Würth MIG 180-5S Mode D'emploi Original page 32

weld puddle and to direct the force of the arc.
(see fig. F (b) on page 8)
4. Distance from the workpiece
If the nozzle is held off the work piece, the distance
between the nozzle and the workpiece should be
kept constant and should not exceed 6 mm or the
arc may begin sputtering, signaling a loss in welding
performance.
5. Tuning in the wire speed
This is one of the most important parts of MIG
welder operation and must be done before starting
each welding job or whenever any of the following
variables are changed: heat setting, wire diameter,
or wire type.
WARNING!
Exposure to a welding arc is extremely
harmful to your eyes and skin!
Prolonged exposure to the welding arc can cause
blindness and burns. Never strike an arc or begin
welding until you are adequately protected. Wear
flameproof welding gloves, a heavy long sleeved
shirt, trousers with no cuffs, high topped shoes, and
an approved welding helmet.
5.1. Connect the Ground Clamp to a scrap piece of
the same type of material which you will be welding.
It should be equal to or greater than the thickness of
the actual workpiece, and free of oil, paint, rust, etc.
5.2. Select the heat setting. Refer to set up chart.
5.3. Hold the torch in one hand, allowing the noz-
zle to rest on the edge of the workpiece farthest
away from you, and at an angle similar to that which
will be used when welding. (See HOLDING THE
TORCH if you are uncertain of the angle at which
you will be welding).
5.4. With your free hand, turn the Wire Speed Dial
to maximum and continue to holding the knob.
5.5. Lower your welding helmet and pull the trigger
on the torch to start an arc, then begin to drag the
torch towards you, while simultaneously turning the
Wire Speed Dial counter-clockwise.
5.6. LISTEN! While decreasing wire speed, the sound
that the arc produces will change from a sputtering
to a high-pitched buzzing sound and then will begin
sputtering again if you decrease the wire speed too
much. The position of the wire speed adjustment knob
where the high-pitched buzzing sound is achieved
represents the correct setting. You can use the wire
speed control to slightly increase or decrease the heat
and penetration for a given heat setting by selecting
higher or lower wire speed settings. Repeat this tune-in
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procedure if you select a new heat setting, a different
wire diameter, or a different type of welding wire.
6. Welding Techniques
Electric shock can kill!
To prevent ELECTRIC SHOCK, do not perform any
welding while standing, kneeling, or lying directly on
the grounded work.
6.1 Moving the torch
Torch travel refers to the movement of the torch along
the weld joint and consists of two action elements:
Direction and Speed. A solid weld bead requires
that the welding torch be moved steadily and at the
right speed along the weld joint. Moving the torch
too fast, too slow, or erratically will prevent proper
fusion or create a lumpy, uneven bead.
Travel direction is the direction the torch moved
along the weld joint in relation to the weld puddle.
The torch is either PUSHED into the weld puddle (see
fig. G (a) on page 9) or PULLED away from the weld
puddle (see fig. G (b) on page 9). For most weld-
ing jobs you will pull the torch along the weld joint to
take advantage of the greater weld puddle visibility.
Travel speed is the rate at which the torch is being
pushed or pulled along the weld joint. For a fixed
heat setting, the faster the travel speed, the lower the
penetration, and lower and narrower the finished
weld bead. Likewise, the slower the travel speed, the
deeper the penetration and the higher and wider the
finished weld bead.
6.2 Types of weld beads
As you become more familiar with your new welder
and better at laying some simple weld beads, you
can begin to try some different weld bead types.
The STRINGER BEAD is formed when torch is trave-
ling in a straight line while keeping the wire and nozzle
centered over the weld joint.
(see fig. H (a) on page 9)
The WEAVE BEAD is used when you want to deposit
metal over a wider space which wouldn't be possible
using a stringer bead (without transfer oscillation).
It is made by weaving electrode from side to side
with slight hesitation at the end of each oscillation
while moving it longitudinally. That is the best way to