pro.point 8619470 - Page 45

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7: Arc wanders during DC welding
Possible Reason Suggested Remedy
Poor gas ow Check and set the gas ow between 21-30cfh ow rate
Incorrect arc length Lower torch so that the tungsten is off of the work piece 1/8-1/4in
Tungsten incorrect or in poor condi-
tion
Check that correct type of tungsten is being used. Remove 1/2in 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 Remove contaminating materials like paint, grease, oil, and dirt, including mill scale from
base metal.
Contaminated ller wire Remove all grease, oil, or moisture from ller metal.
Incorrect ller wire Check the ller wire and change if necessary
At initial set up and at regular intervals we recommend to check for gas leakage.
Recommended procedure is as follows:
1. Connect the regulator and gas hose assembly and tighten all connectors and clamps.
2. Slowly open the cylinder valve.
3. Set the ow rate on the regulator to approximately 21-30cfh.
4. Close the cylinder valve and pay attention to the needle indicator of the contents pressure
gauge on the regulator, if the needle drops away towards zero there is a gas leak.
Sometimes a gas leak can be slow and to identify it will require leaving the gas pressure in the
regulator and line for an extended time period. In this situation it is recommended to open the
cylinder valve, set the ow rate to 21-30cfh, close the cylinder valve and check after a
minimum of 15 minutes.
5. If there is a gas loss then check all connectors and clamps for leakage by brushing or spraying
with soapy water, bubbles will appear at the leakage point.
6. Tighten clamps or ttings to eliminate gas leakage.
8: Arc difcult to start or will not start DC welding
Possible Reason Suggested Remedy
Incorrect machine set up Check machine set up is correct
No gas, incorrect gas ow Check the gas is connected and cylinder valve open, check hoses, gas valve and torch
are not restricted. Set the gas ow between 10 - 15 l/min ow rate
Tungsten is contaminated Remove 10mm of contaminated tungsten and re grind the tungsten
Incorrect tungsten size and or tung-
sten being used
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
TIG WELDING TROUBLE SHOOTING - Continued
tt
Trouble Shooting