Epoxy; a great chemical that works in boat building and repair, and much more, including fiber boat repair. Its use is not limited to boats and can be used in general woodworking, even in domestic repairs. Epoxy Hardener technically consists of a mixture of resin and hardener in different proportions. When you mix it in an appropriate ratio, an exothermic reaction that gives off heat starts and the epoxy gradually hardens. The gel (or jelly) stage first passes through a given stage, then this jelly continues to harden slowly and becomes stiff. Frozen epoxy is an extremely strong adhesive with excellent waterproofing properties. You can work on it until the epoxy comes to the jelly stage.