SUP Foil Wing

[atomic-chomik]

So i picked up some 1 inch Divinycell and was dreaming up an approachable and functional wing to shape. My first thought is similar to a Stringy wing, with a bit lower aspect ratio(deeper profile). Any thoughts on this? Putting in anhedral i believe is beyond my skill-set(unless there are solid suggestions out there).

I have access to kevlar cloth(any one work with it?) and carbon fiber. As well, i have access to vacuum bag setup so all good there.

[BWD]

I am pretty sure d-cell is not hard to thermoform but mainly heard of it done with 1/2 to 3/4" thicknesses.
Probably you would be ok to make an arched mold of thin plywood or something and heat foam in an oven if you have a big oven. Would take a while due to thickness. Then bend it over your mold, secure and let cool. Maybe if oven is small you could use say a 12" or so square of foam, then once molded to anhedral, saw it into two 6x12 pieces with matching curve you could glue together for a 6x24" ish span wing. Could even glue together with a block of g10, hardwood etc in center for extra strength at attachment point.

To laminate, vacuuming bagging with carbon would certainly be good. Wouldn't hurt to have an outer layer or 2 of glass against scratches etc I think. Not a whole lot of carbon needed to take the regular loads but if you hit something or it is thin and gets scratched heavily it could fail.

Best wishes with it!

[atomic-chomik]

BWD thanks man. Have any suggestions as to what heat and for how long the foam should go in the cooker for? I figure it would be after its shaped so there is room. Im thinking a 26 inch wide wing should suffice.

[Mikey]

Is dihedral needed. Zeeko seems to do ok with flat wings (carver & spitfire)?

[davesails7]

I have access to kevlar cloth(any one work with it?) and carbon fiber. As well, i have access to vacuum bag setup so all good there.

Carbon fiber is stiffer than kevlar. Also, when kevlar fibers get wet, they begin to lose some of their strength. Probably not a problem since they would be fully encapsulated in resin. The best foils are carbon for a reason. I have heard of kevlar being used from time to time, but it seems like a mistake. I think carbon is definitely better for hydrofoil construction than kevlar.

Anhedral (or is it dihedral, I'm always confused. wingtips curved down) lets you roll a bit further before the wingtip breaches the surface. When the wingtip does breach the surface tough, the curved wing will have more of a loss of lift than a flat wing. It also gives some stability in yaw and roll.

Most SUP foils have 60-70 cm struts. If you're going to make a 26 inch (66 cm) wide flat wing, it seems like that would limit your carving ability with no downward curve or angle to the wingtips.

Looking at others who I'm sure have tried many iterations of design, Takuma, gofoil, and slingshot sup foils all have curved wings.

[TomW]

What density of Divinycell? forget using kevlar. Use carbon.
I'd shape the wing without anhedral then try to heat the foam and bend it over a simple jig and let it cool.
Or, put some blocks under tips, screw center down with small wood screws, laminate the bottom . Let it cure a few days, then cut off/grind off screwheads. Laminate will be in tension and hold shape. Might spring back a little.
You need to do some experimenting, Divinycell can break when bent.