4
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
Inadequate post flow gas
Increase the post flow gas time
Alumina gas nozzle too
small
Increase the size of the alumina gas
nozzle
5
Unstable Arc
during 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
6
HF present but no
welding power
Incomplete welding circuit
Check earth lead is connected.
Check all cable connections. If
using a water cooled torch check
that the power cable is separated.
6
HF present but no
welding power
No gas
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
Tungsten melting into the
weld pool
Check that correct type of tungsten
is being used. Too much current for
the tungsten size so reduce the
amps or change to a larger tungsten
7
Arc wanders
during 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
Incorrect filler wire
Check the filler wire and change if
necessary
8
Arc difficult to
start or will not
start 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
Tungsten is contaminated
Remove 10mm of contaminated
tungsten and regrind the tungsten
Loose connection
Check all connectors and tighten
Earth clamp not connected to
work
Connect the earth clamp directly to
the work piece wherever possible
Loss of high frequency
Check torch and cables for cracked
insulation or bad connections.
