39
TIG WELDING PROBLEMS
Before starng any welding acvity ensure that you have suitable eye protecon and
protecve clothing. Also take the necessary steps to protect any persons within the welding
area.
TIG welding defects and prevenon methods
Defect Possible cause Acon
Excessive tungsten use Set up for DCEP Change to DCEN
Insucient shield gas ow Check for gas restricon and correct ow
rates. Check for dras in the weld area.
Electrode size too small Select correct size
Electrode contaminaon during
cooling me
Extend post ow gas me
Porosity/weld contaminaon Loose torch or hose ng Check and ghten all ngs
Inadequate shield gas ow Adjust ow rate - normally 8-12L/m
Incorrect shield gas Use correct shield gas
Gas hose damaged Check and repair any damaged hoses
Base material contaminated Clean material properly
Incorrect ller material Check correct ller wire for grade of use
No operaon when torch
switch is operated
Torch switch or cable faulty Check the torch switch connuity and
repair or replace as required
ON/OFF switch turned o Check posion of ON/OFF switch
Mains fuses blown Check fuses and replace as required
Fault inside the machine Call for a repair technician
Low output current Loose or defecve work clamp Tighten/replace clamp
Loose cable plug Check and ghten all plugs
Power source faulty Call a repair technician
Will not strike an arc Weld/power cable open circuit Check all cables and connecons for
connuity, especially the torch cables
No shield gas owing Check cylinder contents, regulator and
valves, also check the power source
Unstable arc when welding in
DC
Tungsten contaminated Break o contaminated end and regrind
the tungsten
Arc length incorrect Arc length should be between 3-6mm
Material contaminated Clean all base and ller material
Electrode connected to the wrong
polarity
Reconnect to correct polarity
Arc is dicult to start Incorrect tungsten type Check and t correct tungsten
Incorrect shield gas Use argon shield gas
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