Weldclass WeldForce WF-205MST, Operating Instructions Manual

Page: 15 / 80

WF-205
MST
© Weldclass 2019 | E.&O.E. | Edition 2.1 15
4.3.1 Pre-Gas Time (MIG)
Pre-Gas (or Pre-Flow) setting is adjustable from 0 – 2 seconds. This controls the period shielding gas will
flow for when the torch is triggered before the arc starts. This purges the weld zone of atmospheric gas
which could contaminate the weld before the weld starts. In most common welding applications pre-gas is
not critical and can be set to 0.
4.3.2 Post-Gas Time (MIG)
Post-Gas (or Post-Flow) setting is adjustable from 0 – 5 seconds. This controls the period of time the
shielding gas continues to flow after the arc has stopped. This protects the weld area from contamination
while it is still hot enough to react with atmospheric gases, after the weld is finished/trigger is released. In
most common welding applications post-gas is not critical and can be set to 0.
4.3.3 Soft-Start Adjustment (MIG)
Soft-Start setting is adjustable on a scale 0 – 5. Sometimes known as ‘hot start’ or ‘slow feed’. When a weld
is started, the workpiece and the wire will be ‘cold’ compared to welding temperature. This can cause an
uneven and poor start to the weld using the voltage and wire feed speed selected as optimal once the arc
is established. This setting slows the wire speed down at the start of the weld which improves the weld
starting performance. If you find the wire ‘bumping’ the workpiece before the arc is fully established try
increasing Soft-Start setting.
4.3.4 Burnback Adjustment (MIG)
Burn-back setting is adjustable on a scale 0 – 5. Burnback adjustment controls the short period of time that
the wire feed will continue to run for after the main welding current stops. If the wire feed and current is
stopped at exactly the same time, the wire will still be hot and will ‘burn’ back and stick to the welding tip.
If this problem is happening, increasing the burnback adjustment will cause the wire feeder to run for longer
after the arc has stopped. If the burnback adjustment is excessive, after a weld has stopped, the operator
will be left with excess ‘stick out’ wire length from the torch tip that will require correcting before starting
the next weld.
4.3.5 Spot/Stitch Weld Time (MIG)
This setting will ONLY be accessible when Trigger Mode is set to ‘Spot Welding’.
Spot/Stitch Weld Time setting is adjustable from 0 – 5 seconds. This controls the length of time for the weld.
When the trigger is pulled the machine will weld for the set time and then stop. This is great for producing
very precise weld size or ensuring consistent weld size/length when spot welding, tacking or stitch welding.
4.3.6 Stitch Weld Gap/Interval Time (MIG)
This setting will ONLY be accessible when Trigger Mode is set to ‘Spot Welding’ (see 4.4 Trigger Mode
Selection).
Stitch Weld Gas/Interval Time setting is adjustable from 0 – 5 seconds. This controls the length of time
between welds. So when trigger is held on the machine will weld for the ‘Spot/Stitch’ time then it will stop
for the ‘Stitch Weld Gap/Interval’ time and repeat this until the trigger is released. This is great for producing
a very consistent stitch weld or multiple tack welds.
TIP! If you are only doing individual ‘Spot’ welds (single welds, no repeat) it is
suggested to set this Stitch Weld Gap time to maximum and release the trigger before
the weld repeats.