Fixing a plastic (polyethylene) kayak with a hole in it

I work for Pamlico Sea Base ( http://pamlicoseabase.org ) as a sea kayaking guide. One of our trailers is built for canoes and doesn't have fenders over the tires. Unfortunately someone wasn't paying attention when loading it with kayaks and the sides of a few boats sat on the tire for a 2 hour trip. We now have 3 boats with gaping holes in them.

It isn't very likely that you'll have a kayak with such a large hole, but whatever the size, here's how to fix it.

Step 1: Materials and Tools

You'll need:
1. some sort of patch. we had an old trashed boat we could cut up. The only other plastic I know that will stick well are those big blue 50 gallon drum/barrels. Make sure you wash it out well!

2. gloves

3. heat gun (I used a blow torch which isn't great but works)

4. a water bottle (for safety reasons)

5. a large metal spoon or putty knife

6. a pair of pliers

Comments

[dmcghie]

so question, if your not in a time crunch situation wouldnt it be easier to fix it with a fiber glass patch would need a few people to do it but i think it would actually make the area tough enough (i assume the patched area wasnt as strong as the rest of the boat) to withstand troubles on the water??

[crickle321]

This is a DIY project with the true spirit of DIY. Well done!

[dfrelow]

how did you get that enormous hole?

[dunnman]

I am curious as to whether to cut the patch to the exact size of the hole or would it be better to cut the patch oversize and sort of stick it over the hole and then smooth out the edges inside and out?

[WayfinderAli]

If you have the heat gun and plastic welding sticks (plastic filler rods), you can cut the patch to the exact size and shape and then use the plastic welder and plastic welding sticks to seal the seam. If you don't have that equipment (which I didn't) the only way to ensure that the patch will stay in place, keep water out, and withstand use and abuse, is to cut it larger than the hole and then smooth out the edges.
If you get the plastic filler rods, you'll have to have someone hold the patch in place or duct tape it in place and work slowly.

[dasgemuse]

the proper way is to use a heat gun and plastic "filler rods" it will look 10x better

[WayfinderAli]

I've used the filler rods on other boats and they worked really well for holes but I don't think it would work very well with such a gaping hole. If I had been able to cut a plastic patch that was exactly the same size and shape as the hole, the filler rods would have worked well. Also this instructable was made with the few resources I had on hand. I had two days to get 3 boats fixed and back out on the water.

[dasgemuse]

i of course meant to use a patch along with filler rods. lol

[WayfinderAli]

You're right, it would look way better with filler rods. But wouldn't the patch have to be just about perfect in shape? I hope this doesn't happen again, but it could happen again this summer, and it might be worth getting the rods.

[R2D2Laboratory]

i would just buy a new one :)

[WayfinderAli]

Unfortunately they're pretty pricey. around $1,400 retail and the Boy Scouts (who own and operate Pamlico Sea Base) don't have enough money to go buy new stuff when old stuff gets damaged.

[kevinlee]

I use a heat lamp and pretty much the same process (we use powdered resin) to repair fuel cells on tanks at work. Gallon milk jugs will also melt and blend for fixing cracks. Just grind out the crack and melt it in.

[CaseyCase]

I'd suggest using a heat gun to weld plastic instead of a torch, better fine adjustment of the temperature.

[WayfinderAli]

After fixing another boat recently, you are totally right. A heat gun is WAY better. Although I don't know if I could have gotten the patch melted enough to make it stick with a heat gun. It is really easy to burn a hole through a boat with a torch.

[mackamitsu]

You can also use a smaller torch. I bought a small MAPP gas welder kit for fixing plastic, it is easier to control due to its size. Its also cheaper then a full size torch and bottle set up. I'd think even a plumbing torch set up would do the trick.

[WayfinderAli]

That torch was a pain to use. It was what camp already had sitting around so it was what I used. In hindsight, a heat gun is probably the way to go. Although I think its hard to get a big patch to melt enough with a heat gun to make it stick, so in that case I think your smaller torch idea would be the way to go.

[AntMan232]

If it was me, i'd duck tape over it but, if you really want to patch it...

[crapflinger]

i used to work at an outdoor outfitters, and we sold kayaks. some of the kayak manufacturers (blackwater, dagger, etc..) have a policy in place to keep shipping down for blem boat returns (blemished), instead of shipping the boat back, you just have to cut out the serial number plate and ship it back, then they ship you a boat. this tends to leave you with a gaping hole in the boat.

the guy that owned this shop wasn't exactly the most ethical guy, so he'd typically cut the numbers out of at least one boat out of every shipment, then we would have to patch the boats as cheaply as possible and then they would sell the boats at a discount (if you sell a $1,000 dollar boat for $500, and you technically never paid for that boat, well then that's 100% profit). we would use pieces cut from 55 gallon plastic drums.

[lemonie]

Did you lose rubber from the trailer-tyres?

L

[WayfinderAli]

The boats that didn't have such complete holes, that is that had some plastic left at the hole site, had some black/rubber streaks on them. One of the boats we have has rubber marks but wasn't on the tire enough to cause a hole. The trailer tires did leave some rubber on the boats but we didn't notice any big change in the tires. You would think the rubber of the tire would break down faster than the plastic and we would have had blown tires but we didn't. I think the same tires are still on that trailer a year later.