Hello, I want to paint ( spray if poss. ) a roller type garage door and wondered what would be the best paint to use? The door is either steel or aluminium but is coated both sides so not 100% sure! The coating appears to be quite thick and has a slightly rubbery feel to the surface. Not sure if it is pvc coating or chlorinated rubber? I have a portable paint system ( not Graco btw! ) so wanting to know what paint you would recommend to use in the gun? Also for surface prep would it just be a case of washing it ( maybe with sugar soap? ) first then wiping over with panel wipe or an IPA based surface cleaner? Thanks in advance