Used 40 layers of 6oz glass with cotton cloth in the middle, the same cloth I used for the nose of my board http://www.swaylocks.com/forum/gforum.cgi?post=256445;search_string=first%20board%20pics;#256445
I also experimented with boat resin (cut out on the right) and I think about 20 layers of cloth, about as many as I could make myself cut before I got tired of it. The boat resin turned out pretty ugly since it’s so yellow. No sparklies though I think. Maybe because of the resin, maybe because I wasn’t as tired when I did it because 20 layers is easier than 40.
This is a for a fins unlimited box. I know somewhere I had read exactly how many layers to use with what boxes but I was too lazy to look it up again. Turns out 20 layers is too few for the width and 40 layers is too many. I think I used 64oz of resin for the 40 layer fin. Not going too much bigger than the fin on the rectangle I laid up. I also wasted proabably 32oz of resin burning it by having it sit in the cup. After that I started using dixie cups to wet out 2-4 layers of cloth at a time.
Left something to clamp at the bottom while I foil as well.
Cut it with a band saw, tended to wander, probably needed a thinner blade. Cleaned up the shape with a dremmel when I went to foil.
Clamped into a vice and foiled using first the dremel to rough the edges then a palm sander to sand… and sand… and sand… till I got sick of it and said good enough. There is a rather wide flat area in the middle of my fin.
Dremmeled the slot tab, one side is nice and smooth, the other side has waves in it. I dremmel better on the right