I’ve got a friend who was given a free roll of 50" wide carbon by his uncle, who’s had it stored in a barn for years.
I checked it out and it looks about the same thickness as the 5.6oz I’ve been buying from my supplier, but it feels soft and flimsy. The carbon I’ve been using, by compaision, is fairly stiff and is slow to droop over the board when I roll it out.
Any idea why they are so different? Could it be a coating on one and not the other?
I’m concerned if I use my friends free carbon, my board may not be as sitff?
You know the yellow yarn they sew down the edge of a roll to keep it from fraying, well this free carbon has that yellow yarn running down the middle of the roll too! And that may be why nobody wanted it. For me, it’s fine because I build them like a windsurfer, vac bagged and painted white.
It sounds like you might have a roll of the good stuff, except for the additional yellow stitch locking fiber down the middle…
All the high quality 5.6oz. Carbon I used to buy was soft ( a subjective observation,or perhaps better said “as soft as carbon can be”) and was as easy to work with as regular glass…Yours might be a 2x2 twill and these seem to lie smoother, have less crimp, and are very nice looking…
I’ve had some really stiff 5.6oz. plain weave carbon that looks like pure crap (cosmetics) with an uneven weave… I still use it. but only for patches hidden under HD deck foam skins…
Just because the stuff you have seems soft and easy to work with doesn’t mean it’s not good carbon…It might be just the right mix for a nice carbon surfboard…
Take Bill up on his offer, he knows what he’s talking about…Although you might also want to send a patch without epoxy, as that’s a good way to tell…
Check out the carbon in this link, the top is plain weave, and the bottom is twill… If you were going for strong ,easy to form and highly cosmetic, which would you chose??
The twill is stronger because it's woven 2 over, 2under and is much more like 2 loosly woven uni-directionals.... The plain weave is one over one under, and results in more "crimp" which is short for the bend the weave has to make going under and over the perpendicular strands)....The twill is "softer" or more formable simply because the weave is more relaxed in it's construction...
BTW. I ain't no scientist,,,, just a simple Plumber... But some things are as plain as the nose on your face...;)
The kevlar fiber running down the middle is there not only to ‘lock’ down the fiber, but to orient the fibers uniformly. Stiffness of the fabric is not a bad thing for this also helps keep the cloth uniform when applying. Softer fabrics while easier to saturate tend to move and can leave an imperfect appearance which one;s eyes tend to focus on. There is much more that can be said.
The kevlar fiber running down the middle is there not only to ‘lock’ down the fiber, but to orient the fibers uniformly. Stiffness of the fabric is not a bad thing for this also helps keep the cloth uniform when applying. Softer fabrics while easier to saturate tend to move and can leave an imperfect appearance which one;s eyes tend to focus on. There is much more that can be said.
the fact that it is black is a pretty good indication that it is carbon.
even the lower grade fabrics will be much stiffer than glass.
however, there is never a guarantee that your lam will be stronger than glass.
i'm not sure what sizing they use on carbon, but extended storage in the barn (dirt,dust, water, mouse turds) can easily impair the wet-out when you lam your board.
regardless, of how you proceed a small test patch would be good insurance against a major waste of time and materials.
I’ve bought 50" wide and 60" wide Carbon , and I’ve never seen the locking stitch down the center of these widths, cosmeticly messing up the bolt of cloth…
I’ve seen it on the extreme outside edges of the cloth, but not down the middle… Perhaps this 50" roll was meant to be factory cut to only 25" wide.??
I have an older roll that I bought from a retired aerospace engineer. It has fine kevlar lock stitch/tracers in a grid pattern throughout the width and length of the material. It's visible after laminating but you have to look pretty close. I'm not sweating the cosmetics since the price was right.