making a 'flex' fin

i might end up shaping a board, and i think im gonna try my hand at making a fiberglass fin. since it’s gonna be on a shortboard shape, i think it’d be best to make a flex fin or something like it…

so what would you reccomend? i know the normal amount of sheets is like 36 or so, so would it be best to make, say 20 of them full size, then gradually make them smaller for the rest of the layers, or what?

i was thinking if i did it like that, i could make two halves, then sandwich a few layers in the middle of the two to bond them, and then do a layer over the entire thing to seal it up. would that work?


you could do something like that - you could use different colors/materials in the different layers to decorate the fin. But the easiest way is just to lay up 30+ layers of 6 ounce at once, then cut out your template (it will be one thickness throughout). Then foil it to your liking with the grinder. Thin and/or narrow sections flex better than wide/thick so foil the fin according to how you want your flex. use a fin you like for reference. and ckeck out all the fin co. websites for inspiration (but not imitation).

use a minimum of 40 layers 6 ounce.rusty uses 56(maybe 52) layers of 4 ounce which is really a better flex than the 6 ounce version.check archives under fins or velo-there are some shots of a flex fin in various stages of being built by Paul Gross.