The standard post-weld care step for the mold interior after it has cooled is to:

• A. Replace the mold with a new unit.
• B. Clean the inside of the mold with a soft bristle brush or soft cotton cloth.
• C. Repaint the interior surface.
• D. Decontaminate the exterior with a solvent.

Answer: (C)

After welding, the interior surface has been exposed to heat that can cause oxidation and damage to any existing coating. Repainting the interior provides a fresh, protective coating that guards against moisture, corrosion, and chemical attack during use. It also helps restore a smooth, uniform surface finish, which improves mold release and reduces the chance of residues sticking to rough spots. Replacing the mold is unnecessary for a routine weld; simply cleaning doesn’t restore the protective layer, and decontaminating the exterior doesn’t address interior protection. Use a heat- and chemically resistant coating that’s compatible with the mold material and cure it per specifications before putting the mold back into service.