Forge welding is the traditional blacksmith's method of joining two pieces of iron or steel by heating them in the forge until they are almost molten and then hammering them together so that they fuse into a single piece. It is sometimes called fire welding, and it was the only practical way of joining iron before modern electric and gas welding were developed.
To make a sound weld, the smith shapes the ends to be joined, brings them to white heat, often dusting them with sand or borax as a flux to clean away scale, and then strikes them quickly on the anvil. The technique was used for everything from chain links and tools to wrought-iron gates, railings, firedogs and grates, and it lies behind the patterned blades of pattern-welded steel. On antique ironwork, forge welds are a sign of genuine hand work, often visible as slightly swollen joints or faint seams, in contrast to the bead of a modern arc weld. Conservators and specialist smiths still use forge welding when repairing historic wrought iron, because it is sympathetic to the material and preserves the character of the original piece.
