Arc Blow - The unwanted deflection or the wandering of a welding arc from its intended path is termed as arc blow or arc bow. Arc blow is the result of magnetic disturbances which unbalance the symmetry of the self induced magnetic field around the electrode, arc and workpiece.
Under arc blow, an arc may distort, deflect or rotate. Arc blow becomes severe when welding is carried out in confined spaces and corners on heavy metal plates, using a DC power source. AC arcs are less susceptible to arc blow than DC arcs; because the alternating current reverses direction which in turn reverses the magnetic field.
