Porosity is one of the most common defects in MIG welding, affecting weld strength, appearance, and reliability. This guide explains how to fix porosity in MIG welding by identifying its leading causes, including inadequate shielding gas, contaminated materials, incorrect welding parameters, moisture, and worn torch consumables. It also provides step-by-step troubleshooting methods, preventive maintenance practices, and professional welding tips to help achieve clean, defect-free welds. Whether you are a welder, fabricator, distributor, or OEM buyer, these proven solutions will improve welding quality, reduce downtime, and enhance long-term production efficiency.