Making Wood Surfboard Fins

Making your own surfboard fins is a way to customize your surfboard just the way you want, while also saving you a bundle of cash. Fins are an integral part of any surfboard and there are about as many different designs out there as you could imagine. Instead of paying for commercially produced fins, make your own using some commonly found building materials. These fins will perform just as well as any other, allowing you the freedom to alter and adjust them until you find the design that works best for you.

Things You'll Need

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

    • 1

      Draw the fin outline onto a sheet of marine grade plywood. Alternatively, if you already have a fin you are happy with, trace its outline onto the sheet of plywood.

    • 2

      Cut out the drawn-on outline using a jig saw. Have a friend apply his weight over the sheet placed on a a work surface to keep the sheet from moving while cutting.

    • 3

      Sand the edges of the fin sharp. Angle the edges of the fin to a knife-like edge to help reduce its resistance when gliding through the water. When looking at the fins profile, or from the bottom, it should resemble a teardrop shape, with the thickest part being closest to the leading edge, and the trailing edge being the most sanded, somewhat shaped like an airplane wing. Leave the upper edge of the fin that will be secured into the slot on the underside of the board square to allow it to fit snugly.

    • 4

      Paint on a layer of urethane sealant once the desired shape has been attained through sanding. Use a paintbrush to apply a coat of sealant onto all surfaces of the fin. Wait two hours for the first coat to dry and cure; then apply a second. Urethane will form a watertight membrane over the surfaces of the wood, preventing moisture from penetrating the wood and preserving it for as long as possible.

    • 5

      Prepare your epoxy mixture by mixing the resin and hardener according to the manufacturer's directions. Use a toothpick to apply the epoxy mixture to the square spine edge of the fin as well as some into the slot at the back underside of the board. Insert the fin into the slot and then set the board aside for 24 hours to allow the epoxy to properly cure and harden.