The final step after finishing the weld and allowing the mold to cool is to what?

• A. Reapply coolant to the mold.
• B. Submerge the mold in solvent to remove residues.
• C. Clean the inside of the mold with a soft bristle brush or soft cotton cloth.
• D. Apply a fresh release agent to the mold surface.

Answer: (C)

After welding and letting the mold cool, you want to remove any slag, spatter, and residues from the interior. This cleaning step prevents contaminants from causing defects in the next part and helps ensure the mold surface remains smooth and true to size for proper release. Using a soft bristle brush or a soft cotton cloth is ideal because it lifts and wipes away debris without scratching or dulling the mold’s interior, protecting its finish and coatings. Other options—reapplying coolant, submerging in solvent, or applying a new release agent right away—aren’t the right final post-weld step, as they can introduce moisture, residue, or unnecessary changes to the mold surface or setup.