When the trigger is pulled, the pre-gas starts. When the wire touches the workpiece, a pulse initiates the arc and the welding cycle starts. When the
trigger is released, the wire feeding stops and a current pulse cleanly cuts the wire, followed by the post-gas. As long as the post-gas has not finished,
pressing the trigger will allow a quick restart of the weld (manual chain stitch) without going through the HotStart phase. A HotStart and/or a crater
filler can be added to the cycle.
Standard 4T process:
T hotstart
Dstart
4T
Soft-start
In a standard 4T process, the timing of pre-gas and post-gas is managed automatically. HotStart and crater filler are both controlled by the trigger.