Weld Mold 4067 description: Weld Mold 4067 is a high copper material for joining dissimilar combinations of copper and nickel alloy materials. Weld Mold 4067 is for welding Monel alloy 450 and other copper-nickel alloys. Weld Mold 4067 is widely used in marine applications because of its excellent resistance to seawater-induced corrosion. This product will also join many dissimilar combinations of Monel, Nickel 200 and various copper-nickel alloys.