From what I read on the framebuilder sites, I think decals and clearcoat are usually done wet even over a powdercoat color layer. There are some decals that withstand high temps, but it's limiting. A poly clear coat is pretty robust in my experience. I painted my tandem with lacquer and then did a polyurethane clear. It held up to almost everything I've thrown at it, unfortunately I had to do some brazing on it so it needs a new paintjob.