How to Repair a Leak in a Grumman Canoe

The ubiquitous Grumman aluminum canoe shows up everywhere canoers gather. They are sturdy, lightweight and last nearly forever. Over time and with the kind of abuse canoes get, however, even the sturdy Grumman can develop a leak. There are several ways to solve the problem, temporarily or permanently.

Things You'll Need

  • Propane torch
  • Durafix aluminum repair rods
  • Stainless steel wire brush
  • Safety goggles
  • Leather gloves
  • Mallet
  • Scissors
  • Pocket knife
  • Fiberglass patching cloth
  • Fiberglass resin
  • Plastic spreader tool
  • Disposable cup or bowl
  • Hand sander and sandpaper
  • 2-pound hammer
  • Ball-peen hammer
  • Nail punch
  • Truss-headed stainless steel Philips bolts, 3/8 inches long with lock washers and nuts
  • Marine sealant
  • Phillips screwdriver
  • Small socket wrench set
  • Power grinder and grinding wheels
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Instructions

  1. Torch Repair

    • 1

      Clean the area around the leak. Remove paint if the surface is painted. Don goggles and gloves.

    • 2

      Brush the area to be welded with a stainless steel wire brush until clean and shiny.

    • 3

      Light the propane torch and heat the area to be welded. Heat evenly, passing the torch back and forth slowly across the area.

    • 4

      Rub the Durafix rod rapidly back and forth against the hot metal as you continue to work the torch back and forth to keep the surface hot.

    • 5

      Watch for the rod to begin to melt. As it does, spread a thin layer of molten metal across the area where the leak is until you have a smooth, even coating. Allow the area to cool and then test for leaks. Repeat until you get the leak sealed.

    Resin Repair

    • 6

      Hammer out any dents around the leak with the mallet. Clean and dry the area.

    • 7

      Cut out a square section of fiberglass patching cloth a half inch or more larger than the section to be repaired. Sand the hull around the area to be patched and just a bit larger than the patch.

    • 8

      Mix up the fiberglass resin in the disposable bowl according to the manufacturer's instructions. Paint the cleaned and sanded area with the resin.

    • 9

      Lay the fiberglass repair cloth on top of the resin and smooth it with the spreader. Work the patch until all the trapped air bubbles inside the weave are gone and the patch disappears. Apply a light coat of resin over the top of the patch.

    • 10

      Allow the resin to dry and cure overnight. Sand the area to help it blend in. Start with coarse sandpaper and gradually use finer grade sandpaper until the area is smooth. Repaint the canoe if it was painted already. You can also leave the clear patch as it is.

    Rivet Repair

    • 11

      Hold the 2-pound hammer head against the rivet on the inside of the canoe.

    • 12

      Place a nail punch against the head of the rivet on the outside of the canoe. You'll need a partner to do this part.

    • 13

      Press the 2-pound hammer against the end of the rivet.

    • 14

      Tap the head of the rivet from the outside to re-expand the rivet and tighten the connection.

    • 15

      Tighten the rivets four or five rivet holes on either side of the place where the rivet is leaking. This might be all you need to do to stop the leak.

    Rivet Replacement

    • 16

      Drill out the rivet hole to exactly fit the truss-headed Phillips bolts.

    • 17

      Dip the bolt in marine sealant and insert it into the freshly drilled hole from the outside of the hull while it's wet.

    • 18

      Screw on the lock washer and bolts from the inside.

    • 19

      Grind off the excess bolt with the grinder and apply another light coat of sealant to the nut. Repeat with any other leaking rivets.