With 1% and 2% thoriated tungsten electrodes, arc starting is easier and wider current ranges can be used.
This is due to the addition of thoria. Thoria will not become molten, and it reduces the tendency of the electrode to stick
or freeze to the work. A 2% thoriated tungsten electrode has a longer life due to the added thoria. Thoriated tungsten electrodes
have a higher resistance to contamination on AC and DC settings and will not cause contamination if accidentally touched to the work.
Pure tungsten electrodes provide good arc stability. They have clean balled ends for AC welding with reasonably g o o d resistance to
contamination. Zirconium tungsten electrodes are used primarily for the welding of nuclear components. They provide minimal tungsten