Patent ID: 8129652

Claim:
A method of controlling a mixture of arc shielding gas during an arc welding operation, the method comprising the steps of: (a) actuating a first valve connected to a first source of gas to selectively allow a first gas mixture to flow from the first source of gas into a mixing chamber and then into a weld gun; (b) actuating a second valve connected to a second source of gas to selectively allow a second gas mixture, which is different from the first gas mixture, to flow from the second source of gas into the mixing chamber and then into the weld gun; (c) conducting the arc welding operation; (d) monitoring at least one weld parameter to detect arc instability during the arc welding operation; (e) communicating the at least one weld parameter being monitored to a controller; and (f) during the arc welding operation, automatically actuating the first and second valves with the controller when arc instability is detected during the arc welding operation to adjust the first gas mixture flowing from the first source of gas and the second gas mixture flowing from the second source of gas, respectively.