Have any of you airbrushers out there tried the Water Based Paints from auto air? I was curious about clearcoating over them. I would assume you need to clear coat over with a good quality eurothane right? Any problems with that? I ordered a set and plan on trying them out on our helmets for racing and practicing on some scrap metal until I figure them out. The how to's on the auto air site look just too easy. Can it be true?