Video
Script
In this video, we take a closer look at an engineering process called arc welding. First, we prepare a welding clamp which is attached to a welding transformer providing a welding current. We use the clamp to connect a sheet metal to the transformer. Before we start welding, it is important to wear welding gloves in order to protect our skin from the high temperature. We also need to wear a welding helmet in order to protect our sight. We are going to use a consumable electrode placed in an electrode holder that is attached to the welding transformer as well. The electric arc is sparked between the sheet metal and the electrode. The arc has temperature of about 4444 °C and welds the work-piece. As the material is being welded, the electrode melts and acts as a filler material. Its flux coating produces a shielding gas which protects the weld against oxidation and contaminants and thus fights porosity and brittleness. If the electrode is completely consumed, we have to replace it with a new one. After we finish welding, we remove the slag which remained on the work-piece. To accomplish that, we usually use a chipping hammer or a chisel. Typically, it is easy to remove the slag since it is not firmly adhered to the surface of the work-piece. To finish up, we use a wire brush to dispose of the remaining slag.