Carbon Board

[Kite-grom]

I am interested in building a superlight carbon board with a foam core. I would like it to be about 110 cm long and 3-4 cm thick if possible. I am wondering about what type of carbon to get and what kind of foam. Thanks

[sq225917]

mate, if you want a board 3-4cm thick you wont be needing any glass on it never mind carbon....

think in the region of 10-20mm tips to centre thickness if you want carbon.

herex, airex, or any good foam will do.
carbon, look for a decent biax cloth about 140 gms/m2.

you should be able to build a 2 layer carbon board for about 1200-1400 gms for the bare deck.

pre-preg is lighter for boards than wet layup and better suited to carbon construction, wet layup carbon is pretty much just a waste of good carbon.

[Guest]

Thanks. I am going to get started right away, you really think that 140 gms/m2 carbon is enough? It's worth a try. Thanks again

[Guest]

Well this all depends... are you going to be vacuum bagging?

If you're going to vacuum bag there are a few foams you should use and you can sandwhich them together.

You're going to need some H80 Divinycell, EPS foam, epoxy resin, carbon fiber, and possibly some Sglass.

Don't forget to have a rocker table made up with your vacuum bagging setup too, this won't work without that, so just disregard my post if you're not using vacuum bagging.

What you're going to do first is cut out your divinycell rails. Cut out however long the board is plus an extra inch or two, make sure it's about 1" wide, now leave these on the side for a second. Now take your EPS foam and cut out your general shape minus an inch which are your rails. Then you take the H80 foam and cut out the general shape you want(bottom). Now you're going to put a strip of glass (optional) and put epoxy on it all along the side of the EPS foam and then you're going to put your rails onto it and push it tightly together. Then you do the same to the bottom of the eps foam with or without the glass and put the H80 divinycell bottom on it.Now put that on your rocker table and put the bag over it, tape the bag down onto the table but make sute it's air tight. Turn on your vacuum pump or vacuum and let it get to about 20-30 -kpa. Keep it at least vacuumed for 3-4 hours.

Now's the time to really shape it and sand it. Get your sandpaper and sanding block, jigsaw and everything else you'll need. Now you put your real shape into it. Before you just had the general dimensions of your board now is when you really shape it.

Okay, once your done with the shaping process (try to make sure the board stays about 3/4"-1" thick through this whole process by the way, you don't want a REALLY thick board.) Get your board and trace it onto some paper or just directly trace it onto divinycell and then you'll cut that same shape right out of the divinycell.(1/8" divinycell) Put your carbon fiber or glass onto the top of the blank you already have (not the divinycell you just cut) and then wet it down with your epoxy. You will then put the divinycell you just cut out directly on top of it. Put this back into your bag and get it to the same pressure. Wait a few hours.

After 3-4 hours again you will pull this out and you can sand and shape more if it's not the way you want it. But this blank is about 5-10 times stronger and 30-50% lighter then clark foam blanks and just one simple piece of foam. The blank I just got you to make will cost a little more, possibly a little less after all those shipping charges but it'll definently be worth it (this is how I make most of my boards now, not all but most, sometimes I use different materials like balsa and instead of EPS I've tried pour foams)

After you put in your inserts you can just add some eglass or you can do your carbon fiber. If you want a sloppy job just throw the epoxy on there and use a squeegie, but you can also just vacuum bag this and it'll work out nice. Oh almost forgot to mention, you'll only need one layer of carbon on each side and it can be very light carbon... I wouldn't do more then 2 layers on this board and that would still be too much.

Usually after I finish a board I'll buff it and polish and wax it to give it a really smooth really glossy finish.

Are you going to be riding this board or selling it?

Almost forgot, if you want a cheap easy rocker table, get some plywood 4'x8' and only like 1/8"-1/4" thick. Cut it in half so it's 2'x8' then you can cut that down to 2'x4.5' or 5' You will then use the other half of that and put a 1"x1" piece of wood directly in the middle across the two foot section. So you'll basicly have something like this __________________
_________II________
The I's being the 1"x1"

Whenever you want your rocker increased, just put some 2"x4" between the two layers at the very ends.

Simple, easy, adjustable rocker table.

But you should formica the top of it (almost forgot to mention that too)

I'll get you guys some pictures of this process soon... I have to get my camera back first.

[kiteboardingcentral.com]

Damn it, forgot to log in... ^^^

I messed up that diagram too.

_______________
______II_______

Like that... with the 2"x4"s on the end.


I think I forgot to mention that you can just use some eglass or Sglass with epoxy and it'll be perfectly fine... a lot cheaper too.

Hell, instead of the top layer being divinycell, try something new, like balsa... use whatever foams you want really, but they need to be of a stronger sort where the Divinycell is, and where the EPS foam is, it can basicly be whatever since EPS is really flimsy and hard to shape before the Vacuum bagging process.

[sq225917]

eps in a board......havent seen that before...

[not annonymous]

surf and pole boards frequently use eps foam in a sandwich construction.

To me, It doesn't make much sense to use it in a kiteboard:

Surfboards are over 2" thick, but kiteboards are usually so thin and the volume of foam is so low that relpacing some of the 6 pound foam with 1 pound foam will make almost no difference in weight once you add in the extra bit of resin and/or reinforcement required.

Trent

[kiteboardingcentral.com]

It's not just the weight but it'll make the board a TON stronger, hence the reason for less layers of glass.

And yes I did start using this on surfboards and then now I'm incorporating them into kiteboards.

And no it's not my original idea, so I'm not going to claim this as my idea, but I do know it works and it works VERY well.

[zfennell]

@ kiteboardcentral

ok, i'll bite.

what's the average thickness of one of your Dcell / EPS blanks?
and
what would be a reasonable weight for a bare board?


also, you said glass was optional on the inner face of the divinycell.
was that for only the bottom skin ?


your comparisons against surf boards made of clark foam make alot of sense.
but for kiteboards, the standard is 3/4 " thick blanks made from H80.

I'm sure you can make the math work, but i'd like your thoughts on what the real advantages and trade-offs are ?

thanks,
-bill

[kiteboardingcentral.com]

They're 3/4" just like your H80.

I use 1/8" H80 for the top and bottom and 1/2" eps foam.

You don't have to use glass, that'd just add strength and a little bit of weight, if you'd like you can just use the epoxy with no glass then throw it through the vacuum bag. But I'd highly recommend using glass between the top layer of Divinycell and the EPS foam.

I don't have a great scale but holding a 126cm of my board next to a 123cm misfit you could tell the difference.

Once I get my camera back I'll take some pics for you through the whole process and make a new topic.

This is how I make the boards from my site... which I haven't started selling yet since I need to get a new FTP client and I need a DBA and business/tax id's etc.

EDIT: Forgot to add, the biggest advantage is strength and the weight difference. The only disadvantage is it's a longer process and you need more equipment to do this compared to other ways...

I'll tell you what... once I get my DBA and tax forms I'll loan one of you a board to make a review on... gimme an email at Kevinwhite@kiteboardingcentral.com or sales@kiteboardingcentral.com

If you like the board after riding and reviewing it, you can buy it for cheap... otherwise send it back, etc etc.