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Step 10: Installing the Fin Boxes

Since I am installing Futures Fin boxes, these fin boxes need to installed before the glassing of the surfboard. There is a template kit that is used to installed these types of fin boxes but it's super expensive. I used to just trace out the top and bottom of the fin box, router it by hand by adjusting the depth of the router bit. For this build I made my own wooden templates and used a bushing kit in my router, the process is very similar to making inlays in wood working. That way it was repeatable and consistent.
Since the board was sanded after the initial marking of the fin boxes we need to remark the location of the fin boxes.

Using a wooden template, router with bushing guide and a 1/4" single flute router bit, the first part of the fin box was routered. I find it easier to do multiple passes increasing in depth with each pass. I made a depth guide from wood as well to see what the idea depth for the fin box would be. For the larger flange of the fin box was routered out with a second template.

You want the top of the fin box to just sit slightly above the surface of the surfboard, this is so it can be sanded open after glassing and hotcoating at a later step.

Once I was happy with the placement and depth I mixed up some epoxy and set the fin boxes in with the fins installed, if the fin boxes didn't stay seated I taped them down, let the epoxy set then remove the fins.

The last thing to do is take some masking tape cover over the opens of the fin boxes and screw holes, fiberglass will be applied over the finboxes, they will be sanded back open later.