Abstract: A method and apparatus for reducing "arc blow" in multi-electrode welding of a metallic workpiece. Arc blow is produced by interaction between the magnetic fields produced by the closely spaced arcs and electrodes, and takes the form of the end arcs being attracted inwardly towards the others. This reduces the welding efficiency and the maximum welding speed. The invention reduces or eliminates the arc blow by providing shunts made of magnetically permeable material close to the arc-producing ends of the electrodes at the two ends of the row of electrodes. This reduces the concentration of magnetic flux in these regions and reduces the deviation of the end arcs. The invention can be applied wherever multi-electrode welding is used, but is especially useful when the workpiece is made of aluminum as arc blow is a particular problem with this metal.