On On fiberglass and Kevlar canoes, Scharges performs hull repairs by applying the correct fiberglass or Kevlar patches and resin to the inside of the hull. This restores structural integrity. Then he fixes the gelcoat surface on the outside. You'll also need a fiberglass or Kevlar repair kit. Each kit has the appropriate cloth, resin, resin catalyst, and other items necessary for the repair.
Marine stores sell fiberglass repair kits.
To repair gelcoat, it's best to get a small bottle that matches the color of your canoe from the manufacturer. Start the repair on a fiberglass hull by removing any seats, thwarts, or gunwales that restrict access near the damage. Now you're ready to move to the inside of the hull to make structural repairs. Use paint stripper to remove paint from the interior of the hull at least 6 inches around the damaged area on all sides. Once the paint has been removed, apply a thin second coat of paint stripper, then sand to remove paint left in the weave of the fiberglass.