Metal Inert Gas welding - also known as gas metal arc welding, offers several advantages over stick and oxyacetylene welding:
Because the process uses a shielding gas, the welding process does not require a flux or another slag forming agent to prevent slag formation within or on top of the weld. Because the joint produced is clean, multiple welding passes can be performed without stopping for surface preparation.
The MIG process also supplies a continuous electrode to the work surface, increasing the length of possible welds and operation speed. These characteristics make the process well suited to automation.