How to Patch a Fiberglass Canoe

Fiberglass is a very strong and durable material, but even fiberglass is vulnerable to failure. Common failures in fiberglass are cracks or small holes. Fiberglass canoes are exposed to rocks and rough waters, which can cause cracks or holes to occur. Canoes can be very expensive to replace if a failure occurs. A cheaper route to take would be to patch the canoe yourself, which is considerably cheaper than buying a new canoe.

Things You'll Need

  • Air compressor
  • Air hose
  • Respirator
  • Dye grinder
  • Palm sander
  • Fine grit sandpaper
  • Rags
  • Acetone
  • Marine fiberglass filler
  • Methyl ethyl ketone peroxide (hardener)
  • Putty knife
  • Gel coat
  • Felt roller
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Instructions

    • 1

      Plug the air compressor in and let it build up air pressure. Connect the air hose.

    • 2

      Wearing a respirator, grind the fracture using a dye grinder. Grind out the middle of the fracture, forming a groove in the fiberglass. Grind the groove as deep as possible without going all the way through the fiberglass. Gradually taper the walls of the groove. The more gradual the taper, the better the bond will be.

    • 3

      Clean the repair surface using a rag and acetone. Remove any grease or dust that remains on the surface. Grease or oil can cause the fiberglass to poorly bond together.

    • 4

      Mix the fiberglass filler and the hardener as directed on the containers. Use a small bucket and stir stick to thoroughly mix the filler. When the filler turns into one color, apply it to the fracture. Use a putty knife to smooth the filler out so that it's level with the surrounding fiberglass. Let the filler harden.

    • 5

      Sand the filler using fine grit sandpaper until all the burs are removed and the filler is smooth. Use the palm sander for an even and speedier sanding.

    • 6

      Mix the color-matched gel coat with the hardener as directed on the containers. Apply the gel coat to the repair using a felt roller and let dry until hard and cool to the touch.