Following the cooling period post-weld, what routine should be performed on the mold interior?

• A. Wipe the exterior with a dry cloth.
• B. Clean the inside of the mold with a soft bristle brush or soft cotton cloth.
• C. Rinse the mold with solvent and air dry.
• D. Repaint the mold interior.

Answer: (B)

Cleaning the mold interior after the weld has cooled is important to remove any weld residue, scale, or spatter that could affect the next cycle. Performing this routine during the cooling period helps preserve the interior surface finish and geometry, which are essential for consistent part quality and smooth release.

Using a soft bristle brush or a soft cotton cloth is ideal because these tools remove debris without scratching or altering the delicate interior surface. Harsh tools or solvents can damage the mold or leave residues that pollute subsequent cycles, and repainting would unnecessarily alter the surface and require additional processing. Wiping the exterior doesn’t address interior cleanliness, and rinsing with solvent could introduce residue or damage the mold material.

So, the safest and most effective practice is to gently clean the inside with a soft brush or cloth to keep the mold ready for the next cast or form.