In the previous Kingfisher video I mentioned that water keeps getting into the front hatch. I tried window weatherstripping, stacked in several layers — it ended up working like a submarine airlock, but it didn’t help. After another fishing trip, once it was clear the leak was still there, I finally sat down and went looking for the source — and found it.

Cracks at the pedal-drive mount

Turns out the leak isn’t coming through the hatch lid — it’s coming through the hull itself, right where the pedal drive is mounted. There are two matching cracks, one on each side. The whole block flexes at that point, and the plastic has already developed a visible fold. To show the problem on camera, I clamped the kayak in the water and used my hands to simulate the pressure your legs put on the pedals — you can see the whole assembly flex. Interestingly, the makeshift fix I rigged up earlier — a temporary support under the drive’s screw — turned out not to be useless: with it in place, most of that play was gone.

I watched some videos on welding polyethylene and checked prices at a local repair shop — around €130 an hour. I decided to hold off on welding for now: the kayak is fairly flexible, so it’s unlikely to crack outright from hitting a rock, even though there’s clearly stress at this point. Instead — a quick fix with a specialized adhesive that behaves a lot like sealant.

Quick repair: degreasing and patches

Before gluing, I scraped both problem spots with a knife — the cracks go all the way through, the plastic is almost see-through there in places — and degreased the surface. I didn’t overthink the adhesive choice: asked ChatGPT what would work on both the hull plastic and the joint material, and ended up with T-Rex Power. Applied it as patches — it’s quite tacky, and in places it even squeezed through to the other side of the crack, a good sign it went all the way through. Just in case, I smeared sealant on the back side too, where drops were starting to show through as well. Now it’s just waiting for it to cure without the patches peeling off early.

3D scan for a future upgrade

While the glue was curing, I decided not to stop at the patch and scan the whole assembly in 3D to get control measurements for a proper upgrade. The idea is to 3D print a reinforcing “heel” that sits under the mounting plates (I saw a similar solution from another builder) — a foot on a post that wedges in place and stops the block from flexing at all. The one downside is that the heel will stick up slightly above the kayak’s profile during transport, but that seems livable.

This was my first time scanning anything, using an app like Polycam — had to remove the pedal so it wouldn’t get in the way. I ran a few scans: the longest tried to capture the interior too, another was a quick scan with the pedals still attached (deleted in the end, too messy), and one more was just a rough blank for spotting gross errors. I checked accuracy against a tape measure: the mounting plate is about 140mm wide, 25mm thick, the metal fitting roughly 90-100mm, the hole 110mm, the wall 180mm. Honest verdict: fairly low-poly, with a couple centimeters of error right at the joint I actually need, though the geometry — angles, distances — came out noticeably more accurate than the baked textures, dimensions within about half a centimeter. Good enough for a rough first pass toward the real part, even if the app itself felt a bit rough around the edges.

What’s next

The adhesive packaging says it sets in one second, so the patches should be ready well before tomorrow’s outing. If you’ve got experience with a similar repair — welding polyethylene or anything else — share it in the comments, it would be useful. And curious to hear what you think of this video format.