Here is a time saving easy-to-make jig for center fin boxes.
It’s best to sand the deck enough to get the wax off where the clamps will be so they don’t slip. Light clamp only.
To cut the center slot: Draw out the size you want. I use 1/8" over the box size.
Tack four pieces of wood on the lines you just drew. 1/4" by
1" is fine. Then drill out the center of the slot will a regular
drill, but stay off your line. Then use the router with the
pattern bit to cut the template. The bearing will run
on the 1/4" x 1" wood. Remove the tacked-on
pieces of wood, and you have your template.
I glued the wedge-shaped pieces on the bottom so the template wouldn’t rock, and to get easier clamping. Doug
