D/F MAC, Инструкция по эксплуатации, Страница: 18 / 22

Problems/Causes
SPATTER
Too fast or too slow wire feed for the arc voltage
Too long an arc
Damaged current tip
Inclination of welding gun too great
Faulty power source
Incorrect start
Incorrect pulse parameters
Uneven wire feed
Impurities on the base metal
Poor ground contact
Too long stick-out (short-arc welding)
Incorrect polarity
TROUBLESHOOTING: SPATTER
Possible Solutions
Set the wire feed rate and voltage in accordance with good weld-
ing practices as recommended by a qualified welding engineer.
Adjust the wire feed and voltage so that the arc is in accordance
with good welding practice for the joint to be welded. The dis-
tance from the current tip to the workpiece should be 15 times
the welding wire diameter. If the arc is too long there will be spat-
ter, usually in the direction of the weld.
If the current tip becomes worn the welding wire will not be in
constant contact with the tip and the arc will become unstable.
A current tip contaminated with spatter will cause uneven wire
feed resulting in further spatter.
The angle of the gas nozzle relative to the workpiece should be
between 45 and 90 degrees. If the angle is too small, the wire
runs parallel to the weld pool, resulting in spatter in the direction
of the welding.
Have the power source checked for faulty conditions such as
broken wires and faulty contacts.
A great deal of spatter occurs if the stick-out is too great and if
the welding gun is held too far from the workpiece when striking
the arc. Try to start with as short a stick-out as possible and with
the welding gun as close to the starting point as possible. If a
large ball end is formed on the end of the welding wire, remove
it by cutting the wire with sharp wire cutters. It is helpful if the
wire is cut to a point. Always remove the ball end before striking
an aluminum arc. Check the welding ground connection.
Check the user manual for your power supply or consult a quali-
fied welding engineer.
Uneven wire feed gives rise to heavy spatter. Find the cause of
the disturbance and correct the condition before proceeding.
Paint, mill scale, rust and other contamination on the base metal
form an insulating layer causing an unstable arc that results in
heavy spatter. Clean the surfaces to be welded.
Inspect ground cable for loose connections, fraying and cuts.
Correct any problem areas found and attach the ground cable
directly to the workpiece after having cleaned the contact sur-
face first. POOR GROUND CONTACT IS THE MOST COM -
MON CAUSE OF UNSTABLE MIG WELDING CONDITIONS.
The stick-out should be 15 times the diameter of the wire elec-
trode being used. With increasing stick-out, the current is re-
duced and the arc voltage rises, giving a longer unstable arc
and increased spatter.
Check for correct polarity. Follow the electrode manufacturer’s
recommendations.
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