To paint a fiberglass boat remove any parts of hardware that you do not want painted. Use a clean cloth to wipe the boat down with a wax removing solvent. Look for any scrapes, dings or gouges on the boat’s surface that need repair. Fill these areas with an epoxy filler and allow to dry. Sand the filler down using sand paper and a dual action sander. Apply a thin coat of primer to the boat’s surface with a roller or brush. Cover the entire area of the boat that will be painted. Paint the boat with the 2-part urethane paint.