I’ve been wanting to try a surf foil sized wing but couldn’t justify the cost of a new foil so I tried my hand at building one for my much loved Stringy foil. I glued 2 layers of already warped 1/2in plywood together and shaped with hand tools. I just shaped a airfoil that felt right, semi-symmetrical, no guide. The lines of ply layers helped make it uniform.
The result exceeded my expectations! Slow, stable, but plenty maneuverable for carving swell. It is draggy and vibrates at speed, but foils at a walking pace with little kite power.
I got lucky and haven’t needed to shim or adjust the foil in any way other than just bolting the big wood wing in place. Made from scrap plywood with 1 layer of cheap 6 oz fiberglass and epoxy, the stainless bolts cost as much as the materials. Foil is 31 inches wide, 9 inches middle chord and 1 inch thick in middle, tapered to the tips.
First session took a few min to get used to it but soon was doing flying jibes and foot switch a bit more easily than my regular Stringy front wing. I miss the speed and apparent wind of the smaller wing, but riding swell with this is a fun new experience. You can go sooo slow and really feel the energy from the water.