Abstract: An exothermic welding jig, molds for the jig, and a method of forming and manipulating the mold parts is disclosed. Upper and lower mold parts are included with a crucible fitted on and clamped to the upper mold part. The upper mold part and crucible may be moved as a unit to open and close the mold and also inverted when open for cleaning and inspection. The crucible can quickly be removed or snapped in place for mold or crucible change out. The jig will fit in cramped quarters and has a handle which may be used as a cane or supporting device. A toggle opens and closes the mold set and will hold the molds at any position where released. A mold system with diagonal sleeving makes it easier to form X-connections and other connections in tight or restrictive locations. The method includes the attachment and manipulative steps.