Repairing Fiberglass Boats

Fiberglass is a material made from fine threads of glass. This mixture of plastic and glass is considered a durable material. It is used for a number of objects such as boat hull because of its durability and its lightweight characteristic.

Fiberglass hulls can get damaged, particularly when traveling on rough water or rocky beaches. You can choose to have the hole accessed and repaired by a professional or repair it yourself.

The following are materials and tools you will need to repair fiberglass boat hull:

  • fiberglass mat;
  • resin and hardener;
  • plastic;
  • cleaning solvents.
  • disk sander;
  • coping saw;
  • roller; and
  • protective gear (mask, gloves and protective clothing)

Use a respirator or dust mask designed for work with fiberglass. Fumes and dust particles are generated during the repair process. You should also wear gloves and protective clothing to prevent cuts and scrapes.


Steps in Repairing Fiberglass Boats


Locate the damage. There may be some problems with access to the hole or tear, especially when it is located on the boat floor. You may need to move some equipment or stored items to gain access to it.

Cut away the damaged part and the surrounding area using a coping saw. You should be left with a circle or oval to work with. If the broken area has been delaminated, tap the area with the end of a screwdriver to gauge the extent of damage. Solid laminate sounds sharp, while broken laminate sounds dull. Remove and replace all damaged fiberglass.

Clean the site before repairing. Fiberglass resin sticks best to a clean surface. Be sure to dry the area after cleaning.

For damages which are small and above the waterline, you can repair it from the inside. It is preferable to work from the inside because you will use less resin and less finishing work.

De-wax the area before grinding it to avoid mixing wax with grinding residues. Grinding aids the mechanical bonding of the fiberglass layers. Use a disk sander to grind a 12-to-1 slope around the perimeter of the hole inside.

Cut a scrap of smooth plastic laminate or thin clear acrylic a foot larger than the hole. Wax the backer then spray with mold release. Screw or tape this to the outer surface.

Cut the fiberglass to fit the hole. The number of layers will depend on the thickness of the hull. Continue layering up until the repaired surface is even. Check for air bubbles and wrinkles for a good finish.

Cut some fiberglass mat and cloth. Apply them over the patch. Smooth it with a roller. Plastic can be used to seal the layer until it is cured.

Remove the backer from the surface. Clean the area and polish it.

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