To reduce arc blow, which clamp placement is correct?

• A. Place the clamp near the joint
• B. Place the clamp on the ground strap
• C. Place the clamp on the electrode holder
• D. Place the clamp far from the joint

Answer: (D)

Arc blow comes from the magnetic field created by the welding current, and where the return current travels changes that field around the weld. Placing the ground clamp far from the joint makes the return path more spread out and less concentrated right at the weld area, so the magnetic forces don’t push the arc off course as easily. If the clamp is near the joint, the return current is concentrated close to the weld, which strengthens the local magnetic field and can cause the arc to wander. Grounding the clamp on the ground strap or on the electrode holder doesn’t provide the optimal return path for minimizing that localized magnetic effect, so they’re less effective. Therefore, keeping the clamp far from the joint helps reduce arc blow.