How do you repair a plastic kayak?

Question

So roughly a month ago my other half and I brought ourselves each a SOT plastic kayak, we've been out on the water for maybe 2 hours total paddling time, but mine filled up with water.

We found a hole, approx. 1cm by 0.4cm, in the seam of the plastic in one of the two rear drainage holes, too small to get your hand down easily. I am currently talking to the manufacturer about a replacement.

However this has lead me to wonder (outside of warranty) how would I go about repairing a hole in a plastic kayak? Varied sized holes, and temporary and permanent fixes, I understand will vary.

Answer 1

The main issue with repairing plastic hulls is that is that most adhesives don't bond very well to the plastic. For temporary repairs duct tape is the way to go. Its quite adhesive and waterproof. If the hole is too big use the duct tape to secure something else waterproof (e.g plyboard or plastic) in place. If possible try and do both inside and out.

If you want to do a permanent repair there seem to be two options:

Repair in a similar way to fiberglass. I.e. Sand the surrounding area and apply a fiberglass patch and epoxy. The one significant difference is that the area around the hole should be flame treated before applying the patch by lightly heating with a propane torch or similar. This helps the epoxy bond to the surface. Be careful not to burn your boat though.

The alternative, more conventional, way is to melt/weld more plastic into the hole. I suspect this is what a professional would do if you asked them to do the repair. Here's another good article on it. For smallish holes you want to get some polyethylene welding rod (presuming the boat is polyethylene) for large holes you need to get a patch. The basic idea is to melt the rod into the hole using a hot air gun or hot metal. As you've melted two of the same material together this repair should be very strong.

Disclaimer: I'm mainly a dinghy sailor so haven't actually repaired any plastic hulls. This is just based on my general understanding of boat repair and reading the internet.

Answer 2

I've seen people use a soldering iron and a piece kf abs plastic to repair tears in the hull but the best answer is short and simple to use for small holes: epoxy putty.

just follow instructions on the packaging, fill the hole with a small (few mm) overlap inside and out and if you want sand down when hard and paint.

Answer 3

It's quite common to melt in some plastic - but be sure to get the same as the boat is made of. Most are PE so try to get some of that -- avoid ABS. Kits are available (random web example). The general recommendation among people I know who've done this is to use a hot air gun rather than a naked flame. You can also overfill a touch and smooth down later. The repair will be pretty good for flat-water use, but will always be a weak spot to be wary of in significant white water and to a lesser extent surf. As you've got SOTs I'm guessing/hoping you're not doing much if any river-running so you should be fine. Be sure to get all the water out first though, you don't want to trap it in there, and make sure the surface is clean before repairing it (e.g. of salt if you've been in the sea).

Answer 4

For from upto small leak holes to upto coin-sized holes, You can possibly use a Duct tape on the both sides. One more thing to add between the Duct Tape's point of contact is a filler like Some local Epoxy Compound product, or worst case a Chewing Gum (Chewed one :D).

For a crack, you might just get it fixed by a Duct Tape.

Answer 5

Shoe glue to fill the hole"let it dry". Then JB weld spread over a area 20 times the size of the hole. Or shoe glue then aluminum sheet, 4 bolts and cover with jb weld on both sides.