Electrode having a nickel-copper core wire for welding cast iron with preheating. Iron admixture from base metal should be kept low. Well-suited to welding cast iron with lamellar graphite, white, and black heart malleable cast iron, nodular cast iron. Weld metal closely matches colour of base metal. Thus electrode is preferably used for making filler and cover passes or for filling-up shrinkage cavities. Provides easy arc striking and restriking and stable arc. Weld metal is machinable. Weld short beads, about 30 to 50 mm long. In order to reduce weld residual stresses, hammer-peen welds slightly before cooling.