What is the main difference between MIG welding and flux core arc welding?

The main difference between MIG (Metal Inert Gas) welding and flux core arc welding lies in the presence of flux in the wire. In MIG welding, a solid metal wire is used, and an external shielding gas is required to protect the weld pool from contamination. This means that the quality of the weld is significantly influenced by the type of shielding gas used, often argon or a mix of argon and carbon dioxide.

In contrast, flux core arc welding utilizes a tubular wire filled with flux. When the flux core is heated during the welding process, it produces a shielding gas and a slag that protects the weld pool from atmospheric contamination. This self-shielding capability allows for welding in outdoor environments and on materials that may be dirty or rusty, where external shielding gas could be less effective.

While other factors like shielding gas, electrode consumption, and power sources can vary between the two processes, the defining characteristic is indeed the use of flux in the wire for flux core arc welding, making it suitable for varies applications where MIG welding may not be feasible.