What happens if the shielding gas coverage is inadequate during MIG welding?

Inadequate shielding gas coverage during MIG welding can lead to oxidation and poor weld quality because the primary purpose of the shielding gas is to protect the molten weld pool from atmospheric contaminants, particularly oxygen and nitrogen. When the shielding gas coverage fails to provide a sufficient barrier, these elements can react with the molten metal, resulting in oxidation. This reaction affects the integrity of the weld, causing issues such as porosity, reduced strength, and overall weak weld characteristics. A well-protected weld pool ensures a cleaner, stronger bond between the base metals, contributing to a higher-quality weld. Therefore, sufficient shielding gas coverage is crucial for achieving optimal results in MIG welding.