The Aqua Marine Repair Epoxy Putty Stick is a good way to fix a crack in your kayak in a difficult to reach place such as inside the hatches along a narrow curved surface.
The way it works is very simple. The epoxy hardener and resin are wrapped on top of each other. You need to cut a 1 inch slice like a sausage. Then do a mixing roll in your hand until it is homogeneous. It will get hot. You then spread the mixed putty on top of the crack, and let it cure for about an hour.
The video below from East Marine Asia shows the procedure.
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