Rogflys

The Grain kit comes with a Fins Unlimited finbox, and very little instructions for it's installation. Pretty much all they say is, "cut a hole for the finbox, use a router or mallet and chisel. Trial fit it a few times and epoxy it in." What they fail to mention is the fin box has a part that has to be ground off after it is installed. Basically the 1 1/4" finbox goes in a 1" deep slot. There are some tabs that are there to sit on the surface of the board to align it correctly. There is also 1/4 inch of plastic that will sit proud of the board that keeps the epoxy from spilling into the fin slot. After the epoxy has set this is ground flush with the top of the board. Hopefully leaving a nice smooth surface. More on that when I get to it............

Here is how I went about cutting out the slot, and installing the finbox:

First I laid out where the box was to go (this had been thought out before the top planks went on since there had to be blocking on the inside of the board) and scored the fiberglass with a razor knife. I am about 5 3/4" from the tail of the board to the finbox, along the centerline.

I then peeled the fiberglass out and and put tape around to protect the surface. I used my Dremel with a router base to freehand the slot. The bit for the Dremel is only long enough to get about 5/8" deep, so I then set up my router with a pattern bit, using the top portion of the slot as the pattern for the bearing to ride on. A couple of passes later the slot was complete.

The router also left a nice clean slot. I think to do this again it would be worth making a template to cut the whole slot with the router.

You can see the small tab on the end of the box, and the 1/4" that sticks above the surface that will be ground off later.

I put more masking tape down to catch any drips and squeeze out of epoxy. The towel is to protect the other side of the board from the strapping planks I used to clamp with. The clamps are just pulled snug as not to distort the plastic fin box. The tape on the straps was to hold them together during the one man clamping show.

Posted by Roger at 9:48 PM