The exothermic welding is a self-sufficient process to achieve high quality electrical connections between copper, copper alloys or steel conductors. The process implies the use of a graphite mold allowing the molten metal present inside to come in contact with the conductors present and to weld them in a definitive way.
The sealing compound is used in cases where the conductors to be welded do not have a smooth surface, for example, when welding a cable to a rebar, or a cable to a steel surface. The sealant is applied in contact with the element to be welded and the outer wall of the mold to seal the existing gap and allow the molten metal not to flow out of the weld cavity. A complete box of sealant allows for approximately one hundred welds.