Fixing a hole in the deck or bottom of the Varuna Surfboard

Before repairing the damaged area make sure you’ve left your Varuna out of the water long enough for it to dry fully and all water to have been drained from the compartment.
Now, inspect your damaged area and remove all wax that may be near the ding. In this case we’ve used a fresh board so no wax was harmed in the making of this clip.
Using a holesaw mark the area around your ding as a guide where you will be removing the dinged wood..
Cut through the area with your hole saw. You can see here that we are right up against the horizontal rib and where the watertight gore-tex has been applied to the rib holes.
With a pencil, mark a circle 2cm beyond the hole you’ve cut. This is what the balsa repair patch will sit on once you’ve completed the next steps.
Using a file, sand from the 2cm overlap back to the original hole, creating a reverse lip. Now hand sand an extra 2cm from where your lip starts so that when you repair the board you can bond to this area firmly. Sand lightly, making sure not to take all the glass off, except for the immediate damaged area.
Take the balsa repair patch supplied by Varuna and mark a circle the same size as the hole, including the lip area. Cut this out and hand sand the edges so that it will sit neatly in the hole you’ve created.
Fit the piece into the hole, making any small adjustments needed so that it fits flush with the board. Once you’re happy with how the balsa repair patch fits, mark the top, bottom, left and right sides so you can fit this easily in the next steps.
Measure the depth of your hole using a ruler. Mark the depth on a piece of plastic sheet. You can find this at your local newsagent. Cut a rectangle using a stanley knife from your measurements. Line this up with your damaged hole and bend the plastic to create a tube that is 3cm wider than your hole. Once inserted into the hole this will create a strong reinforcement.
Tape the edges together to make the plastic tube. Fold it in half as seen here and insert into the hole, letting it spring back to tube shape once inside the board. Adjust the positioning so all sides of the tube are covered by the deck.
We use boatcraft pacific’s 2 part pouring expanding foam to fill the tube, reinforce the repair and create a base for the balsa repair patch.
Mix a ratio of 1 parts ISO Part A with 2 parts Polyol Part B together in a cup. For this repair the measurements were 5ml ISO Part A and 10ml Polyol Part B. We used 2 separate plastic syringes for this so the two parts didn’t come into contact in the cans.
Sit back and watch the expanding foam rise from the base of the hole, up and through the lipped opening. This should take 10 minutes and be fully set within 30 minutes.
Once set, sand down the excess expanding foam.
Use a small, hard sanding disk to take the expanding foam down to the bottom of the reverse lip. This is where your balsa repair patch will sit neatly.
Sand around the damaged area using 80 grit with a hard pad on the sander, making sure to go 10cm over into undamaged fibreglass so that when you add the fibreglass cloth and resin it will bond to this area firmly. Sand lightly, making sure not to take all the glass off.
Use tape to mark the area the resin will be added so that it doesn’t spread further across the board.
Mix your resin with 2 parts resin and 1 part hardener with a pinch of cab-o-sil.
Pour the resin into the sunken area that you’ve created and spread it around so that all repair surfaces and edges are covered.
Place the balsa repair patch firmly into the sunken area. Weight this down, we used a roll of duct tape and dumbbell weight. Wait 24 hours for this to set.
Starting with a hard pad, sand back the edges of the resin that overflowed. Switch to a soft pad to bring the hard resin down to deck level. Finish with a hand sand on a hard pad and rough the edges of the damaged area again for your 6oz fibreglass cloth layers.
Cut a circle of fibreglass cloth to fit over the repair as seen here. Then another rectangular piece of cloth that will cover that for extra strength.
Lay your circular piece of cloth down and brush the epoxy resin mix onto the area. Repeat this process with the rectangular piece of cloth. Swipe the area with a hard edged piece of plastic to remove any air bubbles that may be there. Then brush more resin over the top so that all areas are covered.
When the resin is tacky, almost set, trim the cloth back to make the next step easier to sand back.
Leave for 24 hours to set before removing the tape.
Sand back the area with 120 grit and a hard pad. At this stage you don’t want to sand back too much, just enough to smooth the area.
Brush the filler coat on. Use 150 grit to sand the filler coat back using a soft sanding pad to maintain the curve of the deck.
Spray a clear coat over this and the final step is a wet sandpaper with 400-600 grit to create the final smooth touch.