Why was Woods Metal developed?
Wood’s metal is useful as a low-melting solder, low-temperature casting metal, high temperature coupling fluid in heat baths, and as a fire-melted valve element in fire sprinkler systems in buildings. Medical gas cylinders in the United Kingdom have a Wood’s metal seal which melts in fire, allowing the gas to escape and reducing the risk of gas explosion. A common use is as a filler when bending thin-walled metal tubes. For this use the tubing is filled with molten Wood’s metal. After the filler solidifies the tubing is bent, and the filler prevents collapse of the tubing. The Wood’s metal is then removed by heating, often by boiling in water. Other uses include making custom-shaped apertures and blocks (for example, electron-beam cutouts and lung blocks) for medical radiation treatment, and making metal inlays in wood. Wood’s metal is also useful for repairing antiques. For example, a bent piece of sheet metal may be repaired by casting a Wood’s metal die from a good example. The low
