Lincoln Electric SP 170-I, Operator'S Manual

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B-13
SP 170-I
B-13
LEARNING TO WELD
Mild Steel 16 gauge or 1/16 inch
(1.6 mm)
Electrode 0.035" (0.9 mm)
NR-211-MP
Innershield Wire
Voltage Setting “ V ” A
Wire Feed Speed “ o|o ” 1.5
For the SP 170-I, use the following:
Helpful Hints
1. For general welding, it is not necessary to weave
the arc, neither forward or backward nor sideways.
Weld along at a steady pace. You will find it easier.
2. When welding on thin plate, you will find that you
will have to increase the welding speed, whereas
when welding on heavy plate, it is necessary to go
more slowly in order to get good penetration.
3. When welding sheet metal 16 gauge (1.5 mm) and
lighter, heat buildup may cause part warpage and
burn through. One way to eliminate these problems
is to use the back-stepping method illustrated in
Figure B.21.
FIGURE B.21
Practice
The best way of getting practice in the four skills that
enable you to maintain:
1. Correct welding position
2. Correct way to strike an arc
3. Correct electrical stickout
4. Correct welding speed
is to perform the following exercise.
Refer to Figure B.22.
1. Learn to strike an arc by positioning the gun over
the joint and touching the wire to the work.
2. Position face shield to protect face and eyes.
3. Depress gun trigger, hold gun so contact tip to
work distance is about 3/8 to 1/2 inch (10 to 12
mm) and the gun is at proper angle.
4. After you strike the arc, practice the correct electri-
cal stickout. Learn to distinguish it by its sound.
5. When you are sure that you can hold the correct
electrical stickout, with a smooth “ crackling ” arc
start moving. Look at the molten puddle constantly,
and look at the
“ ridge ” where the metal solidifies.
6. Run beads on a flat plate. Run them parallel to the
top edge (the edge farthest away from you). This
gives you practice in running straight welds, and
also gives you an easy way to check your
progress. The 10th weld will look considerably bet-
ter than the first weld. By constantly checking on
your mistakes and your progress, welding will soon
be a matter of routine.
First weld from A to B; then from C to A; then
from D to C; then from E to D, and so on.
B A C D E
Back-Stepping
FIGURE B.22
Contact
Tip
Gun Angle
ESO