Mig Question

[Haz]

I know there are four different modes of mig welding: short circuit,spray-arc transfer, globular transfer, and pulsed-spray arc transfer. What determines the mode you're in? Is it the voltage and wire speed? Are most machines capable of doing each mode? Thanks, Bruce

[Paul Seaman]

Pulse is a feature of the equipment, and spray uses 98/2 gas, and short circuit is the base setup, and globular is the process just below spray when the gas just isn't hot enough to push into the spray mode.

This is the over simplified version, I can get more detailed but not enough time right now.

[imported_Slag]

And to add to the question, when would you want to use one method over another.

[Alex]

Modes

Pulse for thin stuff (less heat input).
Spray is only for flat horizontal position. Won't work on out-of-position stuff.
Globular transfer = who cares (it's a mess because of all the spatter).
Short arc = everything else.

[hankj]

Spray-arc requires higher voltages and currents and argon-rich shielding gas. Depending on welder power, 86/14, 90/10, and 98/2 will spray. Spray is usually used on thicker sections - 1/4" and up. Spray is the most commonly used industrial process due to the high deposition rate it achieves. You'd need a power source that can run ~26 volts at 180 - 200 amps to spray with 98/2, and higher voltages to spray with less argon in the mix.

Hank