Miller Dynasty 300 SD Owner's Manual page 53

Trouble
Wandering arc g
Tungsten electrode oxidizing and not re- Increase postflow time.
g g
maining bright after conclusion of weld.
Use proper size tungsten.
Use properly prepared tungsten.
Reduce gas flow rate.
Check and tighten all gas fittings.
Water in torch. Refer to torch manual.
Remedy
OM-358 Page 47