How bad is Biax?
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- Mista Sparkle
- Posts: 5
- Joined: Thu Jan 01, 2015 8:19 pm
How bad is Biax?
I got a hundred yards or so of biax glass ~4-8" wide for free, so I'm wondering how much worse it tends to behave than triax?
I'm in the process of building a pair of big mountain skis, not decided on dimensions yet but something moderately wide... I have a yard of triax left over that I figure that i could mix in, but not enough to do the whole pair.
Has anyone done a side by side comparison of the 2 types of glass in an equivalent layup?
I'm in the process of building a pair of big mountain skis, not decided on dimensions yet but something moderately wide... I have a yard of triax left over that I figure that i could mix in, but not enough to do the whole pair.
Has anyone done a side by side comparison of the 2 types of glass in an equivalent layup?
- MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
biax only in an adult ski would be way too soft, there is no fiber in the longitudinal axis.
If you do biax only you'd need to add some unidirectional carbon or fiberglass to give it some strength in the 0 axis.
I have used biax only when I build very small skis for my kids and even then I add some carbon tow longitudinally.
If you do biax only you'd need to add some unidirectional carbon or fiberglass to give it some strength in the 0 axis.
I have used biax only when I build very small skis for my kids and even then I add some carbon tow longitudinally.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
www.Whiteroomcustomskis.com
As an addition to what has already been said, you need to understand what the various strand directions are doing in your ski or board build.
The strands running lengthways are there to add stiffness and strength when a ski is being bent straight up or down. The strands running at 45 degrees (Probably the biax cloth you have) are mainly there to help increase the tortional rigidity or twist of your skis.
I combine biax and uni directional fiberglass when making longboards so you could easily do the same.
The strands running lengthways are there to add stiffness and strength when a ski is being bent straight up or down. The strands running at 45 degrees (Probably the biax cloth you have) are mainly there to help increase the tortional rigidity or twist of your skis.
I combine biax and uni directional fiberglass when making longboards so you could easily do the same.
I am nobody. Nobody's perfect, so I must be perfect.
- Mista Sparkle
- Posts: 5
- Joined: Thu Jan 01, 2015 8:19 pm
It's actually a plain weave, probably in the range of 8 OZ glass. If nothing else, I imagine it would be nice and clear...
It's ~.011" thick~16tpi something maybe like this the 7-1/2Oz fabris(Part # - 243, 244) at fiberglast . I figure it should be reasonably comparable if I build it to an equivalent weight so ~3 layers... I could thin the core up a just a touch to reduce its stiffness along the ski and the slight excess of glass may be able to make up for a slight loss in torsional rigidity... Gotta work a bit more on my calculator...
I'd post some photos but It looks like I need a few more posts.
-Mista
It's ~.011" thick~16tpi something maybe like this the 7-1/2Oz fabris(Part # - 243, 244) at fiberglast . I figure it should be reasonably comparable if I build it to an equivalent weight so ~3 layers... I could thin the core up a just a touch to reduce its stiffness along the ski and the slight excess of glass may be able to make up for a slight loss in torsional rigidity... Gotta work a bit more on my calculator...
I'd post some photos but It looks like I need a few more posts.
-Mista
- Mista Sparkle
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- Joined: Thu Jan 01, 2015 8:19 pm
- MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
What weight is the carbon tow? I usually use 12k tow. 4-8 of these in the 0 axis top and bottom definitely stiffens things some.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
www.Whiteroomcustomskis.com
- Mista Sparkle
- Posts: 5
- Joined: Thu Jan 01, 2015 8:19 pm
Hmm, Well, it's too narrow to lay at an angle for any reasonable length...MontuckyMadman wrote:You coild orient the plain weave on the bias and use the tow on the 0. Woild be like triaxial 45/45 0.
What I suppose I could do is use a couple layers and heavily skew the fabric so one layer would act as -45/0 and the next would act as 0/45... This seems reasonable. Maybe even if it's light enough for 3 layers, it would end up being -45,0,0,45,0,90. does that seem like excessive 0?
Not sure on the weight of the tow, I'll look into that.
or you could just buy some 22oz triax from Jamestown distributors...free shipping on orders over $50 until the end of the day tomorrow
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
www.Whiteroomcustomskis.com
- Mista Sparkle
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- Joined: Thu Jan 01, 2015 8:19 pm
- MontuckyMadman
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- Joined: Fri Jun 20, 2008 9:41 pm
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Or as said, buy some Unidirectional fiberglass and combine it..
Or go exotic and add some Carbon Unidirectional.
I bought some Carbon Unidirectioal matting, and because it is so expensive I cut it into about 1 cm strips and add it where I want some extra stiffness in the skis. Means you don't have any waste.
Or go exotic and add some Carbon Unidirectional.
I bought some Carbon Unidirectioal matting, and because it is so expensive I cut it into about 1 cm strips and add it where I want some extra stiffness in the skis. Means you don't have any waste.
I am nobody. Nobody's perfect, so I must be perfect.