Operation; Getting To Know Your New Welder; Setting The Controls - Sears Craftsman 934.20105 Owner's Manual

OPERATION Page 19
OPERATION
GETTING TO KNOW YOUR NEW
WELDER
Whether you have welded before or not, it is impor-
tant that you become familiar with your new
welder, its controls, and the results achieved at
different settings. We strongly recommend that
you practice with your new welder on scrap metal
trying different heat settings, base metal thick-
nesses, and welding positions for each type and
size of wire that you will be using. By doing this
you will gain a feel for how changes in these
welding variables affect the weld.
Of course, if you have not MIG welded before, you
will need to develop welding skills and techniques
as well. The self-taught welder learns through a
process of trial and error. The best way to teach
yourself how to weld is with short periods of prac-
tice at regular intervals.
DO NOT ATTEMPT TO WELD on any valuable
equipment until you have made practice welds on
scrap metal that can be discarded. The scrap
metal should be of the same type and thickness as
that of the item to be welded. Only after you are
satisfied that your practice welds are of good
strength and appearance, should you attempt your
actual welding job.
SETTING THE CONTROLS
1. The POWER SWITCH has three settings: LOW,
OFF, and HIGH. When in the OFF position,
power is disconnected from all welder functions.
The LOW position is selected for welding steel
thicknesses of 16 gauge or thinner. The HIGH
position is selected for steel thicker than 16
gauge. The variables that affect the heat selec-
tor setting are wire type and size, base metal
type and thickness, and desired penetration.
2. The WIRE SPEED CONTROL is variable from
SLOW to FAST. To achieve successful welding
results, it is important that the wire be fed at the
same rate it is being melted off into the weld
puddle; if too fast the wire will tend to push the
gun away from the work piece and if too slow,
the wire will bum back into, and may damage
the contact tip. In either case, an extremely
poor weld will result.
"TUNING IN" THE WIRE SPEED 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.
a. Set up and ground a scrap piece of the same
type of metal that you will be welding, it
should be equal to or greater than the thick-
ness of the actual work piece and free of
paint, oil, rust, etc.
b. Select a heat setting.
c. Hold the gun in one hand atlowing the nozzle
to rest on the edge of the work piece farthest
away from you and at an angle similar to that
which will be used when actually welding.
d. With your free hand, turn the WIRE SPEED
control to maximum and continue to hold
onto the knob.
ARC RAYS CAN INJURE EYES AND BURN
SKINI To reduce risk of injury from arc rays, never
strike a welding arc until you and all bystanders in
the welding area have welding helmets or shields
in place and are wearing the recommended pro-
tective clothing. DO NOT CONTINUE unless you
have read, understand, and intend to follow the
entire SAFETY INSTRUCTIONS section of this
manual.
e,
Lower your welding helmet and pull the trig-
ger on the gun to start an arc, then begin to
drag the gun toward you while turning down
on the WIRE SPEED control knob at the
same time.
LISTEN! As you decrease the wire speed,
the sound that the arc makes will change
from a sputtering to a smooth, high-pitched
buzzing sound and then will begin sputtering
again if you decrease the wire speed too far.
Selecting the best wire speed setting is much the
same as "tuning in" a radio: continue decreasing
the wire speed until the arc noise passes the best-
sounding, high-pitched buzz and begins to sputter
again, then turn the WIRE SPEED control the
opposite direction until you come back to the best
sounding arc noise. The welder is now "tuned in"
and welding can begin.