A welding arc stabilizer including a source of high voltage and a switch for switching the source of high voltage across the electrode and the workpiece in the event the arc rectifies. The high voltage is switched across the electrodes within the completion of the half cycle in which rectification occurred. The source of high voltage includes a resonant LC circuit. An arc sensing circuit, including a resistor, a capacitor, and a zener diode is provided in parallel with the arc. In the event the voltage applied to the electrode and workpiece exceeds the zener diode breakdown voltage, indicating the arc has rectified, an SCR disposed between the resonant circuit and one of the electrode and the workpiece is turned on, thus connecting the source of high voltage to the electrode and workpiece.