If you install the finbox before or after laminating.

I have always installed prior to laminating and for some reason can never really get a great looking instalation. So i was thinking that routing after laminating might make ffor a cleaner final product.

thanks in advance for your thoughts and feedback



 We always install our fin boxes after the hotcoat.  We sand smooth, then router, and install. After this cures we grind the box smooth and gloss.  This makes a nice neat clean installation.


But what if you wanted to put a fin patch on?

You can layer a fin patch or glass a fin over a sanded hotcoat, it’s fine. The sanding can be deeper into the lam coat if you really care.

For fin boxes, we’d always tape over the box area, making the router bit last longer, not needing to go thru another coat of resin.

You should ALWAYs cap your boxes, and layer a couple of “foot” lams for glass on fins.

Do you just put a piece of tape on the foam? …keeping you from having to route through resinated foam/stringer…

that’s a great idea.

If you want to cap a box, just put the glass over the box and gently saturate the cloth with resin using a small brush. If you don’t over saturate, the resin will fill the cloth without going into the box. You can then trim the glass over the box either with a razor blade when gelled or with a trim router when finished. O’Fish’L’ does have a box that is capped which goes into the blank for a standard FU fin. I’ve had nothing but good results using that box.