How to Make Longboard Fins Out of Wood

On surfboards, fins are required to allow the board to travel in a straight line or to make sweeping turns. If your fins have been damaged, they will need to be replaced. Making your own fins from wood is a cost-effective, convenient way to replace broken or damaged longboard fins. With some common tools and a supply of wood, you can start producing your own custom wood surfboard fins in no time.

Things You'll Need

  • Marine grade plywood (5/8-inches thick)
  • Jig saw
  • Sandpaper (200 and 440 grit)
  • Urethane sealant paint
  • Paintbrush
  • Epoxy resin and hardener
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Instructions

    • 1

      Draw the outline of your fin onto the flat surface of a sheet of marine grade plywood. Other non-laminated hardwoods can also be used depending on your preference. Trace an existing fin or design your own unique custom fin shape. Ensure that the spine of the fin that fits into the slot in your board is the same length as the slot and is straight to sit flush in it.

    • 2

      Cut out the fin using a jig saw following the line drawn in Step 1.

    • 3

      Sand the fin. Sand the leading and trailing edges of the fin to a soft point. The fin should resemble an airplane wing when fully sanded when looking at the profile of it. The thickest part of the fin should be about one-quarter of the way from the tip to the tail. Feel free to experiment with different thicknesses and sanding to find the type you like most. Ensure that the spine of the fin is straight and does not have a beveled edge.

    • 4

      Paint the wood fin with a urethane sealant to protect the wood from absorbing water and to protect it from light damage. Allow for a day for the urethane coating to properly cure and harden.

    • 5

      Mix equal parts of epoxy resin and hardener, then apply a small amount along the spine of the wood fin. Insert the fin into the slot in the back bottom of the longboard and allow for 24 hours for it to cure before using the board in the water.