Yellowish residue /
smoke on the
alumina nozzle &
discoloured tungsten
Incorrect Gas
Use pure Argon gas
Inadequate gas flow
Set the gas flow between 10 - 15 l/min
flow rate
Alumina gas nozzle too small
Increase the size of the alumina gas
nozzle
Unstable Arc during
DC welding
Torch connected to DC +
Connect the torch to the DC- output
terminal
Contaminated base metal
Remove materials like paint, grease,
oil, and dirt, including mill scale from
base metal.
Tungsten is contaminated
Remove 10mm of contaminated
tungsten and re grind the tungsten
Arc length too long
Lower torch so that the tungsten is off
of the work piece 2 - 5mm
Arc wanders during
DC welding
Poor gas flow
Check and set the gas flow between 10
- 15 l/min flow rate
Incorrect arc length
Lower torch so that the tungsten is off
of the work piece 2 - 5mm
Tungsten incorrect or in poor
condition
Check that correct type of tungsten is
being used. Remove 10mm from the
weld end of the tungsten and re sharpen
the tungsten
Poorly prepared tungsten
Grind marks should run lengthwise
with tungsten, not circular. Use proper
grinding method and wheel.
Contaminated base metal or
filler wire
Remove contaminating materials like
paint, grease, oil, and dirt, including
mill scale from base metal. Remove all
grease, oil, or moisture from filler metal
Arc difficult to start
or will not start DC
welding
Incorrect machine set up
Check machine set up is correct
No gas, incorrect gas flow
Check the gas is connected and cylinder
valve open, check hoses, gas valve and
torch are not restricted. Set the gas flow
between 10 - 15 l/min flow rate
Incorrect tungsten size or type
Check and change the size and or the
tungsten if required
Loose connection
Check all connectors and tighten
Earth clamp not connected to
work
Connect the earth clamp directly to the
work piece wherever possible