins. Have another rag ready, very slightly damp with paint thinner to wipe off the last of the paint residue. Have fun. Sent from my VS835 using The H.A.M.B. mobile app
More details are needed. Are the VCs as cast or are they polished? Are you planning to paint just the 'valleys' between the fins at the top or are you painting all around the sides also? The bare minimum would be to de-fingerprint and degrease with solvent. If you are simply painting the spaces between the fins, the color should be protected to a large degree from getting bumped and chipped.
I just cleaned my aluminum valve covers with lacquer thinner and then used regular red spray paint on them (the same paint I used on the block) I let then sit for a while and get tacky, I then wrapped a piece of cloth around my finger dipped it in lacquer thinner and slowly wiped the red off the top of the fins. It worked great. HRP
Hey Danny, don't mean to hyjack the thread, but where did you find the invisible plug wires, I've been looking for a set!
Best prep beside a good cleaning for aluminum to get paint to stick is Zinc Chromate primer, I am not sure that it is readily available but zinc oxide primer will also work in a pinch.
Clean them, then when they're clean, clean them again. Red scotchbrite pad to scuff them, clean them 2 more times. If you're worried about adhesion, buy you a can of bulldog adhesion promoter. Spray a light coat on, wait 10 minutes, spray another coat on, wait 5 minutes and paint them.
I still find it in rattle cans at Ace hardware but someone said its hard to get in some places. It is what we used to use to get paint to stick to motorcycle crank cases when that was popular. The only prep necessary was to get them clean. it is considered to be a self etching primer and is sometimes sold as a self etching primer.
I had mine polished by a local company and told them to ignore the area between the fins. Wiped the area down with acetone and spent a long time masking. Sprayed them with Buick engine paint.
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