Fin core material

I have a question about building wooden cored fins. I used some 1/4" cedar off cuts from another project and cut out fins from it. I hand shaped the foils with a piece of 100 grit paper, while sitting on the beach waiting for the tide, over a two day period.

As soon as I started foiling them, I realized I had cut them out wrong. The grain of the wood runs horizontally across the fin, instead of vertically up the fin. I figured I would use them for practice foiling and continued on.

After finishing with them, I have grown kind of attached. I really want to glass them and put them on my next board.

Is the core where a fin gets it’s stregnth? Or the glass?

Is the wood inside just a good looking, light weight filler material?

They are pretty flexy. Actually really flexy. But they are tabbed for FCS plugs, should I just glass and try them?


Just glass em up, if you can get some uni directional glass use some under the cloth at 90 degrees to the grain of the wood, that should stiffen them enough. If not, put a couple more layers of 4oz on with the weave running perpendicular to the grain.

uni=glass might help but carbon fiber would be a better bet…actually I wouldn’t waste the time on glassing them…the problem is the basis of your fins have a “born to snap core” especially the tabs. Just re-make them and remember the grain factor…your time will be better spent…as well as waste and $$$.Herb