Page 1 of 1

second WRC Queen

Posted: Wed Oct 07, 2009 4:24 pm
by vol
Oki doky,
second my board quite better, another glass and resin harder
only I have problem with bubbles, I guess my mistake was not enough resin and my laminating technique, next time I'll try with brush roller. Someone tried put to resin bubbles degasser? It's work?
board weight 2.6kg

Re: second WRC Queen

Posted: Wed Oct 07, 2009 4:54 pm
by BWD
Looking good!
Looks like you have enough resin, but maybe some bubbles.
Degassing helps, even if you just use a shop vac, it will help pull bubbles out.
For cosmetic purposes you can do it with a shop vac as well as a real vacuum, but the real vacuum is better of course. Easier and cheaper is to just be careful to not make bubbles while mixing resin!

But it doesn't look to me like that is your problem.
I think the bubbles are under the glass, not within it from a bad wet-out.
Probably the bubbles came from inside the wood core.
If you start with a cool wood core 20c or so, then put resin and glass on it, the resin cure makes heat, which makes air in the wood expand and come out as bubbles. Same if you start the build in a cold room in morning, 15C, and the room heats up to 20C plus as the day goes on.
And if you put it in a press, and heat it up more before the resin has kicked, it does the same thing.
So my advice would be to warm the wood core up with a heat gun to maybe 40-50C, then coat it with resin as it is cooling, and put the glass on. That way any air in the board is contracting and no bubbles should come out. Also you might want to "post-cure" the board instead of trying a high temperature cure. Once the resin has kicked, you can heat things up without worrying about bubbles so much.
Another thing you can do is to laminate at night, when tempoeratures are falling. No kidding, it helps!
Finally, some glass just does not take up resin like it should and gives tiny bubbles or air tracking along the fibers.
It looks really good still, though.

Re: second WRC Queen

Posted: Thu Oct 08, 2009 7:50 am
by vol
thanks BWD,
It is very difficult to make transparent surface without bubbles....
I think my mistake was to cold resin and room, that's should be 30c at list, warm resin is more thin.
board bottom is quite better than top, because I start from bottom, I put resin and fiber on to cover plastic first, than wood, than resin, fiber and top cover plastic, better solution would have been put first on top plastic resin and fiber than on to wood, next mistake was I use squeegee and make many foam in to layup.
do you think degasser will not help pull out bubbles during the press?
another reason, in the press there's 7 fire hoses, if I start press 1 middle hose, than 2 side, than second side...?

Re: second WRC Queen

Posted: Thu Oct 08, 2009 4:17 pm
by BWD
No experience with that kind of press, so I don't know if the hoses should get pressure at once or in sequence.
I have laminated a bunch of glass over wood, and the main problem I have seen is air inside the wood expanding and making bubbles during cure, like I was saying above.
Controlling the temperature profile helps.
You can also seal the wood with a coat of resin and let it cure mostly (up to 24h) to keep air inside the wood from expanding in bubbles.
It would be more work to combine vacuum bagging the laminate with a press, but vacuum bagging is another good way to get rid of bubbles....

Re: second WRC Queen

Posted: Thu Oct 08, 2009 8:00 pm
by pdkite
if you gradually increase the pressure in the hoses it will help stop bubbles and voids in your lamination.

so like start at 2 bar and slowly raise it up to your final pressure, say 8 bar. This helps gas escape.

do you have much rocker spring back with your cores? like you said the other board came out finished with 2.5cm, whats the rocker table set at? 3cm?

looking awesome. Third times a charm tho :thumb:

Re: second WRC Queen

Posted: Thu Oct 08, 2009 9:17 pm
by vol
thanks pdkite
you sure pressure until 8bar? it's about 40 tons on the board :o it looks like a TANK :naughty:
core spring back 5mm only, maybe because I put 2 layers of fiber and 1 extra stringer in the middle, or maybe I used another resin harder special for thermo curing, 4h curing cycle, when I take off board after 6h cooking, resin seemed very stiff

Re: second WRC Queen

Posted: Thu Oct 08, 2009 9:44 pm
by zfennell
hi vol,
the finish does look better,
but it always looked good :)

i'm not quite sure how you distribute the pressure from the pneumatic hose to the top of the board.
is there a simple soft release film or a stiffer panel?

i.e. do you get 'print - through' from the fire hose?


to be honest, once you place the board in the press, i dont believe there is any mechanish to remove bubbles from the laminate.
hand lams allow bubble to float and wet out.
vacuum bags provide an escape path with the addition of peel ply and breather cloth.
i'm not sure if any part of your press provides a similar function, which is probably why the ski/snowboard guys use solid top/bottom skins to dress up their product.

everybody has a favorite way to wet out the cloth. i don't think a squeegee is any worse than a roller.
in ether case over working the same spot is likely to introduce air.
in addition to BWDs suggestions you may consider :
using a short foam roller to distribute the resin.
spin the roller in the resin by hand to load the roller ( dont just roll it back and forth in the tray)
wet out the cloth by moving in one direction only ( again, not back and forth)
a soft (or thin edged) squeegee can help to wet the fibers ( enough pressure to keep the cloth down but not drag it)
you can also thin the resin a bit by warming it in a microwave for 15 sec.
(do this before you add hardener. )
do small batches and spread out larger volumes on a plate to keep heat level down (slower cure) and get mixed gas bubbles to the surface ( a foam brush can be used to drag bubbles to the side)

I suspect your core is flexible enough that the press is not really required to form the core.
if the bottom lam, comes out the nicest looking, you may want to do the top by hand.
or add some peel ply and breather to the top half of the press.

......or you can buy a sheet of .030" solid wood veneer to press on as a top sheet to cover the glass with something as nice looking as the cedar.

many flavors that have strength comparable to 1 ply of 6oz glass
cheaper than cedar and comes in 6ft x 2ft rolls from furniture makers.

just a thought.
it looks too good at the moment to lose any sleep.

regards,
-bill

Re: second WRC Queen

Posted: Fri Oct 09, 2009 8:34 am
by vol
Hi Bill
Between board and fire hoses I put 2 layers of 4mm press paper and thin metal 0.5mm, than A-PET plastic for smooth final, I guess press-paper a bit to flex, next time I'll try hardwood veneer. really no print - through from the fire hose, but when very shining surface you can see micro waves.
Thanks for the advice

Re: second WRC Queen

Posted: Fri Oct 09, 2009 8:16 pm
by pdkite
yup 40 000lbs would be good.

good luck on your next board - they look awesome.

Re: second WRC Queen

Posted: Tue Oct 05, 2010 4:31 pm
by vol
someone want board like this?
I was testing board one year, and I can say only one, PERFECT!
I was broken all boards in my kiteboarding because my riding style is aggressive, kiteloops, big jumps, hard landings but this board still alive :thumb:
just to say, rider make board for rider
short remind about board
full 8mm wood core from WRC (western red cedar) no one company do not made boards from WRC because wood is expensive.
WRC have very good dynamic characteristic, light and naturally waterproof, looks awesome!
H-glass - Hollow glass fibres. H-glass is a lower density fibre in comparison with a „solid“ E-glass or S-2 Glass, thus reducing the overall weight of cured laminates by up to 40 %!
stainless steel inserts
epoxy colored rails (more durable than ABS, easy to repair)
Hi quality epoxy resin
snowboard tech, high-pressure presses with thermal treatment

board will be without fins and straps
special promo price 150euro

Image