WELDTECH EZITIG 200AC/DC, Operating Instructions Manual

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EZITIG200 AC/DC Welding Machine
www.weldtech.net.nz
TIG Basic Welding
Guide
TIG Welding is a fusion procedure that uses an elec-
tric ARC created between an infusible tungsten elec-
trode and base material to be welded. For TIG weld-
ing 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, stainless steel, copper etc).
Electric Current
Inert Gas
Tungsten Electrode
Deposit
Melted Area
Penetration
Base Material
Protective Gas
Rod
Torch
TIG Welding
(Fig 15)
In TIG mode, welding is possible in all positions: flat,
angle, on the edge, vertical and overhead. Further-
more, with respect to other types of welding, the
welding 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.
Tig Electrode Selection
and Preparation
Electrode Polarity
Connect the TIG torch to the negative (-) torch termi-
nal and the work lead to the positive (+) work termi-
nal for direct current straight polarity. Direct current
straight polarity is the most widely used polarity for
DC TIG welding. It allows limited wear of the elec-
Tungsten Electrode
Tapered End
2.5 x Electrode Diameter
(Fig 16-1)
Preparing Tungsten for DC Electrode Negative
(DCEN) Welding
2.5 x Electrode Diameter
Grind end of tungsten on fine grit, hard abrasive
wheel before welding. Do not use wheel for other
jobs or tungsten can become contaminated causing
lower weld quality.
(Fig 16-2)
Stable ARC
Grinding
Wheel
Ideal Tungsten Preparation - Stable ARC
Diameter of the flat determines amperage capacity.
Flat
Straight Ground
trode since 70% of the heat is concentrated at the
work piece.