How to Fix a Fin on a Surfboard

An epic wave set is on its way so you grab your board only to find the fin is broken.The fin might be partially coming off or it snapped off altogether.Taking your board to a repair shop is one option. Learning to fix the fin on your surfboard yourself is another option. Self repair can save you money but it can also end up costing you more money down the line if you do not take precautions.

Things You'll Need

  • Epoxy resin (for epoxy surfboards) or polyester and sanding resin (for fiberglass surfboards)
  • Large-gauge needle, syringe
  • Two 1/2-inch-thick to 3/4-inch-thick pieces wood, 4 inches long
  • Two C clamps
  • Fiberglass cloth
  • Masking tape
  • Fin rope
  • Hardener
  • Sander
  • Sandpaper
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Instructions

    • 1

      Determine what type of foam is in your surfboard. Using the wrong kind of chemicals can destroy your board. If you have any doubts about the type of foam, do not attempt the repairs on your own; take your board to a surfboard repair shop.

    • 2

      Sand the resin holding the fin to get the fin to release. Remove the fin from the board.

    • 3

      Repair the delaminated sections on the fin by working the resin under the surface with a syringe and a large-gauge needle. Clamp a board piece on either side of the fin, pressing it together. Allow the resin to cure and then sand the fin. For larger repairs, consider replacing the fin instead, as repaired fins are weaker and therefore prone to further damage.

    • 4

      Dry out the surfboard. Reattaching the fin without drying out the surfboard will seal water in the board, causing damage.

    • 5

      Fill any hole under the fin the same way as a puncture ding, and after curing, sand the filler.

    • 6

      Sand the area around the surfboard fin to about 3 inches on each side.

    • 7

      Tape off the area around the 3-inch overlap to collect any resin that might leak onto the rest of the board.

    • 8

      Apply a nonhardening resin to tack the bottom of the fin to the board, and place the fin on the resin. Make sure the fin is straight.

    • 9

      Cut a piece of fin rope for each side of the fin while the resin is curing. Cut the pieces about 1 inch beyond the front and back of the fin. Cut two pieces of cloth a half inch larger than the fin and with a 3-inch overlap on the base of the board.

    • 10

      Mix the resin according to the directions, saturate the rope pieces and place them on either side of the fin.

    • 11

      Saturate the cloth with the resin and place it over the fin and ropes. Use your thumbs to work out any air bubbles under the cloth and to smooth the slope of the rope.

    • 12

      Cut the excess cloth and rope with a razor blade when the resin has started to harden. Remove the tape, paint a sanding coat over the entire area and sand it.