Weld Mold 4190 description: Weld Mold 4190 is a nickel-copper premium quality electrode with excellent operating characteristics. This electrode is used when seawater induced corrosion is a problem, and also for stress corrosion cracking in reducing acids and salts. Applications include the welding of Monel 400, 404 and 405. 4190 is also used for welding of copper nickel alloys of similar analysis. Dissimilar weld applications include the surfacing of nickel-copper alloys to steel and dissimilar alloys of nickel-copper to steel.