I in the late 80's early 90's I would use spray epoxy paint made to fix stoves and kitchen appliances. It is the only spray paint that ever held up to 40% nitro use with my scratch built hydro and mono boats back then you could only get it in white and cream - I imagine by now you can get other colors two coats and done with proper prep. Sprays smooth and even yet a thicker robust layer then typical enamel paints.