What method is used to clean steel before TIG welding?

• A. Wire Brush
• B. Grinder or acetone wipe
• C. Soap and Water
• D. Sandblasting

Answer: (B)

For TIG welding, you want a surface that’s free of oxides and oils so the weld can fuse cleanly. Using a grinder to remove rust, scale, and coatings exposes fresh metal, giving a solid base for the weld. If the surface is just contaminated with oil or grease, wiping with acetone is effective because acetone dissolves oils and evaporates quickly without leaving residue. This combination directly targets the contaminants that cause porosity and weak welds.

Other methods aren’t as reliable here. A wire brush can leave oxide particles behind or introduce contamination if the brush isn’t clean or is a different metal, and it may not remove heavy scale effectively. Soap and water leaves moisture and potential residues that can interfere with the weld. Sandblasting is too aggressive and can embed abrasive particles or roughen the surface, requiring extra cleaning. So grinding or acetone wiping addresses the most common prep needs for a clean TIG weld surface.