What are the causes of an unstable arc, and how can I remedy them?
• Using the wrong size tungsten, whether in AC or DC applications, is one of the more common causes of an unstable arc. • If the tungsten is too large for the amperage, the arc may rotate around the end of the tungsten. • If the tungsten is too small for the amperage, the current can melt the electrode and cause an erratic arc. • Contaminated tungsten—caused by debris on the base metal, oxidation from inadequate shielding gas, or gas impurities from a leak—also can cause an unstable arc in both AC and DC applications.
