ORIGINAL: Hydro Junkie
Ernest, one other thing nobody has metioned yet is to be sure to seal the hull BEFORE you shoot it with primer. Everyone that paints boats in my area seal the hull with epoxy, followed by a thorough sanding. I'm guessing you built it out of wood, so here's the reasoning as to why. Wood grain tends to expand when it's painted, making it show up through the paint. The coat of epoxy prevents the grain from showing through the paint as well as proteting the wood from water seepage if the paint gets scratched off. Just a thought
I have a woodshop and understand a bit about aplying a finish to wood. It's true that the wood expands when a finish is applied...if the finish is waterbase. To avoid the expansion (what happens is tiny fibers of the wood's grain flares up. Good example is the afternoon shadow of a man's face after shaving that morning. To avoid the shadow, wipe the wood down with a damp rag, let it dry. then sand quickly and lightly with about a 300 grit. this will virtually eliminate the shadow! As we say in the woodworking world, try it on scrap first!