Fiberglass cloth question

[Fanman]

 Any thoughts on using a 2x2 twill vs. plane weave cloth?
Draping, strength and usability?
Thx,

[PonoBill]

Twill is always stronger and more shapable. The weave is looser so the strands move more readily and their run is straighter so the fibers are stronger. I mostly buy twill but always wind up doing most hairbrained projects with straight weave because I use the twill up on intentional projects and all that's left is straight weave.

Satin and twill unravel easier, and are harder to cut precisely, especially satin, which is 3 or more strands passing over each thread set. Modified twill is 2 by 2. Satin is the strongest and most easily shaped, but can be a pain in the ass to handle since it falls apart so easily.

[Fanman]

Thanks Pono 🤙🏼

[PonoBill]

Any reinforcing cloth gets strength from fibers that align with the bending force, but if the fibers are wavy--as they are in a straight weave, they have to straighten before they reach maximum stiffness. Easy to notice with carbon, but obvious also with glass once you pay attention. Flat weaves can reach stiffness quicker and there are some fancy semi-unidirectional fibers where one fiber direction waves up and down, securing a second fiber that stays straight. High skip satin--like five or more strands skipped is almost as good, but turns back to a mass of threads if you handle it much. I think one reason why Carbon Kevlar weaves are sometimes used is that after initial tension, the carbon fibers stay pretty straight, but the stretched Kevlar stays wavy. At least that's what a somewhat goofy but generally knowledgeable friend told me. I saw a carbon kevlar board a few years ago with the kevlar running longitudinally. I think the builder just thought it was pretty.