REHM TIGER 180 AC/DC ULTRA, Operating Instructions Manual

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Operation
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REHM supply its torches with WC 20 (grey) tungsten electrodes as standard.
The most frequently used electrode diameter and their capacities can be found in
the relevant specialist publications. Please consider that the values given are
mainly established by machines, which do not have by far the balance range of
REHM TIG units. All guidelines state that a specific electrode is exposed to a
current that is too high if it drips or takes on a brush-like appearance. You have
the choice between lower current or, with AC operation, using a larger minus
portion in the balance setting.
When welding with DC the electrode is ground to a point.
With the REHM TIG welding system it is also possible to work in the AC range
with balance adjustments in the negative range using a pointed electrode. This
offers the advantage that the arc is even more concentrated and effective. In
most cases this increases the welding speed.
When grinding the electrode take care that the direction of grinding is in the
longitudinal direction of the electrode. For this task use a hazard-reducing
grinding apparatus with extraction.
In TIG welding the protective gas is mainly argon. Helium, argon-helium mixture,
or argon-hydrogen mixture is used for special applications. Igniting the arc
becomes more difficult and the thermal input increases with an increasing portion
of helium. The quantity of protective gas required depends on the electrode
diameter, size of the gas nozzle, welding current strength and the movement of
air depending on the working place. With a workpiece of 4 mm thickness using
argon as a protective gas an example reference value for aluminium is
approximately 8 litres/minute and for steel and chrome-nickel steel approximately
6 litres/minute. If helium is used the required quantity is significantly higher.
The standard length of the TIG welding torch is 4m and 8m. However, longer
torches can be used with these machines. The matching tungsten electrode,
clamping sleeve and gas nozzle must be selected depending on the welding task
and the current strength. When using a torch with two triggers it is possible to
switch the current between the two adjustable values during welding.
Welding additives are added in rod form when welding manually. The correct
tungsten must be selected depending on the base material. However, excellent
results can be achieved if the weld pool of two parts is allowed to run together, as
in the case of corner seams.
Protective gases
TIG
welding torch
Welding
with and without
additional
materials