Epoxy is one of the strongest adhesives you can use for a number of projects, from simple crafts on up to repairing or sealing wood on a boat. Many types of epoxy require mixing together two substances to create a chemical reaction, forming the epoxy. An epoxy putty works a bit like a modeling compound or dough. Some have two different putty sticks, each a different color, that you knead together to give the adhesive its hardening, bonding properties. Others have both parts of the putty in the same stick, but you must still knead them together to cause the reaction. An epoxy resin is a two-part liquid set including the resin and the curing agent. Mixing them together in equal portions, then stirring, causes the reaction that starts the epoxy-curing process. Pour a clear epoxy over a tabletop covered in bottlecaps, for instance, to create a rock-hard resin tabletop with your collection set inside. No matter which type of epoxy product you prefer working with, reliable sellers on eBay offer a multitude of options and brands.