What are proper base-metal preparation steps prior to GTAW, including cleaning and fit-up?

What are proper base-metal preparation steps prior to GTAW, including cleaning and fit-up?

• A. Remove oil/grease, scale, and oxides; de-burr and square edges; ensure clean, dry surfaces; fit up with minimal gap and secure alignment; use dedicated brushes or grinders for different metals.
• B. Rinse with water and wipe dry; no scrubbing.
• C. Only clean with water after assembly.
• D. Do not deburr or square edges.

Answer: (B)