Exothermic Welding

Exothermic Welding

The Furseweld Exothermic Welding process is a simple, self-contained method of forming high quality electrical connections. The compact process requires no external power or heat source, making it completely portable. Connections are made inside a semi-permanent graphite mold using the high temperature reaction of powdered copper oxide and aluminum.

Exothermic Welding Equipment and Accessories

Weld Powders

Furseweld weld powders are contained in plastic cartridges, and are packed in plastic boxes of 10 or 20, depending on their size. Different joints require different powder sizes, and the size relates to the powder’s nominal weight in grams. The weld powder packaging also contains retaining discs and starting powder. The retaining discs are contained in a separate bag within the box. The starting powder is compacted into the bottom of the cartridge, underneath the weld powder, and is released by tapping the cartridge base firmly. Furseweld weld powders are suitable for making connections from copper to copper and from copper to steel.

Molds

Furseweld graphite molds are dedicated to producing one type of connection. With care,

they should be capable of producing up to 75 connections each. Mold size and complexity

varies, and is denoted by a price key, from one upwards. Each mold carries a tag which gives the mold part number, the weld powder size for use with the mold and the conductor sizes for which it is intended.

Handle Clamps

Handle clamps provide a means of both handling the mold, and also of clamping the mold halves together (or of clamping the mold to the surface to which a connection is to be made).

Standard Tools

A flint gun is required to start the reaction. 

Cleaning tools for conductors, surfaces and molds include:

Cable Brush - for cleaning cables and other circular conductors such as rods.

Mold Scraper - for removing slag from the mold crucible, after firing. 

Mold Brush - for final mold cleaning.

File Card Brush - for cleaning conductors and surfaces.

This is how it works:

The Mold (1) features a Crucible (2), a Tap Hole (3) and a Weld Cavity (4). The Conductors (5) and (6) to be joined, are located in the Weld Cavity as shown, and the Mold is closed. A steel Retaining Disc (7) is located in the bottom of the crucible, to retain the Weld Powder (8) and Starting Powder (9) which are poured in on top. Ignited with a spark gun, the starting powder sets off an exothermic reaction in the weld powder, reducing it to molten copper alloy. 

This instantaneously melts the retaining disc, and flows down the tap hole, to the weld cavity, where it partially melts the conductors, before cooling to leave a fusion weld of great mechanical and electrical integrity.