Weld Mold 755 description: A specially alloyed copper-nickel product that produces porosity free weld deposits on low grade cast iron castings and patterns. Weldments can be machined through the heat affected zone. Excellent for repairing all types of cast iron parts such as molds, castings, and patterns when a close color match is required. Weld Mold 755 can also be used as a first layer on high sulfur steels.