Method and apparatus for welding

A method of MIG welding comprising:

• providing ac power to a weld, wherein the ac power has a negative portion and a positive portion, and the ac power further has a frequency;
• and
• providing at least one workpiece with a weld path thereon, wherein the weld path includes a groove having an angle of less than 50 degrees.

A method of MIG welding comprising:

• providing ac power to a weld having a negative portion and a positive portion, and the ac power further having a frequency;
• and
• providing a consumable, cored, wire to the weld.

32-38. (Cancelled.)

A method of MIG welding comprising:

• providing ac power to a weld having a negative portion and a positive portion, and the ac power further having a frequency;
• and
• wherein the negative portion is at least 1.5 times the positive portion.

(Cancelled.)

A MIG welding system comprising:

• power means for providing ac power to a weld, wherein the ac power has a negative portion and a positive portion, and the ac power further has a frequency;
• and
• control means for controlling the power means, wherein the negative portion has a negative amp-seconds and the positive portion has a positive amp-seconds, wherein the control means causes the negative amp-seconds to be greater than the positive amp-seconds, and wherein the frequency is at least 60 Hz.

A system of MIG welding arc comprising:

• power means for providing to a weld ac power having a negative portion and a positive portion, and the ac power further having a frequency;
• and
• means for providing a consumable, cored, wire to the weld.

A system of MIG welding comprising:

• power means for providing ac power to a weld, the ac power having a negative portion and a positive portion, and the ac power further having a frequency;
• and
• means for controlling the power means such that the negative portion is at least 1.5 times the positive portion.

A system of MIG welding comprising:

• power means for providing ac power to a weld, wherein the ac power has a negative portion and a positive portion, and further has a frequency;
• control means for controlling the power means such that the negative portion is greater than the positive portion, and further such that the weld process begins with the negative portion for at least 0.5 seconds.

A system of MIG welding comprising:

• power means for providing ac power to a weld, wherein the ac power has a negative portion and a positive portion, and further has a frequency;
• control means for controlling the power means such that the negative portion has a negative amp-seconds and the positive portion has a positive amp-seconds, and further wherein the magnitude of the negative amp-seconds is greater than the magnitude of the positive amp-seconds.

75-78. (Cancelled.)

A system of MIG welding comprising:

• an ac power source having a control input and a MIG output, wherein the MIG output has a negative portion and a positive portion;
• a controller, including a balance circuit and a feedback circuit, operatively connected to the control input such that the negative portion is at least 1.5 times the positive portion.

A method of controlling dilution in MIG welding comprising:

• providing ac power to a weld, wherein the ac power has a negative portion and a positive portion, and the ac power further has a frequency;
• controlling the balance of the negative portion and the positive portion to obtain a desired dilution.