Originally Posted by LGM Graphix

You can spray direct onto prepped Gel coat, sand the gel coat with no finer than 600 grit wet. I still prefer to sand it out with 220 and spray a coat of catalyzed primer though and then prep the primer to ensure no imperfections are left before painting. Allows you to take care of seams as well that way. If you do want to spray direct onto the gel coat rather than spray a high build primer I highly recommend spraying a coat of epoxy primer followed by your first color coat in a "wet on wet" application. Spray the epoxy, give it 20 minutes to flash and immediately spray your first base coat.