I did a search, and I can't find anything. I am painting a piece of fiberglass. There's already paint on it from the person I got it it from. It's really small, about a size of a football, so I figured I would just spray paint the thing.

My question is, do I need to spray primier on it? I know I need to sand it down with 30 or 400 grid sandpaper correct? then spray about 3 coats on it, and clear coat. Any sanding in between coats or anything?