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X-man
X-man
WA
325 posts
WA, 325 posts
3 Nov 2004 9:58am

I actually plan to make a new board in the same way than the previous one; by laminating plywood, but I want to make it lighter.
What I did the first time was taking out as much wood as I could, leaving outline, stringers and also the feet positions, replacing the rest by polyurethane foam, and finally coating it with fibreglass/epoxy.
What I thought was to take out more wood this time, use polystyrene instead of polyurethane, and use carbon fiber for the bottom of the board and to reinforce the stringers. It's a bit difficult to explain all this without a diagram, but hopefully you can visuallise.
The thing is that I'm not sure if it is going to make a big difference. Does anyone have some info about where/how to use carbon efficiently?
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decrepit
decrepit
WA
12885 posts
WA, 12885 posts
5 Nov 2004 9:29pm
Why not take out all the ply wood, and use the standard construction method??? Or are you achieving a lighter than standard board???

Carbon is a bit tricky, it's very stiff, so you don't need much to get required stiffness, but it isn't very impact friendly, so it's not an ideal external skin. Mixing it with other materials in tension is also risky, as the carbon will probably take all the load, because it will most likely be the stiffest.

If you can post more details of what you intend, that would help.

decrepit
KAOS69
KAOS69
WA
1012 posts
WA, 1012 posts
6 Nov 2004 1:10pm
whats the idea behind the ply wood . boats are made of it . if you are going to use wood you would use veeneer which is only .6 mm and when soaked with epoxy will make for a impact strengh mixed with carbon matt maybe two layer around heels and gybe area solid as you will ever need . carbon doesnt make it lighter just stiffer . If you are making a full samwich board you dont need stringers . you should be able to make a 90l board with pads , straps and boxs under 6.5kg if not go back to the drawing board and learn to use the vacum bag method better as lots of weight can be take off
bluejuice
bluejuice
WA
334 posts
WA, 334 posts
6 Nov 2004 10:23pm
xman are you making a kiteboard or sailboard ?

a.k.a. KA202
X-man
X-man
WA
325 posts
WA, 325 posts
10 Nov 2004 11:56am

I am making a kiteboard actually, 130cm long, so It wouldn't be very heavy anyway. I wouldn't even try to make a sail board out of plywood! it's far too big! I made the kiteboard I have now in the same way and it is not heavy, but not as light as it could be.


X
leski
leski
NSW
661 posts
NSW, 661 posts
10 Nov 2004 6:40pm
why not doing one with a Airex/Herex/Divinicell core.
You could get sheet of Divinicell that are probably 2cm thick which should be ok , if not you could always
lamintate a couple of 5mm sheet together. (and Divinicell is easy to shape.)
So basically the same that you did with the plywood but using divinicell instead.
It will be for sure really light. I wouldn't worry about stringers, but if you want to be sure it is dead strong then you could always add some.
good luck
justinb
justinb
WA
7 posts
WA, 7 posts
4 Jan 2005 12:11pm
why are you all using **** foam? why dont you try corecell way better foam.
bluejuice
bluejuice
WA
334 posts
WA, 334 posts
4 Jan 2005 1:22pm
I'd like to use corecell but last time I enquired it was tice the price of divinycell and the closest supplier was in New Zealand, Which made it very uneconomical to ship. Do you know of any suppliers in W.A. ?

a.k.a. KA202
decrepit
decrepit
WA
12885 posts
WA, 12885 posts
4 Jan 2005 6:04pm
quote:
Originally posted by bluejuice

I'd like to use corecell but last time I enquired it was tice the price of divinycell and the closest supplier was in New Zealand, Which made it very uneconomical to ship. Do you know of any suppliers in W.A.



A few years ago "Fiber Glass & Resin Sales" had a display of it in their counter, but when I enquired about it, they weren't that keen to sell it!! Told me it was too expensive!!!
Is it that much better than Herex or Airex???

decrepit
hosko
hosko
WA
393 posts
WA, 393 posts
6 Jan 2005 2:17pm
has anyone tried making one with a nomex core and carbon over that?
i'm a sailor as well and all the latest skiffs are made like that i think, well i believe my cherub is. but we use kevlar on the inside of the hull as it is stronger but too hard to sand/grind (and thus get a decent finish) which is why we dont use it on the outside.
I also think kevlar is considerably heavier than carbon. so maybe not good on kiteboard.
sorry just me thiking out loud....
crashtestdummy
crashtestdummy
VIC
63 posts
VIC, 63 posts
13 Jan 2005 12:06am
Whats Herex or Airex? how does it compare with Divinicell? What about corecell whats the diff with that? Anybody in Melbourne suggest any suppliers?. Are any of these the same as 'blue foam'?
crashtestdummy
crashtestdummy
VIC
63 posts
VIC, 63 posts
13 Jan 2005 12:08am
.... and Nomex?
decrepit
decrepit
WA
12885 posts
WA, 12885 posts
13 Jan 2005 8:55pm
quote:
Originally posted by crashtestdummy

Whats Herex or Airex? how does it compare with Divinicell? What about corecell whats the diff with that? Anybody in Melbourne suggest any suppliers?. Are any of these the same as 'blue foam'?


This is off the top of my head, so may not be absolutely accurate.
There's 2 types of vinyl foam, cross linked & linear linked. one of them is hard but brittle the other is softer and tougher. Herex & divinycel, are the hard brittle ones. Airex is the tough one, as I think is corecell. Don't know about nomex.
The distributor for Herex & Airex is in NZ, and I think core cell is in Queensland. A Google search should give you all the details.

Blue foam is altogether different, it's extruded polystyrene, basically designed for insulation purposes in damp/wet conditions where the uptake of water would reduce insulation properties.
If you do a google search add "dow chemicals"



decrepit
gremlin
gremlin
WA
55 posts
WA, 55 posts
13 Jan 2005 9:01pm
Hey blue juice
ATL composites in queensland is the supplier for corecell in australia,and it can obtained in WA through Fibreglass and Resin sales in welshpool.The freight is nothing if you order it with F & Resin sales monthly order!
and your right about the price but it is pretty strong stuff!and easy to shape.i think the last time i brought some a 2400x1220x9mm sheet cost me $190 compared to divinycell at $130
I think corecell is worth the extra $$$
cheers
bluejuice
bluejuice
WA
334 posts
WA, 334 posts
14 Jan 2005 11:17pm
Thanks Gremi got your email

a.k.a. KA202
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