How to Install a Fin Box

Shortly after I got Kruisechev, I had finished a ride, and was getting ready to paddle back out when a rogue wave came through and knocked everyone off their boards.  While I was inside the washing machine my board hit the ocean floor and my fin snapped off.  I was never able to find it.  It completely ripped out my fin box and tore up some of the glass on the bottom of my board.  My board doctor Peter offered to replace my fin box.
Here are the steps to the process.

First he injected resin into the foam surrounding the damaged area and clamped it down, sort of glued everything back into one solid piece.  Then he made a router jig and cut the hole to the size of the new fin box.  I got a fin box that was the same as the old one, so the router basically just cleaned all the edges up for the new box.  Next cut a piece of cloth large enough to cover the fin box and go 1 1/2 inches extra all the way around.  Paint resin (cold batch so you have some working time) in the hole, put the fiber in, more resin and then install the fin box.  Make sure the fin box is nice and square to the board so the fin will sit straight.  To hold the fin box square while it was setting up, Peter constructed this elaborate rig out of paint stir sticks and hot glued it right on to my board.  He has a trick where once he’s done with the rig, he sprays the hot glue area with rubbing alcohol and it pops right off.

Once it sets up, sand everything down smooth, and apply a top coat of resin.  Be very careful to never get any resin drops inside the fin box.

Not long after the fin box got reset, this board got mixed up in the rocks at Sunset Blvd and one corner of the tail was severely messed up.  Peter saved as much of the original foam as possible and then reconstructed the tail with resin and Q-cell filler (it makes the resin expand but keeps it light) he then reshaped the tail and glassed it.  Good as new.

Leave a Comment