Hi there, the idea came out of the fact that I bought some old kite waveboard for cheap, but the trackerfins that were in there were too small and flexible, in the jibe you had no feeling and nice sprayed turns were not into it, so propably the board was drifting too much due to the too small and flexible fins.
Now I had a plate of aluminium and a 3 layers plywoodplate.
The idea that the trackerfins are without a profile on the inside, gave me the idea to put the aluminium plate on the inside and this would be great because you could screw the allen screws against it ( wood would not hold it)
Secondly the outside of the fins, would be wood, easy to profile and lightweight too.
I copied another trackerfin on the wood and the aluminium as well, cut them out, and glued them together with Tec7 a silicon based glue that glues everything together.
A night inbetween a benchpress and the next day we could start grinding and shaping , which turned out to be not that difficult.
6layer plywood would have been better to controle the profile and it would look nicer but these are just proto's, to see if they hold the pressure ( maybe 6layer plywood would be stronger, we will see)
If this holds, I will be going a good time this winter in makeing all kinds of fins, they turned out really light :now 70grams for one, and still need to work the epoxy that I pored over the wood.
Any ideas/remarks would be helpfull, have not been able to test them yet.