PC Polish/Cleaner Compound, 43310, is also known as “Old Yellow” and can be used on all metal molds to remove stains and discoloration. It is a water-based liquid mold cleaner that is formulated to be used on cold or warm molds. PC leaves a non-transferring, micron-thin film that helps reduce mold wear. Regular use of PC reduces the need for all types of internal and external mold release agents by conditioning your mold for faster startups and improved release properties.