Post-weld cooldown, which interior maintenance step is recommended?

• A. Sand the mold interior lightly.
• B. Leave the mold as is to save time.
• C. Repaint the interior surface for corrosion protection.
• D. Clean the inside of the mold with a soft bristle brush or soft cotton cloth.

Answer: (D)

After cooldown, the interior should be cleaned to remove slag, oxide scale, oil, and dust that could contaminate the next weld or promote corrosion. Using a soft bristle brush or soft cotton cloth gently lifts and wipes away debris without scratching the surface or introducing new particles, keeping the mold interior clean and ready for the next cycle.

Sanding the interior can scratch or embed abrasive material, potentially altering surface finish and leaving behind contaminants. Leaving the mold as is allows residues to linger and may lead to defects. Repainting the interior introduces coatings that could trap moisture or incompatible substances, affecting weld quality and surface behavior.