Hello,
I’m a composites novice. About every 5 years I build something like a sailing dingy that calls for fiberglass and epoxy. It turns out okay. That said, I’m pretty handy. Jack of all trades.
I gave my high end ultra light weight carbon kayak (actually an outrigger canoe) an unwanted nose job. It’s constructed of prepreg carbon and cured in an autoclave. According to the advertisement it’s “high temp cured 4x modulus monocoque construction cured under high heat and pressure and covered in epoxy polyurethane marine paint.” Pretty fancy.
Long story short, the bow fell off my car and scrapped down the road, while the stern stayed attached to the car. I was pretty lucky. The only real damage that I can see is that the topside of the bow as ground off. I carry the boat upside down. No damage below the waterline.
I did some online research and thought I had a plan, which was to create a patch made out of multiple pieces of fiberglass cloth (not sure what weight) that were wetted to each other with the epoxy/hardener (West system 105 & 205), wet the inner surface of the kayak and then slide the patch which was laying over my finger like a wet napkin into the bow of the canoe so that there was about an inch and a half of overlap between the kayak and the wet cloth. Then I was going to use my finger or a paint brush handle to press the cloth to the kayak. When the patch cured, I was going to add more layers of cloth to the patch until I had something that matched the boats contours, then cover the patch with epoxy mixed with fairing compound yadda yadda.
Pictures attached.
Then it all went sideways. I did the prep, created a cardboard mock up of the patch. Cut about 5 pieces of thin cloth that I had lying around to laminate for the patch, wetted the inside of the kayak where the patch was going to be applied, laminated the cloth, waited until the patch was slightly tacky and tried to slide the sticky patch of unruly layers into that thin hole. The patch went into that hole like a cat goes into a bag. It was a mess. The patch ended up more like a wadded up piece of wet toilet paper. I pulled it out and walked away to lick my wounds.
My daydream was that the patch would harden enough, but not too much so that I could slide it in the hole without too much trouble. That said, I’m not sure if that was realistic or not. Also, during the process, I started getting nervous that if I waited too long the patch would suddenly harden and I’d be screwed.
Back to the drawing boards. Any and all advice is welcome.
Do I stick with a similar version of the plan?
-For example do one layer of the patch at a time?
-Try a single layer of heavier cloth?
-Try less epoxy on the patch?
-Let the patch harden more before sliding in the thin hole?
-Or is there some entirely different approach that’s reasonable?
While I don’t want to add a bunch of weight, I’m not trying to mimic the ultra light and stiff construction of the kayak. I simply want a sound patch.
Thanks in advance.