Welding is a ubiquitous method of metalworking that joins two pieces of metal together to form a strong bond. But what exactly happens when the two metals join together? By definition, welding joins two pieces of metal by fusion. In order to properly fuse together, the base metal must melt and flow together. Older welding methods would employ an oxyfuel blowtorch to heat pieces of metal until the base metals reached melting temperature, but newer methods now use an electric arc to generate the heat necessary to melt the metal. The arc is created when an electric charge is passed from an electrode to the workpieces. The electrode is usually consumable and charged either negatively or positively depending on the desired character of the weld. A proper weld often creates a bond between workpieces that is stronger than the original strength of the workpieces themselves.