Fin glassing help: necessary to run cloth all the way up my fins? and other questions....

im about to embark on my first glass on fin job… my fiberglass fins came in the mail today, they are this model: (true ames)

someone mentioned that it is not necessary to run the football patches all the way up the fin, because it is already perfectly foiled, and im guessing the only advantage of glassing the entire fin would be that it would add a lot of strength. im also liking the idea of not covering the whole fin in cloth, because im not entirely sure on the whole excess cloth trimming process after the fins are glassed.

i dont understand how you trim the excess cloth down to the point that the fin is as perfectly shaped as it was without the cloth around it. do you just have to carefully sand to the shape of the fin under the cloth? what is the proper method?

also, im dont plan on going any further than my hot coat with this board. when i hot coat (after my fins have been glassed on) do i coat the fins themselves with the hot coat too? or just the base of the fins?

thanks for any help, i just really want to do this first job right, and not have any regrets…

From my experience (and that’s not much), I run the football patches up each side (2-3 on each side), and then cover the whole fin with a large patc of 4oz., completely covering the fin. Then when hotcoating, start with the fins first (Thanks Kokua!), covering the entire fin(s). Then sand carefully and trim/sand the excess around the fin.

sand the fins carefully? i thought it was easier to trim the fin excess cloth while it was initially gelling? and if youre not using the method you just mentioned is it necessary to sand the fins after the hot coat?

I put roving along the base before my fiberglass patches. Mike

Howzit Cross, By all means trim the excess glass before the resin completely hardens but not to soon or the glass will delam. What I do before hot coating the fins is put a sweet coat on the glass which will fill the weave and give you a little leeway when you sand them. You sand the fins when you sand the board.Aloha,Kokua

I’ve stopped doing the full-fin patches. I use successively wider strips, each covering the edges of the smaller patch beneath. Depending on the strength I expect I’ll need, I use roving and either two or three small strips of 4 oz. I trim after firm gell with razor blade. Sand to desired shape when nearly hard with 80 grit and “finish” sand with 120. Then I hotcoat the whole thing and final sand fin and board together.

That’s my method.

FYI : I put a layer of glass under the roving/rope.

Hi Herb,

Do you put a large patch before the roving or a smaller ‘football’ patch before the roving? What I would like to know is your method,of course. Mike

Just a small football patch Mike.

It seems to give it alot more strength for the weight.

I tack the fins then lay up the first small football/roving/large football x 2.Herb

Got it Herb. Thank you. Mike