What is the recommended practice for restarting a welding arc after a brief power interruption?

• A. Continue welding from where you left off without re-striking.
• B. Stop and re-ignite at a different crater.
• C. Switch to a different joint.
• D. Re-establish the arc by re-striking at a clean location and ensure the crater is filled before continuing.

Answer: (C)

When restarting a GMAW arc after a brief power interruption, re-strike at a clean location and ensure the crater is filled before continuing. This approach keeps the weld sound and uniform. If you resume from the same spot without re-striking, you risk a weak tie-in where the old crater meets the new weld, which can lead to crater cracks, porosity, or poor fusion. Starting at a clean spot avoids contamination from the cooled, oxidized metal at the crater and helps maintain a stable arc and proper heat input as you continue the weld. Filling the crater before continuing ensures a smooth, continuous bead and reduces the chance of defects at the end of the restart.