MIG welding (gas metal arc welding) offers the benefit of allowing long welds without frequent starting and stopping. MIG welding results in clean, uniform welds. TIG welding (gas tungsten arc welding) can be performed with a fill-metal like in MIG welding or without a fill-metal. No spatter is produced in TIG welding.
Shielding gases control erratic arc movement and keep weld sites clear of contaminants. Shielding gases also contribute to higher-quality welds and welds that are smoother in appearance. Argon gas is used in welding alone or in combination with helium, hydrogen, carbon dioxide or oxygen.
Argon is combined with carbon dioxide, oxygen or helium for MIG welding. In TIG welding, argon is paired with helium or hydrogen. The reason behind argon-based shielding-gas technology remains that argon provides a cleaning action unparalleled to any other gas that is safe for welding applications. Oxygen and helium improve welding penetration when combined with argon.