What is arc blow, and what practical steps help prevent it in a shop?

What is arc blow, and what practical steps help prevent it in a shop?

• A. Arc blow is arc wandering caused by magnetic fields; preventing measures include proper grounding.
• B. Arc blow is caused by insufficient shielding gas.
• C. Arc blow is arc wandering due to magnetic fields; prevent by proper grounding, avoiding close parallel power lines, and repositioning the work or ground.
• D. Arc blow is the weld turning black.

Answer: (C)

Arc blow happens when the welding arc wanders because of magnetic fields around the current path. When there are strong magnetic fields from nearby energized conductors or a long, loose ground lead, the arc can be pushed away from the weld joint, making it difficult to control and producing an inconsistent bead. To prevent arc blow in a shop, use a solid, close ground connection and keep the ground clamp as near the weld as possible. Shorten and route the ground lead to minimize its magnetic influence, and avoid having large current-carrying conductors running parallel to the weld area. If needed, reposition the work or adjust the ground placement to place the arc away from strong magnetic fields. Issues like insufficient shielding gas or the weld turning black are not related to arc blow.

Arc blow happens when the welding arc wanders because of magnetic fields around the current path. When there are strong magnetic fields from nearby energized conductors or a long, loose ground lead, the arc can be pushed away from the weld joint, making it difficult to control and producing an inconsistent bead.

To prevent arc blow in a shop, use a solid, close ground connection and keep the ground clamp as near the weld as possible. Shorten and route the ground lead to minimize its magnetic influence, and avoid having large current-carrying conductors running parallel to the weld area. If needed, reposition the work or adjust the ground placement to place the arc away from strong magnetic fields. Issues like insufficient shielding gas or the weld turning black are not related to arc blow.