Care & Repair of your NDK sea kayak


  • Remove hatch covers when transporting.
  • Unless the kayak is being carried in a customized rack, we advice fastening the kayak upside down on a padded roof rack.
  • The bow and stern should be tied to the front and rear of the vehicle.
  • Try and park the car in a shaded area. The surface temperature of dark coloured kayaks can increase as much as 20 degrees more than white surfaces.


Always remove hatch covers and store the boat upside down, out of direct sunlight and ideally under cover. If water does get inside the cockpit and hatches then sponge dry, as kayaks will absorb water from the inside. Do not store the kayak on damp ground as it could cause osmosis.


Polishing your kayak will fill in small scratches and make your kayak look newer. In reality though it is actually removing a small layer of the gel coat making it thinner so do it in moderation. Using a power polisher and a sheep skin buffer, or a rag and a lot of elbow grease work.

Finding leaks

If the leak isn’t obvious you need to increase the pressure in the boat to force air out of the leak. You can do this by taping a large plastic bag around the hatch rim of the suspect compartment. Then make a hole in the bag and use it as a bellows to increase the pressure in the compartment. Your boat may have a tiny hole drilled in the bulkhead to equalise pressure, you will then need to tape this up from the inside of the compartment you are testing.

Then, using a 50/50 washing up liquid-water solution and a paint brush, apply the solution to anywhere you think there might be a leak. When you see bubbles you have found the leak.

You can also fill the suspect compartment with water and see if you can spot where any drips are leaking from. This only works for some leaks where as the previous method works for most leaks.

How to fix a hole through the glass in the hull

From the inside:

  • Sand the area around the hole. Remove any dust and clean the surface using acetone.
  • Cut out 4 pieces of chopped strand mat that overlap the hole by about 2″ (50 mm) all the way round.
  • Wet them out using resin mixed with catalyst (this makes the resin go hard).
  • Place them over the hole layer by layer. Make sure the edges are pressed down well.
  • Leave to harden.
  • Sand down any rough edges to leave it smooth.

From the outside:

  • Mix gel coat with the colour pigment & catalyst.
  • Fill the hole making sure there are no air bubbles trapped in the gel coat.
  • Fill above the level of the surface.
  • Leave to harden.
  • Smooth down using wet & dry sand paper.

Gel coat repairs and star cracks

Never try to gel coat repair shallow scratches. A thin layer of gel coat isn’t structurally strong enough to prevent itself cracking off. Either deepen the scratch using a small blade or grinder, or leave it. Unless the scratch goes through to the glass matting it won’t harm the boat.

Thin hairline cracks – star cracks – present a bigger problem. These need to be repaired eventually. It’s ok to leave them until the end of the season but much longer than that and water will penetrate the glass fibre matting and cause it to delaminate. These need to be widened using a small blade or grinder and then repaired with gel coat.

Wipe the repair with styrene to re-activate the old gel coat. This provides a chemical bond rather than just a physical one. Apply masking tape around the area. Add the catalyst to the gel coat according to the manufactures advice and mix well. Brush the gel coat over the area, remove the masking tape and leave it to dry thoroughly. Sand the repair flush using a sanding block and working your way through wet and dry paper, from a course grit to a fine one. For best results polish the area. For a bomb proof job, glass a thin layer of matting on the inside of the hull covering the area of star cracks.

Colour match gel coat

The hardest part of a repair to the surface of a coloured fibre glass boat is matching the colour shade. Even “factory colours” don’t match exactly after a boat has been in the sun for a few years. The best way to match the colour of your boat is to use a colour match gel coat kit. (Internet search engine tip: Enter colour match gel coat kit + your area).

A colour-sample card from your local paint shop that matches your hull can provide help. Ask the shop assistant the ratio. They custom-mix the colour by adding tints to a white base, the same as in the kits. The formula may call for a half-dozen different tints, but the important ones are those specified in the largest quantities. You can use the tints in the kit to approximate the ratio.

Always colour gel coat before you add the catalyst. Keep track of the number of drops of each tint. When the colour looks close in the cup, touch a drop of the mix onto the hull. Make needed adjustments until you are satisfied with the match then write down the formula so you can duplicate it for the rest of the paste.

Fix a leak in Kari-Tek Skeg box

Some earlier Kari-Tek plastic skeg boxes have come partially loose and started to leak. This procedure is for fixing the leak and making the skeg box to hull joint stronger to prevent any future leaks.

Equipment: Denaturated alcohol, PVC glue, 164 g/m2 fiberglass rowing, 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.

