24
Note: Due to inherent variances in ux-
cored welding wire, it may be necessary to
use a contact tip one size larger than your
ux core wire if wire jams occur.
1. If the wire burns back into the tip, remove
the tip from the gun and clean the hole
running through it with an oxygen-acety-
lene torch tip cleaner or tip drill.
2. Over time, the hole in the contact tip will
become worn by the wire passing
through it. The more worn this hole
becomes, the less ecient is the transfer
of welding current to the wire and even-
tually arc breakage and dicult arc
starting will result. Replace contact tips
when signs of wear become apparent.
MAINTAINING THE NOZZLE
The nozzle directs the shielding gas to the
weld puddle, determines the size of the
shielding area, and prevents the electrically
hot contact tip from contacting the work piece.
CAUTION
KEEP THE NOZZLE CLEAN! During the
welding process, spatter and slag will build
up inside the nozzle and must be cleaned
out periodically. Failure to clean and/or
replace the nozzle in a timely
fashion WILL
CAUSE DAMAGE TO THE FRONT-END OF
THE GUN ASSEMBLY.
For best results, coat the inside of a new, or
freshly cleaned nozzle with anti stick spray
or gel.
1. Stop welding and clean any accumulated
slag or spatter from the nozzle every 5 to
10 minutes of welding time.
2. When welding overhead, if any molten
metal drips from the weld puddle and
falls into the nozzle, STOP WELDING
IMMEDIATELY and clean the nozzle.
3. If the slag cannot be thoroughly cleaned
from the nozzle, REPLACE THE NOZZLE!
Failure to keep the nozzle adequately
cleaned can result in the following problems:
A SHORTED nozzle results when spatter
buildup bridges the insulation in the nozzle,
allowing welding current to ow through it
as well as the contact tip. When shorted, a
nozzle will steal welding current from the
wire whenever it contacts the grounded
work piece. This causes erratic welds and
reduced penetration. In addition, a shorted
nozzle overheats the end of the gun, which
can DAMAGE the front-end of the gun.
A RESTRICTED nozzle is created when
enough slag builds up in the nozzle to aec
t
the direction, concentration, and/or rate of
the shielding gas ow. This problem can cause
porous, brittle welds and reduce penetration.
TESTING FOR A SHORTED NOZZLE
Arcing between the nozzle and the work
piece ALWAYS means the nozzle is shorted,
but this can be hard to detect through the
lens of a welding helmet. The following test-
ing method is another way to tell if a nozzle
is shorted.
With the welder unplugged from the ac
power source, touch the probes of an ohm-
meter or continuity tester to the end of the
contact tip and the outside of the nozzle. If
there is any continuity at all, the nozzle IS
shorted. Clean or replace as needed.
REPLACE A GUN LINER
When installing a new gun liner, care must be
taken not to kink or otherwise damage the
gun liner. See Figure 22 for the drive assem-
bly and Figure 23 for the gun assembly.
1. Turn OFF welder POWER SWITCH and
unplug welder from power supply.
2. Open the welder side panel.
3. Loosen the tension arm and lift it up o
the drive roller.
4. Turn the wire spool counter-clockwise (be
sure to hold onto the wire itself while turn-
ing the spool or the wire will unspool itself
when it becomes free of the gun liner),
and remove wire from gun assembly.
5. Lay gun cable and gun handle straight
out in front of unit.
6. Remove gun liner holding clamp by
removing the three screws.
7. Take gun handle halves apart by remov-
ing ve phillips head screws.
8. Remove gas hose from fast coupler t-
ting on Gas Valve. Depress lip on fast
coupler tting back towards tting and
pull gas hose out.
9. Remove Fast Coupler Fitting from Gas
Valve using a 9 millimeter wrench.
10. Firmly hold the brass tting on the end
