Basic tig operation, Tigweld® 250 ex, Tig operation and principles – Longevity TIGWELD 250 EX User Manual
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TIGWELD® 250 EX
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Basic TIG Operation
(Tungsten Inert Gas - Gas Tungsten Arc Welding - GTAW)
TIG Operation and Principles:
Shielding Gas: Use 100% Argon at 15-25 (cubic feet per hour). Set the gas flow using the
regulator on the gas bottle. Use higher flow when extending the tungsten electrode to reach into
corners or gaps.
Tungsten Electrode: We recommend 2% Thoriated tungsten (red) for TIG welding with our DC
TIG welders. Use smaller diameter electrodes for thinner metal (low amperage), thicker
electrodes for thicker metals that require more amperage. For the right tungsten electrode, please
refer to earlier in this manua
Filler Rod Selection: Depending upon the metal to be welded, filler rod selection is critical.
Consult with your local welding supplier for the optimum filler rod to properly complete the
weld. In certain applications, TIG welding can be performed without the use of a filler rod. Use
free welding for
to gather advice or go
Pre-TIG Welding
As you get to know the above information of basic TIG welding applications, there are a couple
of basic steps that need to be taken. The tungsten must be sharpened and shaped before initiating
an arc. With inverter TIG welding machines, tungsten sharpness is important. Your weld’s
outcome will be partially determined by the shape of your tungsten. Sharpening an electrode
consistently will cause an unstable, wandering arc, making it more difficult to control the weld
puddle. Carefully rotate the tungsten as it is being ground to prevent a flat spot or a hollow
ground point. Also note that tapering the tungsten to 2.5 times of its diameter is generally
recommended for most DC welding applications. For high amperage DC welding, do not over
sharpen the point, but leave a slight truncation on the end of the tungsten. This prevents the
tungsten tip from breaking away and falling into the weld. It is also normal for a slight dome to
form on the tungsten in DC mode. However, if the arc becomes erratic or the arc is difficult to
start, regrinding the tungsten will be necessary. If the tungsten is accidentally dipped into the
weld puddle, regrinding the tungsten will be necessary to eliminate contamination, particularly
on aluminum. Grind tungsten’s only on a dedicated stone, free of contamination from other
metals.