Coated Welding Electrode: Iron Wire Dipped in Chalk and Water Glass (Kjellberg, 1907)

In 1907 Oscar Kjellberg patented a welding electrode made by dipping bare iron wire in a thick mixture of carbonates and silicates. In the arc the coating gives off a fume that keeps air away from the molten metal while it cools. Here the carbonate is chalk and the silicate is water glass. Cut the wire to length, dip it in the paste, and dry the rods well before use. The picture: our diagram of the wire, the dip and the coated rod.