OM-235 816 Page 7
Trouble
Remedy
Wandering arc
Shield weld zone from drafts.
Reduce gas flow rate.
Select proper size and type of tungsten. Properly prepare tungsten according to Section 6.
When using AC, check welding power source High Frequency control setting, and increase setting if nec-
essary.
Yellow powder or smoke on cup.
Use proper type shielding gas.
Check for proper gas flow rate. Check manufacture’s recommendations.
Increase postflow time.
Check torch cup size. Match cup size to joint being welded.
Erratic arc
Make sure base material is clean and free of contaminates.
When using DC, check polarity, and/or polarity of welding cables.
Select proper size and type of tungsten. Properly prepare tungsten according to Section 6.
Use proper arc length. Arc length may be too long or too short.
When using AC, check welding power source High Frequency control setting, and be sure it is operating
continuously.
When using AC, slow travel speed can cause erratic arc. Adjust travel speed.
Porosity in weld.
Check for proper type gas and correct flow rate. Check manufacture’s recommendations.
Check and tighten gas fittings.
Make sure base material and filler material is clean and free of contaminates.
Check for impurities and moisture in gas lines. Purge if necessary.
If torch is water cooled, check torch and cables for water leaks. Repair or replace if necessary (see Sec-
tion 4-1).
