I'm cleaning and painting my A-4. My tactic has been to disassemble, scrape, wire brush, naval jelly, and then use Rustoleum Rust Reformer before priming and painting.The primer and paint I'm using is high temp (500F) ceramic paint that I puchaced from Napa. They even have a high temp top coat called Universal Gold!
On a whim, after Rustoleum Reforming the rusty head and exhaust manifold, I called Rustoleum and asked to speak with a techie. He said that the stuff will flake off at 212 degrees. I had already applied the top coat several days before, but I said what the heck, and I put the exhuast manifold into a 400 degree oven to check it out.
After an hour, some of the ceramic paint had bubbled in places, but the Rust Refomer seems sound.....
Anybody have any ideas about this?