What is the result of insufficient gas coverage?

• A. Porosity
• B. Spatter
• C. Cracking
• D. Undercut

Answer: (A)

When shielding gas doesn’t fully cover the weld area, the molten pool is exposed to air. The shielding gas is meant to protect the molten metal from oxygen and other atmospheric gases. Without enough coverage, gas pockets form as the metal solidifies, creating porosity—small hollow holes inside the weld. This weakens the weld and can cause leaks or reduced strength.

Spatter is more about droplets being expelled from the arc due to arc length, current, or technique issues, not a direct result of insufficient shielding. Cracking comes from stresses and cooling conditions, while undercut is a groove along the weld toe caused by other parameter issues. So the key effect of insufficient gas coverage is porosity in the weld.