28
Setup Guide and component Identification
Section 2
BASIC MIG OPERATION
Characteristics:
Concave weld, poor filling, possi-
ble undercutting resulting in weak weld.
Possible Causes:
Voltage too high, not enough
wire speed, too short of wire stick out, wrong gun
angle.
Remedy:
Decrease voltage, use push motion, in-
crease wire speed.
Characteristics:
Small Convex weld possibly
with
bulging sides/cold lap and/or an inconsistent arc.
Possible Causes:
Not enough Voltage or Amper-
age. If weld is ropy and thin without bulging at the
toes, travel speed is too fast or using a pull tech-
nique.
Remedy:
Increase voltage and amperage, slow
down to fill joint more. Use push technique.
Characteristics:
Large convex weld with bulging at
toes, weld legs exceed thickness of the metal being
welded.
Possible Causes:
Not enough voltage, too much
wire speed, overfilling due to too slow of forward
travel speed, and/or poor weaving technique.
Remedy:
Increase voltage, increase forward travel
speed, reduce weaving width.
Proper Weld Characteristics:
Weld is slightly con-
vex, weld legs (vertical and horizontal width of
weld) are equal in length and match the thickness of
the metal being welded. No traces of undercutting,
Proper tie in of the weld at the toes with no cold
lap. Weld is not overfilled or under
-
filled with no
significant amounts of spatter, soot or contaminates
around weld. Weld is not oxidized and is bright.
NO
NO
NO
YES
