Repairing a leak in a Kari-Tek skeg box

Some earlier Kari-Tek plastic skeg boxes have come partially loose from there glass composite surrounding and started to leak.

These instructions are for fixing the leak and making the skeg box to hull joint stronger to prevent any future problems. 

What you will need:

• Denatured alcohol
• Gloves 
• Mask
• Goggles
• PVC glue
• 164 g/m2 fibreglass woven roving matting
• polyester resin and hardener
• masking tape
• top coat, hardener and thickener (glass balls).
• Sawhorse
• hose
• water
• Allen wrench set
• slotted screwdriver
• narrow belt sander
• sand paper 100 grit
• wedged sanding block (soft)
• small wooden wedges
• flashlight
• ShopVac.

Instructions

• 1. Identify the leak: You have two options.
     1. Test the back hatch by applying water while rotating the kayak on a sawhorse. If water leaks into the skeg box, it should also leak out. Look for a crack between the skeg box’s white plastic and the hull from the outside of the kayak.
     2. Alternatively, increase air pressure in the stern hatch by taping a plastic bag opening around it. Poke a hole in the bag and use it as a bellows to increase air pressure. Apply a soapy solution to the suspected leak area and watch for bubbles forming as air escapes.
  2. Disassemble the skeg components.
  3. Use a narrow belt sander to grind the area around the skeg box externally for optimal adhesion of the new resin.
  4. Internally, sand with 100 grit sandpaper using a wedged soft sanding block.
  5. Gently pry open the defective area with small wooden wedges.
  6. Use a flashlight to inspect the crack. Check if water passes through a thin spot of the reinforcement GRP or if the GRP has fully delaminated from the skeg box side.
  7. Clean the gap with denatured alcohol.
  8. Allow drying overnight (kayak right side up) as water may remain in the structure.
  9. Create a tapered board to pry the skeg box sides tightly to the hull.
  10. Apply PVC glue into the wedged-out gap. Try to get it as deep as possible.
  11. Press the wedged board in and clean any residue.
  12. Let it dry for 24 hours.
  13. Cut pieces of woven roving matting to reinforce the area with a minimum of two layers externally and internally.
  14. Remove the wooden wedge from the skeg box.
  15. Clean the areas using acetone and a rag.
  16. Soften the skeg box edges with PVC glue.
  17. Prepare a 140 g batch of polyester resin and apply the two layers of woven roving matting internally, and preferably three layers externally.
  18. Let dry for 1-2 hours until properly gelled.
  19. Sand smooth; remove dust using a vacuum and an acetone-dipped rag.
  20. Apply masking tape around the area.
  21. Prepare a 160 g batch of white (or other hull colour) top coat.
  22. Paint the repaired areas with standard top coat, then thicken to a putty-consistency and reapply to fill any gaps.
  23. Remove masking tape while still wet.
  24. Allow drying for 24 hours (due to PVC glue).
  25. Sand open the skeg box slit using a narrow belt sander.
  26. Reassemble the skeg components.
  27. Test for leaks.