Repairs on Glass vs. Carbon-Kevlar

It has been posted on more then one occasion that repairing a Carbon-Kevlar boat is more difficult then repairing a Glass one. What different problems does one run into that make it more difficult? What different steps and or techniques does one have to use on a Carbon-Kevlar layup repair then they would use on the same repair job on a Glass hull?

if you have the money to buy c/k
then the difference in reparing isn’t significant. If glass is more affordable then you can be pleased the it’s a bit easier to repair.

Repairing boats
I have built and repaired wood and glass boats, but simply wanted to know why it would be any different repairing a Carbon-Kevlar hull then it would be a Glass one in case I ever was hit with the challenge. Dinged one of my glass boats last week (repairing it now) so that piqued my interest on what one might have to different if anything at all on repairing a Carbon-Kevlar hull. I assume it would it would be handled exactly the same way a glass hull would be, but if I am wrong, I would like to know what you would and should do differently. Just interested in the knowledge base.

Its the same
It is the same basic process to repair glass, Kevlar or carbon. You also could simply use glass for the repair of carbon or Kevlar, it will just result in a insignificantly heavier boat.


kevlar fuzzies
The dificulty is with exposed kevlar fibers. On the exterior you try to have an even patch with some bridging patch material over the fracture. On the interior it’s ok if the briding patch is thicker than the adjacent material. With regular glass that involves cleaning out the fracture and sanding through the gel coat and glass then grinding/sanding down the material for the gel coat to cover the patch.

Seems to me that with kevlar on the exterior it would help to have a compressing plastic sheet over the patching material to compress the fuzzies down. This is where vacuum over the patch might be necessary in concave areas.

Also it might require sanding down more with kevlar than just glass or carbon.

My only experience is trying to finish a carbon/kevlar seat and repairing a carbon kayak, haven’t done significant hull repairs.