Patching Polyethylene

I bought a polyethylene kayak last year. This year when I took to out to the water for the first time, I now have a crack in it. I was wondering if anyone knew how to patch it. Thanks.

one year old boat with cracks?

take it back to where you bought it.

plastic can be welded. If not gutter repair tape works. Home Depot or Lowes.


Only a year old should be under warrante
I you bought a used boat I’d drill a hole at each end of the crack tonight to keep it from spreading. Then I’d patch it with duct tape or gorilla tape until you get you patch kit from the place that sells that patch that you mold with a heat gun.

I’ll try to find the link.

He is what you need

not sure about material
but word was the old coleman canoes could be patched by melting a plastic milk jug into the crack. I think those are polyethelene as well. We’d light the jug and drip the melted plastic into the crack.

linear vs crosslink poly
I believe that Coleman used linear polyethylene which can be plastic welded and recycled.

Crosslink polyethylene, which many boats are made of, has higher impact resistance, but is very difficult to weld. I doubt the melted milk jug method would work on crosslink poly, but I haven’t tried.

Patching Polyethylene
Would the water continue to leak into my kayak after i use the patch kit? I heard something about a plastic welder.

also the hot knives
method which I’ve only heard of, being a royalex guy myself. Heating a knife up, then sticking it into crack, melting poly and pulling the knife out.

Welding poly
Try to find out if your boat is made of linear polyethylene or crosslink polyethylene. The manufacturer should be able to tell you. Also, check with them regarding a hull waranty. Occasionally, a maker will replace a hull, or at least give you a pro-rating on it, if it failed in such a way as to suggest it was defective. Rotomolded boats not infrequently come out with voids or thin spots that weaken them.

Earlier whitewater boats such as the Perception Dancer were made out of high density linear polyethylene and could be plastic welded. There was a guy I knew in the South who would do these repairs. Later boats were usually made of cross link poly. People I know who had these hulls welded had the welds fail in short order.

Look into West System’s G flex epoxy. I have not used G flex, but West System claims it bonds to poly. I know a number of people who have used it on ABS, which traditionally has been difficult to achieve a lasting bond with, and have had good results.

you got that backwards. Originally Dancers were made of x-linked THEN we switched to linear. x-linked is hard to weld.

hardly anyone uses x-link anymore. not eco friendly at all. no recycle, toxic fumes, etc.

linear can we welded with a welder, soldering iron, hot knife and milk jug, dripping melted plastic or patched. pro welded with a wire feed welder is best.


poly repair
I seem to remember a time when most of the Perception boats were made of linear poly, then Dagger started making boats out of x-linked poly or offered it as an option, and then Perception followed suit, but my memory plays tricks on me these days.

I had some friends who had their linear poly boats professionally welded, I presume using the wire-feed welding method, and the results were cosmetically good and the repairs durable.

Do you have any experience with G flex for repairing polyethylene boats? A local nature group I volunteer for has several Old Town Discoveries with severe stem abrasion in need of repair and I would like to know if I can get S glass to bond to these with G flex.

they started
with cross linked and then found linear to be easier to work with and more eco friendly. there was a time when the x-linked was the heavy duty option.

g-flex experiments have had mixed reviews and the jury’s not in. :wink:


go to you tube and search plastic welding


Patch vs welding
I like the patch better. Welding has not gone well for me inspite of having a good plastic welder.

I have just started using G-flex.

– Last Updated: May-06-09 11:18 AM EST –

Having already applied a successful S-glass patch to ABS scraped clean of vinyl, with West 105/205 as the resin, I can report that 105/205 sticks brilliantly to ABS. My concern about G-flex, however, is that is is thicker than 105/205 and may not wet out S-glass readily. Maybe if you choose a relatively open weave, not the tight weave I'm using.

As for those OT Discovery stems, because they do not undergo radical flexing under most circumstances, I think G-flex may stick well, using the torch-the-surface prep recommended.

However, for the bottom of a poly kayak, which may have to bend more sharply under impact, I'm not sure that G-flex will stick. It >might< if one uses a flexible cloth like Kevlar. But G-flex, while flexible, is still stiffer than poly, and when a patch is bent sharply, the shear forces may pop it off. The patch must be kept thin, and the transition zones controlled by using concentric cloth layers, largest first.

I have a thin plug of unused mixed G-flex that was left in the mixing vessel. It was usably hard in 24 hours, but still hardened further over at least two weeks. I can still drive a thumbnail into the surface, but it leaves no visible dent. The plug is maybe 1/8" thick, and can still be bent, though with difficulty.

Was your SE welder named Cumnock? Now on BT as ditchbitch.

Sea Kayak Magazine
Just read an article about the patch I mentioned above. It compared several different types of repairs and the patch won out.

Maybe I should be selling this patch?