How To Prep a Boat for Painting

Welcome to our shop and Matsya, our 1938 Herreshoff Marlin. Today I'll show you how to prep the trouble spots on her topsides that are bare paint and peeling paint.

Editor's Note: Though the hull in this video is wood, the process is the same to prepare old gelcoat on fiberglass topsides for painting.

First I like to inspect the whole hull looking for the trouble spots. I mark the trouble spots with a piece of tape. That way they're easy to find when I go back to take care of them.

Once I've found the trouble spots, I like to go with a flat putty knife and remove all the peeling paint. Only remove what is not adhered well to the hull.

Now that we've scraped off the loose paint we need to sand and feather in the edges. Some of the areas will be deeper than we can feather in; we'll have to do a fill. But before we do that, we want to sand and feather the edges, and then put primer over the bare spots.

With the edges faired in, the bare spots smooth, and the few deep spots we'll have to fill, we can tack rag and prepare the surface for primer.

Let's apply the primer. You don't have to go thick; just do a nice job covering the surface.

Our primer has dried. It's time to fill the low spots. I've mixed up a little bit of epoxy with a sanding filler, and I'm applying that. And then with a nice putty knife, smooth it out. Don't overwork it; let it cure.

Our filler has cured. Now we lightly sand the edges. It won't take much.

Tack rag the surface once again, and apply the final coat of primer over the filled surfaces.

Let the primer dry, and her topsides are ready for prep and painting.

For more tips on painting decks, and on getting good painting results in general, read 10 Tips on How to Paint a Nonskid Deck or watch How to Paint a Nonskid Deck.

Written by: Paul Cronin

Paul Cronin is a lifelong sailor who has turned his passion for boats and photography into a career. View more photos and videos of boats, the marine industry, and the world around us at his website.