Fiberglass comparisons 22 vs 19 oz

[vinman]

So I can find some 19oz vectorply glass for a decent price with a small local commercial builder. But my problem is I usually use 22 oz vectorply glass.
The torsional fibers are the same in both fabrics, just the longitudinal fibers on the 19 are lighter.

I know this means not as longitudinally stiff as long as the same core profile is used.

I guess my question is would adding some carbon strings, full lengths bundles pulled from weaved carbon fabric, make up for this? My thought is yes, but how many strings... Probably depends on the weight of the carbon...which I'm not sure of.

My thought right now is maybe 2-4 both top and bottom would beef up the 19 enough to give me a close approximation of the 22 oz glass.

This fabric also has basalt running at 90 deg and I could probably use that as well... Maybe a couple bundles of each....


Thought? I'm just brainstorming here so any ideas this are welcome.

I guess it may come down to trial and error but throw some ideas in please.

[Sherpa Burns]

If you are thinking about 2-4 threads of CF both top and bottom, why not just use a 1 inch strip of the CF either above or below? This would be a lot faster and easier than separating individual strands. Also, a 1 or 2 inch strip of CF in a set of skis adds a lot of life to the flex.
Were you thinking of pulling the basalt and using longitudinally rather than CF or wondering if the 90 degree basalt would stiffen it up? The 90 degree basalt is pretty useless in skis due to the already narrow width, but would come in handy in a snowboard.

[vinman]

I could probably use a 1 -2 inch strip I guess. I'm more afraid of making the ski too stiff than not stiff enough. I guess this was the reason to pull strands out. Plus I don't have to worry about adding too much stack height to my layup and creating a convex base problem like Twizz was having due to the finite thickness of the carbon fabric.

And like you said the basalt doesnt do anything for me but add wt.

I was thinking of using the basalt in the rockers only to stiffen specifically that section.

[sammer]

OK so here's what you need to know.

I went from 22oz vectorply to the 19oz.
Using 2 strands of 24k carbon fiber
http://www.fibreglast.com/product/24K_C ... w_2293/156
is close to the same.
Flexing a ski it's hard to tell the difference.

Using 4 strands is obviously stiffer you can feel it!

If I'm looking for the extra stiffness I'll use 2 or 3 strands above and below the core.
But most times I'm just using a couple above the core.
Be aware I don't really have heat, just an old electric blanket ( like on your gramas bed) so probably 130- 140 max, so YMMV!

sam

[vinman]

Right on Sam, way to kill it, thanks. Its good to know I was in the ball park. I knew someone here would have the answer for me. This will save me a bunch of $ to not have to pay the shipping plus getting a decent price.

I think I'll with 2 strings above and 2 below and adjust from there. I'm might even just put the basalt fibers along the running length. I've got some good options now..ideas are spinning around in my skull.

[vinman]

So the 19 glass is really 19.7 glass and the 22 is really 23.4 glass.

The only carbon-basalt fabric I can find on the web is 3K carbon-basalt 2x2 twill.

I figure weighing out the carbon would at least give me some sort of idea on how much to add instead of an arbitrary 2-4 strands.....

So I was thinking that weighing out 1.5 oz of carbon would just about make up for the difference in the long glass fibers? Does this make sense since I really don't have specs on the carbon? I bought it as a remnant on here.

Does anyone have any experience with the basalt fabric? From what I read it is very equivalent to glass and greener.