Dull, gray bead indication?

• A. Poor gas shielding or contamination
• B. Excellent weld
• C. Too fast travel
• D. Small bead

Answer: (A)

In TIG welding, how the weld bead looks is a direct clue about shielding effectiveness and contamination. A dull, gray bead signals oxidation of the molten metal, which happens when shielding gas isn’t protecting the puddle adequately or when contaminants are present. If the gas flow is too low, there’s a leak, or the nozzle is positioned poorly, the arc is exposed to air and oxide forms, giving a dull, gray appearance instead of a bright, clean finish. Contaminants—oil, grease, dirt, moisture, or dirty filler metal or tungsten—can also introduce oxides as the weld cools, producing that same dull look. To address this, ensure shielding gas is on before striking and maintained across the weld with proper flow, inspect for leaks, and clean and dry all workpieces and materials before welding. The other descriptions would lead to different bead characteristics—travel speed or heat input affecting bead size or fusion—not specifically the oxidation tone seen with inadequate shielding or contamination.