Which statement about surface preparation is NOT correct?

• A. It ensures good fusion and reduces porosity; remove oil, rust, paint; degrease.
• B. It is optional if the metal is clean.
• C. It is essential for achieving sound welds and reducing defects.
• D. It requires degreasing and removing contaminants.

Answer: (B)

Surface preparation is about removing contaminants that can block fusion and create defects in the weld. Oils, grease, paint, rust, and moisture can form barriers or introduce porosity and hydrogen-related issues if not removed. Even metal that looks clean can carry residues from handling or storage, so cleaning and degreasing are standard must-dos before welding. Because of this, saying surface preparation is optional if the metal is clean isn’t correct; you still need to remove oils, coatings, and other contaminants to achieve sound welds. The other statements align with this principle: removing oil, rust, and paint and degreasing helps ensure good fusion and reduces porosity; surface prep is essential for sound welds and fewer defects; and it involves degreasing and removing contaminants.