How to Fix a Leak in a Boat Tube

Instructions

Remove the air bladder from the nylon cover and set the cover aside.
Mix a solution of dish soap and water in a bucket or other suitable container. Use enough soap in the water so it will create bubbles.
Dip the sponge in the soap solution and spread it over the bladder to find the leak. When you spot air bubbles coming up through the soap solution, you’ve found the leak. Lay the bladder on a flat surface with the leak facing you.
Draw a circle around the leak with a marking pen. Towel off the soap solution and let the area with the leak air dry until it is completely dry.
Lightly sand the area around the leak with the sandpaper. Don’t overdo it — you want it just slightly roughed up.
Cut a piece from the patch material from the repair kit to fit over the leak. You’ll want a bit of extra patch for the glue. Cut the patch into a round or oval shape.
Apply a thin layer of glue from the tube in the repair kit to both the patch and the area around the leak or cut. Wait a minute or so before putting on the patch.
Press the patch down onto the leak and press hard. Smooth out any air bubbles with your fingers. Allow the patch to dry for 24 hours before adding air to the tube, installing it back in its nylon cover and using it.

Here are some other videos that might help you learn How to Fix a Leak in a Boat Tube.