Why MIG Welds Get Porosity & How to Fix It

Intro Porosity — tiny gas pockets trapped inside your weld bead — is a frequent headache for MIG welders. It weakens joints and ruins the look of your finished work. We’ll walk through the root causes of MIG porosity and show you how to prevent and repair defective welds.

Body

• What weld porosity is
• Top causes: contaminated metal surface, bad gas coverage, leaks in the gas hose, wrong wire speed, dirty liner
• How to identify porosity on the surface and inside the weld
• Repair procedure: grind out all porous material completely, re-clean, re-weld
• Preventive checklist before striking an arc

Closing Most porosity issues come from simple prep mistakes. Clean metal and consistent gas flow are your best defense against voids in your MIG welds.