Leakproof moulds for thermite welding metal profiles - sealed by strip of resin becoming refractory at high temp.

摘要

In an aluminothermic welding operation on two metal objects, the leakproof jointing of the various parts of the moulded is ensured. The surfaces of the mould coming into contact with each other have a bead of resin applied, of a type which is plastic in the cold state, and decomposes into a refractory material at >250 degrees C. The bead of resin may be applied to grooves machined in the mould surfaces, and is a silicon elastomer, extruded from a gun. System is much simpler than applying a mixture of silica sand, clay and water, etc., since the moulds only need to be pressed together.