How to repair a crack in an ABS kayak

Anyone have experience repairing a crack in ABS? I need to repair a crack in a Current Design TCS Kestrel kayak. Apparently, TCS is just CD’s name for ABS.

From a Paddling post - TCS stands for Thermo Composite System. It is a CD trademarked ABS plastic similar to thermoformed plastics used by Seaward, Delta, Hurricane Aquasports, Eddyline, etc.

Clear or white products recommended to chemically fill and weld a crack, not a gouge, in ABS include Gorilla 2-Part Epoxy, Clear, J-B Weld, 50101 MinuteWeld Instant-Setting Epoxy Syringe - Dries Clear, Loctite 1919324 Marine Epoxy, White, Weld-On 4 Acrylic Adhesive, and SCIGRIP (a Weld-On product) 10315 Acrylic Plastic Cement – Clear. I am leaning towards J-B Weld, 50101 MinuteWeld Instant-Setting Epoxy Syringe - Dries Clear. The crack will need a backer inside the kayak with limited access. Using a product that works instantly will keep an ABS backer in place until I can put a small weight on it.

Superglue is OK for applications that won’t be wet. A Permabond chart lists Superglue resistance to water as poor.

West System’s G Flex epoxy will give you the strongest bond to ABS plastic and is easy to use. I have used it to repair and bond cloth to the ABS of many Royalex canoes.

if you can access the hull interior you can also use G Flex to wet out and bond a fabric patch.

Thanks. Do you mean a fiberglass fabric patch? If not, what material?

I would use either fiberglass or aramid (such as Kevlar). Aramid fabrics provide greater tensile strength per weight but are more expensive than fiberglass. For a relatively small patch the weight difference is not of much significance. S fiberglass is about 20-30% stronger than the usual E fiberglass but at least twice as expensive and less readily available

I think a patch of garden variety E fiberglass would suit fine. I would use a plain weave fabric of 6 ounce/square yard weight. Cut the patch so that the lines of the weft and weave are on a bias, in other words, you want them to cross over your linear crack at a 45 degree angle.

I still have a bit of abs weld wire, cut into pellets, that I’d mix with acetone to make a slurry. Gorilla glue used as a barrier between the slurry and any foamlike substrate. The G-flex is a much easier fix, and at least as good, though the abs is good for shallow dents/gouges/cracks…if you try it, work fast.

Here’s a step-by-step description by Ethan Ebersold, sales rep for Eddyline and other kayak brands. It works. Following his instructions, I repaired a thermoform seat which had been badly cracked.


Although I have not used it, I do know some who have repaired ABS (Royalex) boats with Devcon Plastic Welder and even used it to wet out and bond cloth with good results. But be aware that is has a quite short working life, on the order of a few minutes, so if you use it you better have everything you need laid out and ready to go, and know exactly what you are going to do.

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I’m not sure about Current Designs, but I know Eddyline and Delta sell repair kits. You could look at those.

Thanks for all the well informed suggestions. Most suggestions, here and elsewhere, suggest using Devcon Plastic Welder so that is what I went with. One detail that would help is to specify the Two-Part METHACRYLATE Adhesive version of Devcon plastic welder. Some Devcon products listed as plastic welder are just superglue, something that does not work well in water.

Question - What is the advantage of orienting the fiberglass backer weave on a 45 degree bias? I am thinking it may make a stronger bond that resists breaking when stressed or makes a flexible bond that gives with stress but doesn’t break. Of course there could be a third option.

If you orient your patch on the bias you will have twice as many fibers crossing the crack than if you orient the axis of the fibers parallel to the crack.

Once again, if you are going to apply a patch, be prepared to work quickly. You need to have everything ready to go and the area all masked out.