Any guidance on carbon fiber types?

[kooks_only]

So, I'm looking to buy a bit of carbon fiber to put on the bottom of a few decks that I already have. My plan is to sand the bottom ply of maple off and then reinforce the deck with an epoxy and carbon fiber layer. I have noticed that CF cloth comes in a few "flavors." There is a K rating, a description of the type of weave, and a few other categories depending on the supplier. What is appropriate for a skateboard? At what point does the k rating reach "overkill?" I have been looking at triaxial weaves since this object is going to take a beating. If you can recommend a supplier while you're at it, great, but I am foremost concerned with the qualities that one should look for while browsing product. Thanks.

[Beau]

First off, I just want to preface this post by saying I don't have much experience with carbon fiber, but have done a little bit with it. The K-value relates to how many fibers are in a bundle, and it seems like the higher the K-value (or "tow"), the thicker the sheets are, and stiffer that one sheet of fabric can make a board. This is my understanding, based on what I'm seeing in carbon fiber stores online and based on the specs (the tensile strength generally increases with tow). It also seems like the larger tow fabrics are less flexible. I don't have enough experience to know if there's a maximum tow for making the bends on a board, but it would depend on how steep the board is. The weave pattern is also more of an aesthetic, based on my understanding - triaxial may be overkill for a board, unless you're trying to prevent cracking and flex from every direction. I recommend you check out this video I made for doing almost exactly what you're talking about, except I put it on the top, and explain why and how it worked out: https://youtu.be/5x9cxdH-cH0. I'm not a composites expert by any means, so I recommend you check with the supplier before purchasing and explain what you're doing. Fibre Glast (https://www.fibreglast.com/category/Carbon_Fiber) has come up for me in searches, but I haven't used them directly because I have a local source. If you can find a local source, that would be great, because you'd be able to feel and see all the different fabric types. Try to give Fiber Glast a call or stop by a local shop and explain what you're doing, and they'll be more helpful than I can be .

[kooks_only]

I recommend you check out this video I made for doing almost exactly what you're talking about, except I put it on the top, and explain why and how it worked out: https://youtu.be/5x9cxdH-cH0.

Oh, your video was the inspiration for this project! I totally stole your idea. Do you remember the k value of the stuff you used in the video? Was it biaxial?

I googled for a local source but there doesn't appear to be anything. I think I'm going to take your advice and just email a few online distributors (including fibreglast) and see if they can provide some guidance. If this works i'll start considering making a sandwich construction board (kind of like an overbuilt lib-tech). I am going to start with an old deck with a few cracks in it. I guess it's time to order the roarockit kit . Thanks for all your help!

[Beau]

Oh nice! Unfortunately, I don't know what the K-value was - a fiber composites engineer I knew gave me what he recommended (he also had experience applying carbon to boards), and I don't recall what it was. I do still have some of what I got from him - one is plain weave and the other is twill, and I think I used the twill. Both are biaxial.
Enjoy the build process, and let me know if you find out any other good info on fabric types and layup styles. I highly recommend the Roarockit kit - also, they have great customer service and can give you more advice on prepping the bag for working with epoxy resins and fiber composites that could save you some time/energy/money.
Share some pics/videos here as you build and experiment!