TEC.LA Ergus WIG 160 CDI, User Manual, Page: 15 / 36

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1. TIG welding
TIG welding is a fusion procedure that uses as a source of heat an electric arc created between an infusible
tungsten electrode and the base material to be welded. For TIG welding an inert gas must be used (ARGON) which
protects the welding bead. If filling material is used, it is made up of rods suitable to the material to be welded
(steel, steinless steel, copper, etc).
In TIG mode, welding it is possible in all positions: flat, angle, on the edge, vertical and overhead. Furthermore,
with respect to other types of welding, the welded joint has greater mechanical resistance, greater corrosion
resistance and limited heating in the welded area which limits distortion. Welding can be done even without weld
material, guaranteeing a smooth, shiny weld with no impurities or slag.
Preparation of material
Welding results also depend on the cleanliness of the piece before it is welded. Edges must always be properly
shaped before cleaning operations. The most suitable ones are “V” or “X”.
Preparation of joints must be done so that there is good penetration.
Once these are ready, they must be cleaned, de-greased with solvents, they can be brushed or ground with
attention to chips removal.
Pure ARGON gas should be used. If other blends are used, oxidation may occur.
Electrode selection and preparation
The electrode must withstand as much current as possible without melting, because melted tungsten would
contaminate the welded metal. Tungsten may form hard inclusions that compromise the resistance of the weld.
When welding in alternating current, where polarity changes continually from positive to negative, the current must
be strong enough to slightly melt the electrode tip.
WELDING CURRENT AND RELATIVE ELECTRODE DIAMETER
electrode (mm)
Direct current (A)
Negative pole
1.0 (1/32”)
1.6 (1/16”)
2.4 (3/32”)
3.2 (1/8”)
10-70
60-150
100-250
200-400
ELECTRIC CURRENT
INERT GAS
TUNGSTEN ELECTRODE
DEPOSIT
PENETRATION
MELTED AREA
BASE MATERIAL PROTECTIVE GAS
TORCH
ROD