So I know I'm a bit late to this party lol but I know a good way to mend carbon shafts.
Using CA glue is correct but add a little carbon from a pencil to the hole or ding first then drop some CA glue on it. This makes it an incredibly strong bond and is super hard. It will also blend colour better.
Using CA glue is correct but add a little carbon from a pencil to the hole or ding first then drop some CA glue on it. This makes it an incredibly strong bond and is super hard. It will also blend colour better.