Tig Welding Trouble Shooting - Unimig VIPER Operating Manual

TIG WELDING TROUBLE SHOOTING

The following chart addresses some of the common problems of DC TIG welding. In all cases of equipment malfunction, the manufacturer's
recommendations should be strictly adhered to and followed.
1: Tungsten burning away quickly
Possible Reason
Incorrect Gas or No Gas
Inadequate gas flow
Back cap not fitted correctly
Torch connected to DC +
Incorrect tungsten being used
Tungsten being oxidised after weld is
finished
2: Contaminated tungsten
Possible Reason
Touching tungsten into the weld pool
Touching the filler wire to the tungsten
3: Porosity - poor weld appearance and colour
Possible Reason
Wrong gas / poor gas flow /gas leaks
Contaminated base metal
Contaminated filler wire
Incorrect filler wire
4: Yellowish residue / smoke on the alumina nozzle & discoloured tungsten
Possible Reason
Incorrect Gas
Inadequate gas flow
Alumina gas nozzle too small
5: Unstable Arc during DC welding
Possible Reason
Torch connected to DC +
Contaminated base metal
Tungsten is contaminated
Arc length too long
6: Arc wanders during DC welding
Possible Reason
Poor gas flow
Incorrect arc length
Tungsten incorrect or in poor condition
Poorly prepared tungsten
Contaminated base metal or filler wire
7: Arc difficult to start or will not start DC welding
Possible Reason
Incorrect machine set up
No gas, incorrect gas flow
Incorrect tungsten size or type
Loose connection
Earth clamp not connected to work
42 | VIPER MIG 185 Manual
Suggested Remedy
Use pure Argon. Check cylinder has gas, connected, turned on and torch valve is open
Check the gas is connected, check hoses, gas valve and torch are not restricted.
Make sure the torch back cap is fitted so that the O-ring is inside the torch body
Connect the torch to the DC- output terminal
Check and change the tungsten type if necessary
Keep shielding gas flowing 10–15 seconds after arc stoppage. 1 second for each 10 amps of weld
current.
Suggested Remedy
Keep tungsten from contacting weld puddle. Raise the torch so that the tungsten is off of the work
piece 2 - 5mm
Keep the filler wire from touching the tungsten during welding, feed the filler wire into the leading
edge of the weld pool in front of the tungsten
Suggested Remedy
Use pure argon. Gas is connected, check hoses, gas valve and torch are not restricted. Set the gas
flow between 6-12 l/min. Check hoses and fittings for holes, leaks etc.,
Remove moisture and materials like paint, grease, oil, and dirt from base metal
Remove all grease, oil, or moisture from filler metal.
Check the filler wire and change if necessary
Suggested Remedy
Use pure Argon gas
Set the gas flow between 10 - 15 l/min flow rate
Increase the size of the alumina gas nozzle
Suggested Remedy
Connect the torch to the DC- output terminal
Remove materials like paint, grease, oil, and dirt, including mill scale from base metal.
Remove 10mm of contaminated tungsten and re grind the tungsten
Lower torch so that the tungsten is off of the work piece 2 - 5mm
Suggested Remedy
Check and set the gas flow between 10 - 15 l/min flow rate
Lower torch so that the tungsten is off of the work piece 2 - 5mm
Check that correct type of tungsten is being used. Remove 10mm from the weld end of the tungsten
and re sharpen the tungsten
Grind marks should run lengthwise with tungsten, not circular. Use proper grinding method and
wheel.
Remove contaminating materials like paint, grease, oil, and dirt, including mill scale from base metal.
Remove all grease, oil, or moisture from filler metal.
Suggested Remedy
Check machine set up is correct
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
Check and change the size and or the tungsten if required
Check all connectors and tighten
Connect the earth clamp directly to the work piece wherever possible