Which contamination-removal method specifically involves pointing and re-melting the tungsten end?

• A. Grinding
• B. Pointing and remelting
• C. Chemical cleaning
• D. Breaking

Answer: (B)

Pointing and remelting is the method that reconditions the tungsten by melting the tip and letting it resolidify into a clean, sharp point. When the electrode tip becomes contaminated with oxides or residues, simply grinding or breaking only removes or alters material but doesn’t guarantee a fresh, uncontaminated surface right at the active end. By melting the end and re-forming it, you effectively purge surface contaminants and restore a smooth, pointed geometry that concentrates the arc and improves stability and control. This is why, for contamination at the tip itself, pointing and remelting specifically targets removing the contaminant at the very end of the electrode. Grinding can remove surface material but risks embedding particles and changing diameter; chemical cleaning removes some residues but may not clean oxides on the tungsten; breaking removes a portion without reestablishing a proper pointed end.