Tig Basic Welding Guide - Weldclass FORCE 200MST MK2 Operating Instructions Manual

TIG Basic
Welding Guide
TIG Welding is a fusion procedure that uses an
electric ARC created between an infusible tungsten
electrode and 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, stainless steel, copper etc).
TIG Welding
(Fig 15)
Torch
Rod
Protective Gas
In TIG mode, welding is possible in all positions:
flat, angle, on the edge, vertical and overhead.
Furthermore, 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
terminal and the work lead to the positive (+) work
terminal 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 electrode since 70% of the heat is
concentrated at the work piece.
24
Electric Current
Inert Gas
Tungsten Electrode
Deposit
Melted Area
Penetration
Base Material
Preparing Tungsten for DC Electrode Negative
(DCEN) Welding
(Fig 16-1) Tungsten Electrode
2.5 x Electrode Diameter
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)
Straight Ground
Ideal Tungsten Preparation - Stable ARC
Diameter of the flat determines amperage capacity.
Tapered End
Stable ARC
Flat
Grinding
Wheel