Carbon fiber how to: Part Two
So I went over the basic steps in part I. This article will cover more some more techniques for the more complicated shapes.
Ideally, you should not work with a piece that is more than ¼ turn or angle. Carbon fiber is relatively thick and will naturally wants to lay flat. If you are not using a vacuum bagging system or some kind of sandwich mold, chances are you will never get it right.
I have heard of people covering the original piece with saran wrap and then cover it with a few layers of epoxy. Once it’s cured remove the epoxy still in one piece, peel off the wrap, lay the carbon fiber as you would and slap the epoxy on top to hold it down like a sandwich. To be honest I have never tried doing that and probably never will so you’re more than welcome to take a crack at it.
Back to the techniques:
- Lay your fabric at a 45-degree angle instead of parallel to the piece that you’re covering. This will help the fabric go around curves and corners better because of the direction of the weave. You end up wasting more fabric this way but it also looks nicer.
- When wetting your original piece with epoxy, wait about 20 to 30 minutes or until the epoxy is tacky before laying your fabric on top of it. The tackiness will stick better and will help hold the fabric down to the surface.
- Work in a warm area to help decrease the cure time. Don’t put a blowtorch over it though just because you want to reduce the cure time to 5 minutes. You will end up overheating the whole piece and cause it to warp.
- Again, if you are working without any advanced equipments, just come back to the piece often after you’re done with the wet lay up and run your fingers through the surface in any area where the fabric might be floating.
- Make sure to soak the fabric completely and squeeze off any excess resin. Too much resin will cause it to sink below the fabric and cause it to float up. Don’t cheat on the first coat and try to make it too thick.
Another thing that you might want to try:
3M sells a cement spray adhesive that you can get at a hobby store or even at Staples for about $11. Spray your original piece with some cement and this stuff will hold your fabric down like no tomorrow. There are huge drawbacks with this method though. What are they? Well, epoxy eats through it like knife through butter. You can try waiting a few days for the cement to fully dry before wetting it with epoxy. The other big drawback is the insufficient amount of resin below the fabric. Since you’re practically gluing the fabric to the surface, and that does not leave a lot of room for the resin to get in. So what? So your carbon fiber will end up peeling off eventually. So what if it peels off eventually? Did I mention eventually as in a month or two?
pdf file - http://www.carbon-werks.com/articles/carbonfiber2.pdf
