Montucky Skis

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doughboyshredder
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Post by doughboyshredder »

the only board I ever left to cool in the press ended up with a warped base. None of the others ever have.
OAC
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Post by OAC »

So you have build 20 boards now?
doughboyshredder
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Post by doughboyshredder »

Thousands actually.
In my own press, yeah about 20.
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MontuckyMadman
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Post by MontuckyMadman »

I think 180 is too hot and is causing some base warp also.
sammer wrote: I'm still a tang on top guy.
OAC
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Post by OAC »

If you're using "room temp" epoxy it's much. Otherwise it shouldn't be a problem at 180.
Are you using that QCM stuff? Doesn't they have any advise?
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MontuckyMadman
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Post by MontuckyMadman »

no its a heat cure epoxy. Supersap.
So you pull them at 175F hot?
Seems like more warp could come from that. Don't they have water cooling presses for production?
sammer wrote: I'm still a tang on top guy.
doughboyshredder
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Post by doughboyshredder »

MontuckyMadman wrote:no its a heat cure epoxy. Supersap.
So you pull them at 175F hot?
Seems like more warp could come from that. Don't they have water cooling presses for production?
The water cooling is to cool the press before the next set is put in the press.

pull the board (skis) hot, pull them off the aluminum sheet and set on a flat surface to cool down.
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falls
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Post by falls »

how hot do you pull them? with gloves on after the recommended time at temp or do you let them cool a bit first?
I've only pressed two sets with heat. Left them overnight to cool.
The first pair were edge high (but I also didn't have a rebate in the core for the edge teeth). This second pair seems maybe to be base high (convex). Go figure?!
Don't wait up, I'm off to kill Summer....
doughboyshredder
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Post by doughboyshredder »

I pull them as soon as they are done cooking. NO cool down under pressure.

When I worked in production we had cooling racks. We would pull the boards, check the camber, and then put them in the racks and either increase or decrease the camber as necessary while cooling.

I pull them out and put them on a perfectly flat table that I have and let them cool down there.
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Brazen
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Post by Brazen »

Hey. Are these worth it? Are those mountains ride-able?

http://www.theknollsathillcrest.com/hom ... .php#avens
"86% of the time it works 100% of the time".
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Brazen
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Post by Brazen »

NO amount of pulling when hot OR cold makes the difference. The way for a "perfectly" flat base is in the press. If there are issues, varying in size (I'm talking 5/1000ths) it has fk all to do with WHEN you pull, and everything to do with your molds. I'm just sayin'. If I get a closer +/- .000 base after cooling, then that's what I mean. It doesn't mean it's the best way or the only way to do it. I remain quite sure that given hotpulls, lack of consideration for the different responses we have in materials AND our BTSR can ALL be engineered out in a "perfect" mold. Period.
"86% of the time it works 100% of the time".
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MontuckyMadman
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Post by MontuckyMadman »

Brazen wrote:Hey. Are these worth it? Are those mountains ride-able?
Nice trail riding jogging and that area, would be dope to sail ski or para ski or whatever with all the wind.

Bridger is 15 min from there and here.
sammer wrote: I'm still a tang on top guy.
doughboyshredder
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Post by doughboyshredder »

Brazen wrote:NO amount of pulling when hot OR cold makes the difference. The way for a "perfectly" flat base is in the press. If there are issues, varying in size (I'm talking 5/1000ths) it has fk all to do with WHEN you pull, and everything to do with your molds. I'm just sayin'. If I get a closer +/- .000 base after cooling, then that's what I mean. It doesn't mean it's the best way or the only way to do it. I remain quite sure that given hotpulls, lack of consideration for the different responses we have in materials AND our BTSR can ALL be engineered out in a "perfect" mold. Period.
Sorry, but you are wrong.

You want proof? Build a test board with one diagonal strip of carbon fiber. I guarantee you that your board will be twisted.

Fact is that different material expands and contracts differently when heated and cooled.

A slow ramp down in heat as happens when you leave the laminate to cool under pressure exacerbates this problem.

Leaving the board in the press while the press cools down is NOT beneficial in anyway whatsoever. There is no reason to do it.
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Brazen
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Post by Brazen »

Haha, I'm glad you're back :D. Let's just say, that for whatever insane reason, I decide to place a single stringer diagonally...you're telling me I can't mute the fault out by engineering my mold to compensate? Or that time under pressure and process temperatures don't effect it? Maybe I should have invested all my money in cats...
"86% of the time it works 100% of the time".
doughboyshredder
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Joined: Mon Sep 17, 2007 7:37 pm

Post by doughboyshredder »

Brazen wrote:Haha, I'm glad you're back :D. Let's just say, that for whatever insane reason, I decide to place a single stringer diagonally...you're telling me I can't mute the fault out by engineering my mold to compensate? Or that time under pressure and process temperatures don't effect it? Maybe I should have invested all my money in cats...
I'm saying if you put it in a "perfect" mold, that it would come out twisted. Of course if you twisted your mold the exact right amount in the opposite direct you could compensate for the problem.

I'm also saying that time under pressure exacerbates the problem.

Take it out while it's still hot, and the parts that want to contract faster have the opportunity to contract without affecting the entire laminate. Keep them under pressure and the parts that want to contract create tension on the other parts and then when they are finally cooled off and released from the press.... voila... instant imperfection. As we all know the epoxy is not completely cured until a few days or a week after pressing. The material is still somewhat pliable when hot. Keeping it under pressure doesn't allow for minor variances in contraction during cooling.
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