Foam core fin question

I have some EPS offcuts that I am thinking of hotwiring/shaping into some fins. How would you guys approach adapting a flat-bottomed (like a glass-on fin) shaped EPS fin to fit a finbox (Bahne type)? Would you do it before or after glassing the EPS core?

I was thinking of either shaping the eps, sealing it, making the finbox attachment out of whatever was on hand, and making a mold of the whole thing, but I would prefer using the EPS core as the fin itself (instead of casting heavier fins), just wondering how to make the interface with a finbox strong enough…

Ideas?

Thanks,

JSS

Hey Max,

I’d be very suspect of using eps core for fins.

But if you did, you gotta lay down heaps of glass and reinforce the bottom where the fin attaches to the board.

Risky business…

Plywood is cheap and easy to foil with a power tool.

Balsa shapes easy too, and its cheap…

poplar too.

Thanks craftee, that’s what I was thinking as well, just wanted to bounce the idea off of a few people. Since I can hotwire very accurate foils (I personally can’t get the same shape repeatability foiling wood with tools), Maybe a mold would be the best way to go…casting them with a balsa or foam core?

JSS