AUTO ARC 120 - WELD BEAD CHARACTERISTICS AND TROUBLESHOOTING

7-2.
Welding
Troubleshooting
Table
7-1.
Porosity
Porosity

small
cavities
or
holes
resulting
from
gas
pockets
in
weld
metal.
S-0635
Possible
Causes
Corrective
Actions
Inadequate
shielding
gas
coverage.
.
Check
for
proper
gas
flow
rate.
Remove
spatter
from
gun
nozzle.
Check
gas
hoses for leaks.
Eliminate
drafts
near
welding
arc.
Place nozzle
1/4
to
1/2
in
(6-13 mm)
from
workpiece.
Hold
gun
near
bead
at
end
of
weld until molten metal
solidifies.
Wrong
gas.
Use
welding grade
shielding
gas;
change
to
different
gas.
Dirty welding
wire. Use
clean,
dry welding
wire.
Eliminate
pick
up
of
oil
or
lubricant
on
welding
wire
from feeder
or
liner.
Workpiece
dirty.
Remove all
grease,
oil,
moisture,
rust,
paint,
coatings,
and
dirt from
work surface
before
welding.
Use
a
more
highly deoxidizing welding
wire
(contact
supplier).
Welding
wire extends
too
far
out
of
nozzle.
Be
sure
welding
wire
extends
not
more
than
1/2
in
(13 mm)
beyond
nozzle.
POOR
WELD BEAD
I
Large
Spatter
Deposits
2
Rough,
uneven
bead
3
Slight
Crater
During
Welding
4
Bad
Overlap
5
Poor
Penetration
:.~
5
GOOD
WELD
BEAD
S.0053-A
1
Fine
Spatter
2
Uniform
Bead
3 Moderate
Crater
During
Welding
Weld
a
new
bead
or
layer
for
each
1/8
in
(3.2
mm)
thickness
in
metals
being
welded.
4
No
Overlap
5
Good Penetration
Into
Base
Metal
Figure
7-4.
Weld
Bead
Characteristics
S-0052-B
OM-151 015
Page
18