  • Find the leak: Test back hatch with water, rotating the kayak on a sawhorse. If the skeg box leaks water in, it will normally also leak it out. You should see a crack in the area where it leaks, between the skeg box’s white plastic and the hull from outside of the kayak
  • Disassemble skeg internals
  • Grind the area on the outside around the skeg box with a narrow belt sander to get maximum adherin of new resin to the area. Sand also the area on the inside with 100 grit sand paper and a wedged soft grinding block
  • Pry open the defective area as far as it easily goes, using the small wooden wedges
  • Shine the flashlight to the opened crack and look inside to see if the water comes through a thin spot of the reinforcement GRB or if the GRP is fully delaminated from the skeg box side
  • Clean the gap with denaturated alcohol
  • Let dry overnight (kayak right side up), as there may be water in the structure
  • Make a tapered board that can be used to pry the sides of the skeg box tightly to the hull.
  • Apply PVC glue to the wedged out -gap. Try to get it as deep as possible e.g. with the tip of a feeler gauge. Then press the wedged board in and clean up the residue
  • Let dry for 24 hours
  • Cut pieces of rowing to go on the outside and inside for reinforcement of the area, 2 layers minimum
  • Remove the wooden wedge from the skeg box
  • Clean up the areas with acetone and rag
  • Soften the edges of the skeg box with PVC-glue
  • Make a 140 g batch of polyester resin and glass the 2 layers of rowing on the inside and preferably 3 layers on the outside
  • Let dry for 1-2 hours until properly gelled
  • Sand smooth, remove dust with vacuum and an acetone-dipped rag
  • Apply masking tape around the area
  • Make a 160 g batch of white (or other hull color) top coat
  • Paint over the fixed areas first with standard top coat, then thicken it to putty-consistency and do it again to fill any gaps
  • Remove masking tapes when still wet
  • Let dry 24 hours (due to PVC-glue)
  • Sand open the skeg box slit with a narrow belt sander
  • Reassemble skeg internals
  • Test for leaks

Repair a damaged Kari-Tek plastic skeg box

Equipment needed: Allen key set, hand router, acetone, adequate safety equipment, 40 grit sandpaper, wax, gel and hardener, resin and hardener, fibre glass matting, marker pen, masking tape, brushes.

  • Use the Allen key to undo the grub screw located in the skeg operating slider near the cockpit area (this will release the skeg wire from the skeg slider)
  • Turn the kayak over (upside down) and use the Allen key to undo the two Allen key bolts on the front and the back of the skeg cassette. Then pull the skeg cassette out and the wire should follow
  • Inspect the area of where the damage is and mark with a marker pen the length of area which has released
  • With the hand router, carefully router the damaged area alongside the plastic lip of the skeg box (try not to router any of the plastic lip away), also try not to plunge the router in too deep, only about 8mm deep. Use the markers previously drawn as a guide to the length needed to be routered away
  • Clean area up of any dust and grit, then using masking tape, tape area up to stop any splashes of resin or gel to get on to the kayak
  • Mix a little resin with hardener and wet out little bits of fibre glass matting, fill the hole which has been routered out with the wetted out matting
  • Use a brush to stuff it in, but just enough to make sure that there is no air
  • Leave to harden
  • Once hardened, sand down smooth with the 40 grit sand paper, then mix the gel with hardener (also put a little wax in so it’s not sticky afterwards). Brush the gel on top of the repaired area, clean away any drips etc with a cloth dipped in acetone (use gloves etc)
  • When complete follow steps 1 and 2 in reverse order to re-connect the skeg cassette.

Renewing the Wire in a Kayak with a Plastic Skeg Box

  • Using an ALLEN KEY, undo the Grub Screw (Anticlockwise) in the Skeg Slider at the side of the boat. Only undo it enough so that it no longer grips the old wire, not all the way out.
  • Undo the two ALLEN Bolts, which hold the Skeg Blade assembly in place and pull down the whole Skeg Blade assembly, then undo the screw, which holds the old wire in place. Pull out the old wire.
  • Locate the fitting on top of the Skeg Box through the Rear Hatch. Using a 13mm Spanner, undo the TOP nut only. Do not undo the lower nut. When it is loose, pull the Nylon Tube out of the fitting. There should be a brass ring stuck to the tube. Do not try to remove this. (This ring forms the waterproof seal).
  • Slide in the new wire from the Skeg Slider end until about 6” project from end of the loose tube at the Skeg Box end. (The softer wire tends to fray, so be patient with it !!!!)
  • Hold the end of the new wire at the Skeg Box end & feed it down the fitting on top of the Skeg Box until the Brass ring touches the top of the fitting. Place the TOP nut back on the fitting & tighten it back on using a 13mm spanner. (Do not tighten it up too much !!!). Push the end of the new wire into the hole in the Blade that you pulled the old wire out of, and tighten up the screw, which holds the wire in place.
  • From the Skeg Slider end, pull the wire until the whole Skeg Assembly is back into the box. Replace the two Allen bolts to hold it in position.
  • From the Skeg Slider end, pull the new wire through until the blade is back up in the box. Cut the new wire to length, so that the end just touches the front of the inside of the Skeg Slider box. With the blade fully up in the box, slide the Skeg Slider forward, and retighten the grub screw. The skeg should now work !!!!!