Hand Laying Carbon Fiber Cloth in a Kayak

Laying carbon fiber is not that different from fiberglass accept that it is black, and stays black. Where fiberglass starts white and becomes transparent when saturated with epoxy, carbon fiber stays opaque, so it can be tricky to tell if it is fully saturated. Where bubbles under glass are clearly visible you may not find bubble under carbon fiber until after the epoxy has set up. You may actually never find a bubble.

There are more videos of building kayaks available here.

I am using 6 ounce carbon fiber here. Because it is a heavier cloth than the 4 ounce glass I am using it will need more resin. And since carbon is less dense than glass, the same weight cloth is thicker than fiberglass cloth would be, this means it needs even more resin. If you have calibrated yourself to understand how much resin is needed to fill an area, you will need to apply a lot more resin than you are used to.

I am rolling on the resin with a paint roller so I don't have to move the resin around through the cloth as much as if I dumped and spread.

I have the shop temperature turned up high (80° F, 27) to keep the viscosity of the resin low and aid penetration into the cloth. A consequense of this is the resin sets up fast. Therefore I am working on small areas at a time, wetting out the fabric spreading out the resin and then scraping off the excess.

The only way to tell if the fabric is fully saturated is to inspect it carefully. Low, glancing light will help highlight bubbles which usually indicate under saturated cloth.  A blacker, less shiny spot is also an indication of insufficient resin in the cloth. If the cloth lifts easily off the surface while rolling on resin, that is a good sign that it has not yet wetted all the way through to the wood.