Why does it seen like 3K prepreg twill is more popular than the 6k? Is it because of the surface reason? most of the dry 3k twill all have gap between the tows, does prepreg 3k eliminate those gaps? I am about to buy some prepreg but I am contemplating between 3k and 6k and mainly because of the gaps between the tows and less lay up, structural is not my main concern right now.
Anyone who’ve used both?
I’ve kinda also wondered why 3k is more popular. I think for one it conforms to irregular surfaces better than 6k. Plus I think its harder to get a good pin hole less surface with 6k.
I’m not speaking from experience only what I have read.
anyone else have any input? Thanks
Most prefer 3k because it is the “look” everybody wants. Not to mention that it conforms better. There are different thread densities with 3k. There is 190gsm or I’ve seen 270 gsm. But to get a nice 2X2 twill “look” I prefer a 220 gsm. You can find these at Soller composites.
I’ve used both, because we had both in the freezer. I’ve used 24k prepregs as well. But I’m special 
which one do you like more? or are they the same to you (cosmetic)?
I think the 3K fabrics are used more often because they are more readily available. Hexcel has their 282 and 284 fabrics a(nd other weavers offsets to these) which are spec’ed into many different aerospace programs, and have been for many years. Because of this weavers are more likely to have 3K fabrics available for other applications. Plus the finer tow size makes the twill or plain weave look cooler… 1K wovens are pretty cool looking too, but not for the $$.
I like larger tows. I’m a fan of the spreadtow stuff as well. But really, for cosmetics, anything carbon is good…anything bigger, and more exotic a weave (plains vs 2x2 twill vs 4x4 twill, vs custom woven) is even better.
Agree, easier to manipulate the 3K, readily available, and it’s affordable. Only in really high end jobs where durability and strength count do we see guys going with the 6K. It just happens that most people are hobbyists making projects that they have a budget to stick to…and they want it to look cool because let’s face it, carbon fiber looks very cool.