I have a carbon fiber race canoe that was originally constructed using vinyl ester. The hull is being patched using epoxy and carbon and then refinished with and epoxy/ graphite mixture.  I have seen information the mentions a wash/ surface prep is required prior to using the epoxy.  I haven't been able to locate any information on what is required for the prep.  THank you in advance for any and all assistance.

Gary

Vinyl ester is easier to bond to than epoxy, it has quite an active surface energy. But really I treat all panels the same, whether I'm bonding to polyester/vinyl ester/epoxy/phenolic/plastic, etc. Same prep-work, then an appropriate adhesive/resin. Plastics can be difficult, but everything else works provided the prep is right and the adhesive/resin is appropriate.