DIY Home Made wooden Hydrofoil fins

[windfreak74]

hello Bill,
thanks for the tip!!
its a easy fix !
thin bit, drill thru put another nut on top.
I get to work on it!
i wanted to be beautiful all Wood no bolts in sight!

[windfreak74]

Hello guys,
Got to finish half of the mast profile this weekend!
Couldnt finish the sanding but this is what i got
its 860mm long x 130 mm wide x 8mm thick.
My guess is mast foil will be somewere in the 19mm thick x 135mm chord.
there will be a 4 layer of 6 oz. fiber glass in the middle to bond both half to avoid shearing in the midlle due to flex. and avoid flex by puting fibers in 45° degree layup.
Please comment construction!
16 hours logged in!
Pedro

[BWD]

Put the fiberglass on the outside wrapped around the mast. In the middle it doesn't do any good.

[windfreak74]

Thanks BWD!!
hows the cloud working for you?
I got one too! great lightwnd videos by the way!

Pedro

[windfreak74]

Hello BWD,
since you pitched in, here is a glassing question.
how many layers of 6 oz glass should i rap around?
zneffel? any comments?
how about carbón in 45°degrees to make it laterrally stiff?
to many questions not enough carbón!!!
what to do????
Pedro

[windfreak74]

hello zfennel,
composite newbie speaking!!!
can you comment layup?
sorry for my misspeling of your name:oops: !

[BWD]

OK, but I can only give a guess and I am not an engineer, so take this with a grain of salt.
I would go for at least 4 layers of 6oz in epoxy, 6 layers would be better but heavier.
With only 6oz fiberglass to work with, on top of a strong wood core, I would put all cloth on the bias, +/-45 degrees, because the torque is a bigger issue than lateral flex.
One more thing you could do to help the stiffness is to thicken the mast.
If it's made of left and right halves, a 3-4mm layer of wood veneer or marine plywood between them would add enough thickness to make it much stiffer, at a total thickness of about 26-28mm (19mm wood + 3-4mm ply + 2 x 2mm glass +1mm glue between layers).
It might not be as pretty though. This might be worth doing if you don't have carbon.
If you do have carbon, +/-45 degrees is the way to lay it.
2 6oz layers might be enough, 4 would be a lot, so maybe 3?
I think if you had a light (weak) wood or foam core, you would also want a similar amount of carbon to run at 0 degrees (vertical unidirectional).
Finally, if your wood is really strong, you probably would be ok with less glass.
That's the best I can do for now....
Good luck!

[Hawaiis]

Windfreak:
What kind of wood are you using?
Are you gluing 4 pieces together for the strut?
Mahalo

[windfreak74]

Thanks BWD !
very helpful.

Hello Hawaiis,
im using bamboo flooring. I glued 2 pieces by the tongue and groove connection.
that gives me a 192mm area x 15mm thick to route.
But i think that i will do it again with and glue 2 Wood florings together tyo get 30mm thick.
That way i can route a single piece of about 20mm before glassing.

hope this gets it clear!!
Pedro

[windfreak74]

Hawayys,
Its 4 pieces together like you mentioned.
I will do this this weekend to advance a litlle more.
Ill leave th first piece as practice.
Mahalo!