Pre-tensioned or Pre-cured Glass

[Isawsass]

I have noticed that a number of snowboard companies use "pre-tensioned" or Pre-Cured Glass. And I was wondering where people get this or do you pre cure it yourself?

[falls]

http://snowboardmaterials.com/pages/materials.htm
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[twizzstyle]

I used the precured/pretensioned fiberglass with carbon fiber stringers from Snowboard Materials a few years ago in a pair of skis. I did it as an experiment to see if the skis would be lighter - I made an identical pair at the same time with a normal layup.

The skis with the pretensioned stuff were quite a bit stiffer, and did ski great, but they were quite a bit heavier than the "normal" skis. I also had some minor delam in the tips, but that was likely just poor surface preparation on my part. The sheets come very smooth and glossy and need to be roughed up a bit.

[Isawsass]

Do they come from Snowboardmaterials in rolls or sheets i saw they sell it by the meter and it is pretty pricy. Would lay up on a pre bent cassette be harder than fabric, seems like it could cause shifting in lay up process? I found this too.
viewtopic.php?p=10174&sid=52c0b747db909 ... 021a78abdb

Off subject could some one explain to me again how to post pics I am bad with computers.

[Richuk]

Click 'post reply' and then hoover your cursor over 'Img*'. You'll see the instructions appear just above the message box, it starts 'Insert image'[/img]

[twizzstyle]

The material, just like dry fiberglass fabric, has very little bending stiffness until it is in a laminate. The core is what gives you bending stiffness. Bending stiffness is E * I, where E is the modulus of elasticity - effectively how stiff the material is when pulled - and I is a function of core thickness. This precured/pretensioned stuff just has a higher E than normal dry fiberglass, that's all.

I'd say the bending stiffness of the material alone is similar to base material, no worries doing it in a pre-bent cassette. I do all of my layups in the mold.

When I got it, it came as one long piece, rather than precut sheets.