When I was at my parents place, I went kayaking with my mom and brother. It was fun as always, but about halfway across the lake, Tyler’s kayak was seriously slowing down. When we pulled into the island to check out the kayak, it had a fairly substantial leak. Some bailing and a hard kayak back (for Tyler ), we got in safely but then we needed to fix the kayak.
Upon inspection, there were two large cracks right under the seat and that was indeed where the water was coming in from. The kayaks are rotomolded polyethylene, so we couldn’t use the traditional epoxy and cloth repair; we had to use molten plastics instead. It turns out that most boating stores sell polyethylene rods just for that purpose.
The crack before fixing. It doesn’t look that big, but it leaked a fair bit.
Step one is prepping the surface: drill a hole at the edge of the crack to retard future crack growth, sand down the crack to be smooth, and dry the area.
And the crack halfway through repair. I forgot to drill the holes, so it took two passes.
Step two is applying the polyethylene. The best tool is a large soldering iron or other non-flame heat source, but I used a butane torch and was careful to not catch the plastic on fire. You want to heat up the plastic on the crack and the plastic rod, then press the plastic rod into the crack. You want to stay just below the melting point and limit total heat input to the boat to minimize thinning of the plastic.
And post repair. It looks OK; if I used a soldering iron you wouldn’t get the burn marks.
Step 3 is cleaning up: if you don’t have time to clean up, you don’t have time to do the job.:) I’m trying to be better about this.
Overall, the repair worked quite well. 5 months in now and it is still functional.