first attempt

[phatfil]

after reading a bit about building boards i decided to give it a go. I haven't actually kitesurfed on a board yet, so don't know much about the boards. Read a whole lot here and places, and today went to buy some marine ply.

I'd been told it's possible to use a thick piece (larger than 12mm) and use steam to bend it. The guy at the place I was buying the ply at convinced me this wasn't the way to go, and to use 2 or 3 pieces glued together. So I got 3 pieces of 6mm ply, because looking at it, 12mm (2x6mm) seemed pretty thin to me. When I got home, 3 pieces seemed pretty thick though. So I'm trying with 2 (12mm). I drew the design i thought should be ok on a graphics program and printed it, drew it onto the wood, and cut it out.



I decided on 140x40cm. Applied the glue (currently waiting 12 hours to dry) and left it like this:

(yes, that bin is full of water )
It seemed like it might be too flexible. I'm hoping the glue will lessen the flexibility - does this happen?

I was inspired to make the fins out of the ply too (from a picture somewhere on this forum), so I'll do that.

Not really sure what i'm going to do for footstraps yet... will post more as it gets made.

[mx5alan]

Anything above 12mm is too thick and makes the board very heavy.
My board has no rocker or fins.
For foot straps on my board I am using some Scrub Mountainboard bindings which I have offset at 15° from center line of the board. Distance between them is about shoulder width.

C/L --------- / -------- -----------

/ at 15° through center line

[phatfil]

thanks for that, i'll look into it
today i used a rasp (think that's what it's called) for lack of better equipment to rasp away the top edge, and also cut out some fins. my brother had a cool idea of printing out a photo of some fins from some site and using that as the outline, worked well. I'll use a chisel to cut slits on the bottom, (not all the way through) slide the fins in and glue them into place.

[buttercutter]

That board looks really nice. It is probably a bit thick though. Does it seem really heavy? I would recommend buying some real straps, footpads, and perhaps even fins. You already saved about $600 on the board, so might as well splurge on the accessories.

[psa]

with two plys only it should not keep the curve well. You should use 3 plys when using glue-method. I have used 1 x 9 mm ply and wetted it for 24 hrs and after that put it to the rocker table and the whole thing in to the 70-100 C heat for 3-5 hrs. And let it cure in "after heat" for 24 hrs. Curve stays well. And I have used thin 90 gr/m2 glassing for top and bottom. Also varnishing only is OK.

I also recommend you to use real kite-pads, straps & fins. At least straps, because with straps you attach yourself into the board.

12 mm is the max. thickness. We here have used 500..700 kg/m3 ply ( birch-700 & fir-500). Marine ply is too heavy at least for us.

[phatfil]

yeah i am a little worried about the weight. right now my dodgy home scales put it around 3-4kg. (this thing better float!)
I've made some fins which i like, so i'll use them, but i'll buy footstraps/pads (i found they're not all that expensive anyway)

the guys at a marine shop told me epiglass "everdure primer and sealer" (2 part epoxy timber sealer) is what i need for sealing it, then some sort of varnish. im worried this is just going to make it heavier.. don't know if anything else can be used though

[Guest]

I just brushed clear polyurethane on it and it sealed nicely. Don't go overboard with the expoxy because it will make it heavier, and also you may find that you want to modify, chop, sand etc after riding it. I belt sanded a concave through a few layers and it made it lighter and the concave bottom makes it ride better too.

[phatfil]

strange.. this thread disappeared from the forum.. see if this gets it back

[psa]

Varnish over epoxy is too much. one...two layers of varnishing is enough. Or one layer of epoxy only. If you can make the first layer of varnish thinner it should make weight little lighter. The reason why I used 80gr/m2 glassing was that it weights almost same as varnishing. And Glassing makes the board last loanger (scratch resistant) and makes the board less flexible.

After we have been doing some ply boards my conclusion is that when the ply is 12mm thick (1/2") glassing is not needed when I use birch ply. And if I use fir (lighter than birch.. 400..500 kg/m3, but strong/weight-ratio same as birch ply) and the thicknes is 9 mm (4/11") then I use Glassing.

My light wind ply 150x45x0.9 + glassing + starps+fins weight totally 3.9kg /8.6 lbs.

Anyhow there are numerous ways to do plys - find your way. My goal is to keep it simple, because every year new things are coming and my progression in riding skil is still quite big because I started early last year.

[zfennell]

i not sure if anyone mentioned this..
but your supposed to bend/clamp the assembled plys to shape BEFORE the glue sets.

otherwise, you have the same piece of plywood that the guy from the lumberyard talked you out of.

but the truth is, everything works and flatter is better than too much rocker.

-bill