Would the CF stuff up the repair cost much?
Doesn't everybody have some scrap carbonfiber cloth sitting around in their shop?
@Doug Briggs I end up with lots of spare fiber (when I cut cloth, I pull out one fiber to make a line to follow). I like about 4" lengths to make up my repair goo. 1/2" lengths are the standard for chopped fiber filler but for a hand done repair, I've done better longer. I like the clump effect
@cantunamunch describes for a repair as it gives multi axis strength. I have to engineer my cloth layout (some in line, some on the bias (45 degrees tilted) and unitdirectional for major loads) to carry the loads of my layup.
Some unitdirectional (sometimes advertised as tow) is hard to pull apart for fibers. (Some styles are great.) Crow foot style cloth is more flexible and fits contours better (and pulls apart to yield nice fibers). Some of my cloths seem to have different fiber size. I like small diameter fibers for repairs and complex shaped layups. The heavy fibers are easier for unitdirectional applications. Heavy seems to be less expensive (but it's all cheap compared to boron fibers).
Note that for this type of repair, fiberglass is pretty good also. Probably not a gram of weight difference and glass is quite strong. If you can find small strand flexible glass cloth to pull apart, that works really well. I use the carbon for repairs because I have it sitting around but I've done a lot of repairs with glass too.
Note, glass is very strong in compression and it can be tougher than carbon. Arguably a better repair choice.
Don't use Kevlar. It doesn't bond well to the resins and is impossible to sand for a finish. Not good for the home workshop.
Eric