The reversal of current in an AC circuit virtually eliminates arc blow.

The reversal of current in an AC circuit virtually eliminates arc blow.

• A. True
• B. False
• C. Not sure
• D. It depends on electrode

Answer: (A)

Arc blow comes from magnetic fields created by the welding current and the return path, which can push the arc off the joint. With direct current, that magnetic field stays in one direction and can cause a persistent arc drift. When current is alternating, the polarity reverses rapidly, so the magnetic field also flips and the forces on the arc cancel out on average. That cancels the steady deflecting pull, greatly reducing arc blow and often making it virtually vanish under typical AC welding conditions. In practice, only extreme magnetization or unusual grounding arrangements might still show some arc movement.

Arc blow comes from magnetic fields created by the welding current and the return path, which can push the arc off the joint. With direct current, that magnetic field stays in one direction and can cause a persistent arc drift. When current is alternating, the polarity reverses rapidly, so the magnetic field also flips and the forces on the arc cancel out on average. That cancels the steady deflecting pull, greatly reducing arc blow and often making it virtually vanish under typical AC welding conditions. In practice, only extreme magnetization or unusual grounding arrangements might still show some arc movement.