Repairing a Kevlar Canoe or Kayak

GreenG's picture

Repairing a Kevlar canoe or Kevlar kayak is actually easier to repair than repairing a fiberglass or carbon-fiber canoe or kayak, especially if it is a major impact against a rock.  If you have a major impact in a fiberglass or carbon-fiber canoe you can have a "blowout" (hole punched in your boat).  A Kevlar boat will not blowout because Kevlar doesn't break, just the fiberglass layer over the Kevlar breaks (you can cut Kevlar with a sharp object like a knife, but not break it by bending it).  What you end up after a major impact that compromises the structure of the boat hull is a floppy leaking Kevlar spot.


Repair:  Peel away the broken fiberglass and resin bits at the area of the break.  You need to create some sort of temporary supporting structure on the inside of the hull of the canoes (for example a large block of Styrofoam or Ethafoam) carved to fit the curve of the hull.  Put a plastic sheet between the Styrofoam or Ethafoam and the hull to prevent the epoxy used in the repair form from melting the Styrofoam or seeping into the crevices of the Ethafoam.  Make sure the carved Styrofoam or Ethafoam is pressed firmly against the inside of the hull in the area being repaired.


On the exterior hull, cut out a section of fiberglass to cover the area (just overlapping the edges of the hole that hasn't been broken).  Mix up the two parts of epoxy resin (caution - only use epoxy that takes longer than 5 minutes to set up).  Make sure the epoxy is new, use equal part of the two-part mix, and stir thoroughly (approximately 50 stirs with a butter knife).  Lay a sheet of tin-foil on a breadboard.  Lay the cut out section of fiberglass on the tin-foil.  Spread the mixed epoxy resin on the fiberglass section with a butter knife.  Work-in until the fiberglass appears clear.  If you want a thicker patch, use two layers of fiberglass - in that case put the second fiberglass sheet on top of the fiberglass you put the resin on and smooth the second layer of fiberglass on top of the first layer.  Add more resin until the two sections together are clear.


With the canoe upside down so that the patch area if possible is horizontal, smooth on mixed epoxy resin until the Kevlar appears clear (e.g. no bumps or air bubbles).  Then peel the epoxy wetted the fiberglass section from the tin-foil and place it onto of the Kevlar wetted by the resin. Smooth the fiberglass section onto the Kevlar.  Using 60-minute epoxy, you  need to complete this process within thirty minutes (faster if it hot outside). 60-minute epoxy starts to stiffen after thirty minutes.  Let it cure over night.  Do not let it get wet from rain.  Note: Do not mix the epoxy if it is very humid outside which is often the case if working in the evening).  Moisture in the air will prevent the epoxy from completely setting up - you will end up with a sticky mess.  Also old epoxy (i.e. over a year old) will never completely setup.  If making repair inside, make sure you have adequate ventilation.  I would recommend wearing a half mask with a charcoal filter (which you can buy at Lowe's or HomeDepot) when you mix and work with epoxy resin.


Some people like to place a sheet of plastic sandwich cling wrap on the patch before the epoxy has cured to create a smooth finish will reduce the amount of sanding you have to do after the epoxy has cured.  Note first test the plastic wrap by putting a sample of mixed epoxy on it.  Some plastic wraps, such as Saran wrap, partially melts from the epoxy.  If placing plastic wrap on the epoxy patch make sure that all the air bubbles are smoothed out.


The next day after the patch has cured, sand smooth with sandpaper.  Start with course sandpaper, then going to medium, then to fine sandpaper.  Finish by wet sanding for a smooth finish.  For a really smooth finish, finish off with a buffing compound.


When you are finished with the patch, take your repaired canoe or kayak by taking it over to Mirror Lake (longest man-made lake in New Jersey) this Saturday, July 28, in Brown Mills, New Jersey and test it out in the 2012 Mirror Lake Recreational Canoe and Kayak Race at the Pemberton Township "Water Carnival", see


  Or you can test your repaired canoe or kayak at the" Festival of Lights" Recreational Canoe and Kayak Race on Saturday, August 4 on the tidal Delaware River in Burlington, New Jersey, see



  Glen Green