How to Fix a Surfboard With Silicone

Surfing the waves for recreation or competition can wear out a surfboard. Dings along the surface eventually allow water to enter the foam core, rotting out the surfboard. Fix dings the moment you notice them by cutting out the rot and applying a fiberglass cloth patch, which is made of silicone.

Things You'll Need

  • Plastic knife
  • Mineral spirits
  • Clean rags
  • Masking tape
  • Drill
  • Miniature circular saw blade
  • Plastic container
  • Glass powder spheres
  • Polyester resin
  • Stirring stick
  • Knife
  • Power sander
  • 80-grit sandpaper
  • Epoxy resin
  • Hardener
  • Paint brush
  • Silicone fiberglass cloth
  • 150-grit dry sandpaper
  • 220-grit dry sandpaper
  • Squirt bottle
  • Soapy water
  • 350-grit wet sandpaper
  • 400-grit wet sandpaper
  • Automotive clear coat
  • Polishing compound
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Instructions

    • 1

      Set the surfboard out in the direct sun to soften the wax. Scrape the wax off using the back edge of a plastic knife. Wet a clean rag with mineral spirits. Wipe over the board to remove residual traces of wax.

    • 2

      Dry off the surfboard with a clean rag. Place small strips of masking tape around the dings in the surfboard to indicate where they all are to fix them. Place a miniature circular saw blade into the tip of your drill. Cut out any rotted pieces.

    • 3

      Combine polyester resin in a plastic container with glass spheres to make filler according to the manufacturer's instructions, such as a 50-50 or 40-80 ratio of resin to spheres, depending on how thick you need it and how deep of a hole you are fixing. Mix the contents in the container thoroughly with the stirring stick.

    • 4

      Apply the filler to the ding. Let the filler set. Trim off any excess with a knife. Place 80-grit dry sandpaper onto the power sander. Sand down the filler until it is even with the surface of the surfboard without any lumpy spots.

    • 5

      Mix epoxy resin and hardener together. Apply the mixture to the surface of the filler with a paintbrush. Cut a piece of silicone fiberglass cloth to the size of the ding, overlapping the edges by 0.5 inches. Place it on the ding and coat with more resin/hardener until wet.

    • 6

      Wait 24 hours for the patch to dry. Sand out the high spots with 150 grit sandpaper. Place masking tape at the edges of the patch. Apply more resin/hardener to ensure the patch is completely covered, coating the edges of the tape.

    • 7

      Brush out any air bubbles you find. Pull off the tape just as the resin/hardener begins to gel. Let the resin/hardener dry. Continue sanding with the 150-grit sandpaper until the edge line disappears into the surfboard. Switch to 220-grit sandpaper for finer sanding until the patch is smooth.

    • 8

      Place soapy water into a squirt bottle. Wet sand the patch by hand using 320-grit wet sandpaper and squirting water on the surface. Sand until the patch turns clear. Continue sanding with 400-grit sandpaper until the surface looks nice.

    • 9

      Dry off the surfboard. Apply automotive clear coat if your surfboard has a clear-coat finish or use polishing compound on a surfboard with a gloss coat finish.