How to Repair Damage to Plastic Kayaks and Canoes

Lear to repair scratches, holes, gouges and cracks

Kayaks in Norway at the Geiranger Fjord against a mountainous backdrop

Hans-Peter Merten/robertharding/Getty Images

The material that many plastic canoes and kayaks are made of is called high-density polyethylene (HDPE), and it is an extremely difficult material to repair. The same chemical properties that make your boat extremely flexible and durable also prevent other materials from bonding to it.

HDPE is resistant to repairs utilizing typical adhesives and sealants in most applications. However, this doesn’t mean that scratches, gouges, holes, and cracks in plastic kayaks must go unfixed. Explore guidelines for how to repair each type damage you may encounter over the lifetime of your boat.

Scratches and Gouges in Kayak Hulls

Scratches and gouges are the most common damage to plastic kayaks. Kayaks are dragged along shorelines and paddled over shallow rocks. They also get banged into numerous things as we carry them from storage to the top of a car.

Scratches are part of the sport and, for the most part, they are nothing to be concerned about. Some of these scratches accompany peeling or fraying of the plastic itself. These plastic shavings are no issue either. If there are thick scratches that peel back the plastic, you can simply take a razor blade and trim those areas.

At times, the gouge may be deeper than usual and will be large enough to concern you. In these cases, plastic can be drip melted into the crack to fill it in.

  • The best plastic to use is plastic from the kayak itself from any cutouts you may have saved or other repairs you made in the past.
  • Otherwise, you can purchase HDPE weld rods from many paddling shops. You can even use containers like milk cartons which are made from HDPE.
  • Simply take a lighter to the plastic and as it melts, it will drip. Allow these drips to fill in the scratch. Use a spoon or screwdriver to smear it into the groove. Sand or trim off any excess and make the repair smooth.

Holes in Kayak Decks

While it is rare for the top of a kayak to develop a crack, holes are quite common because of all the things that are screwed into them. When screws are lost or accessories are removed, it leaves a hole and when water splashes up, it can get inside the kayak. Obviously, you wouldn’t scrap a kayak under these circumstances.

  • Something as simple as duct tape will keep water out. It will just need to be replaced on a regular basis, but it's a decent temporary fix.​
  • A waterproof UV resistant silicone can also be used in this situation. These can be found at hardware stores and are typically labeled for 'marine' use. Use duct tape on the underside of the hole to act as a temporary foundation, then fill in the hole with the silicone from the top.

Cracks in HDPE Kayaks

Cracks are the most serious damage that can occur to a kayak and location is everything. Many cracks on the top side of a kayak can be handled much in the same way as a hole, with either duct tape or silicone. While neither solution will fix the crack, both will prevent water from entering the kayak.

It's a completely different story if the crack is on the underside of the kayak. This is the side that supports your weight, hits rocks, and keeps the boat from sinking. Unfortunately, this is also where cracks occur most often and they require serious attention. The kayak should not be paddled until they are permanently checked out and dealt with. 

The most serious location for a crack is under the seat and forward to the foot pegs. This is the area where the paddler’s weight and force is most often exerted in nonuniform ways. Cracks up toward the bow or back toward the stern are less serious. These areas don’t have near the flexing that the seat area has, though they are still a concern.

Regardless of where the crack is, the ends of it should be drilled to prevent further propagation and the cracks will need to be plastic-welded. If you are going to have a professional do this, leave the drilling to them.

Turn to the Pros?

Consult a kayaking shop or rental business to direct you on the next steps. They will assess the severity of the crack with regard to its size and location. When looking at the size, they will check for not only the length of the crack but how wide open it is. Obviously, a gaping opening is more serious than a hairline crack.

If you are going to attempt the repair on your own:

  • Using a small drill bit, put a small hole at each end of the crack so it doesn’t spread.
  • Plastic weld the crack to complete the repair. You will need a plastic welding kit with HDPE welding rods and it works in a similar fashion to a glue gun.
  • Plastic can also be repaired with a lighter or torch and plastic remnants.

When trying to repair a serious crack on your own, you are risking further damage to your kayak. It's also possible that whatever you do will not be repairable by a professional. Think carefully before starting and proceed at your own risk.