Gas metal arc welding (GMAW) is a widely used process for joining metals. Its main advantage over its competition gas tungsten arc welding (GTAW) is its high productivity in depositing metals. However, to melt metal from the wire to deposit into the work-piece, additional heat is consumed and applied to the work-piece with an uncontrolled fixed proportion to the effective heat that melts the wire. Such additional heat is often in excess of the needed heat input for the work-piece. The side-effects include a waste of the energy, an increased distortion, and possible materials property degradation. This invention is to device a method to transfer this part of heat to melt the wire by adding two wires, which form a pair of arc spots, under a tungsten arc. It also devices a method to assure the arc between the two wires be maintained stable such that the transfer be successfully continuous. The successful continuous transfer improves the energy efficiency, eliminates the adverse effects on the distortion and materials property, and decouples the controls on mass input and heat input on the work-piece.