When the arc is powered by a single-phase rectifier with a condenser voltage multiplier using tungsten electrodes with a diameter of 1-2.5 mm, the arc ignites and burns in argon and nitrogen with a current of 4-10 A. Stable arc burning at a reverse polarity provides full penetration of aluminum sheets with a thickness of 0.18-0.5 mm without outflow of a molten pool.

In welding of end connections made of low-carbon steel, stainless steel, copper, brass, aluminum with a thickness of 0.06-0.2 mm, with a gap larger than sheet thickness, in argon and nitrogen of high grade, the weld is formed by cylindrical and rectangular electrode at the current of 2.5-9 A. At these low currents Intensive wandering of the active spots are detected.

Keywords: Mig welding, non-consumable electrode welding, non-consumable electrode, tungsten electrode, aluminum welding, welding in shielding gases, welding arc, nitrogen, weld end connectioin, cylindrical  electrode, rectangular electrode.