JB Weld is a trademark name for a two part compound similar to epoxy that can be used for mending parts. It comes in two tubes and is mixed in equal parts. Once mixed, it is applied to the part to be mended as a permanent adhesive, then allowed a set amount of time for setting and curing. Though it is strong, the product is in no way a substitute for welding as the name may imply. It tends to be the subject of ridicule (much like duct tape) as it tends often to be substituted for a proper repair.
J-B Weld Website