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Welder Red Seal · Question

A welder is setting up for GTAW on a 6 mm thick aluminum plate using AC current. They observe that the tungsten electrode is eroding quickly and forming a large, uneven ball on the tip. What is the most likely cause of this issue?

A tungsten electrode that is too small in diameter for the welding current will overheat, causing excessive erosion and an unstable, overly large ball. Proper e

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Question: A welder is setting up for GTAW on a 6 mm thick aluminum plate using AC current. They observe that the tungsten electrode is eroding quickly and forming a large, uneven ball on the tip. What is the most likely cause of this issue?

Answer options: ✅ The electrode diameter is too small for the welding current.

  • The shielding gas flow rate is too high.
  • The tungsten electrode type is ceriated (non-AC specified).
  • The AC balance control is set too high for penetration.

Correct answer: The electrode diameter is too small for the welding current.

Explanation: A tungsten electrode that is too small in diameter for the welding current will overheat, causing excessive erosion and an unstable, overly large ball. Proper electrode sizing is critical to prevent premature tungsten degradation.

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