Which of the following are listed as ways to remove tungsten contamination?

• A. Grinding, chemical cleaning, breaking, chemical cleaning and pointing, pointing and remelting
• B. Grinding and cleaning only
• C. Sanding and filing
• D. Ultrasonic cleaning

Answer: (B)

Tungsten contamination on the electrode tip must be removed to prevent it from entering the weld and causing defects. The most effective approach is to grind away the contaminated portion of the tungsten and then clean the surface to remove any residues. Grinding physically eliminates the material that’s tainted, exposing fresh tungsten, while cleaning ensures any oils, fingerprints, or debris are gone so the arc can behave properly.

Other options don’t fit well because they either don’t reliably remove the contamination or can introduce new problems. Breaking or remelting the tip can create more tungsten fragments that may contaminate the weld or alter the electrode geometry in unpredictable ways. Pointing or sharpening isn’t about removing contamination and can leave particles or create irregularities. Sanding and filing may transfer grit or fail to remove embedded contamination. Ultrasonic cleaning alone targets surface dirt but doesn’t adequately address tungsten contamination on the electrode itself.

So grinding the contaminated portion followed by cleaning provides the appropriate, straightforward way to restore a clean electrode tip for GTAW.