Has anyone tried laying up a sheet af multible layers of fiberglass coth and epoxy resin thick enough to be used for fins to fit in boxes? If so what were the results good or bad?Or why or why not? Thanks
I make a hi-density foam sandwich with an epoxy and glass body. I used 9 layers of 4 oz. and 7.5oz. for the body of the fins. After foiling they were very noodly, almost to the point of scaring me, but after glassing them on with a layer of 7.5 under 4 0z. and 2- 7.5’s and a 4 on the foam side, the became nice and ridgid. The were so strong that my test pilot buried them in the rail of a drop in at Lowers and didn’t have a scratch on the board or fins.
The nice thing about using Resin Research epoxy is, after doing the lamination of the fins, I was able to sand them down cleanly BEFORE hotcoating them, after the normal sand job I didn’t grind into the weave, clean
My issue with a high density foam sandwich for box fins is keeping the strength in fin tab and how the make that happen without making the process too complex, but I still have a lot to learn. (any tips?) For center fins over 8.0" Jim’s process is an excellent one. For glass-ons it’d work great.
I’ve stacked glass cloth with R.R. epoxy and I comes out about 20% thinner than Poly. I like the result quite well. It’s just a little milky when you get a few layers built up but man does it make a great fin.
Mahalo, Rich
I did a pair of cutaway side fins for a fish using RR epoxy, I laid up a thin carbon panel, cut the outline, spread microbubbles on one side, foiled the fin by hand in about five minutes with rough sandpaper on a block, and glassed with 3 layers of 4 oz each side. They are pretty thick foils, and stiff as can be, though they seem to flex just a little at the tip. I left the microbubbles off the base, and cast them into a pair of lokbox boxes, right in the board, and set the toe and cant just like glass-ins. I popped them out, dremel-cut the slot, and good to go. They almost float in water…
From my backyard…
wells
Jim ,
If my fins are made of epoxy , cut n shape to size like FCS . Do i still have to glass layers of fiberglass coth to make it harder or epoxy are hard enough for itself ?
Thx … beginner .
Yeah, when we say epoxy, we mean an epoxy-glass panel. Areas of pure epoxy won’t have much in the way of strength, it’s gotta be fiber reinforced.
Have a look at the wooden fin thread of a few weeks ago for an excellent run down of how to make wooden fins, with pics and instructions, courtesy of Bert Burger. Also search archives, lotsa stuff…
Wells