Lincoln Electric IM366-B Manuale Utente
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17
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Practice.
The best way of getting practice in the four skills that
enable you to maintain:
enable you to maintain:
1. Correct welding position
2. Correct way to strike an arc
3. Correct electrical stickout
4. Correct welding speed
2. Correct way to strike an arc
3. Correct electrical stickout
4. Correct welding speed
is to spend a little more time on the following exercise.
Use the following:
Mild Steel
16 gauge or 1/16 inch (1.6 mm)
Electrode
.035" (0.9 mm) NR-211-MP
Innershield wire
Voltage setting “V”
E
Wire feed speed olo
2
1. Learn to strike an arc by positioning the gun over
the joint and touching the wire to the work.
2. Position faceshield to protect face and eyes.
3. Depress gun trigger, hold gun so contact tip to work
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.
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 for the ridge where the metal solidifies.
start moving. Look at the molten puddle constantly,
and look for 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 better than the
first weld. By constantly checking on your mistakes
and your progress, welding will soon be a matter of
routine.
gives you practice in running straight welds, and
also gives you an easy way to check your progress.
The 10th weld will look considerably better than the
first weld. By constantly checking on your mistakes
and your progress, welding will soon be a matter of
routine.
COMMON METALS
Most metals found around the farm, small shop or
home are low carbon steel, sometimes referred to as
mild steel. Typical items made with this type of steel
include most sheet metal, plate, pipe and rolled
shapes such as channels and angle irons. This type of
home are low carbon steel, sometimes referred to as
mild steel. Typical items made with this type of steel
include most sheet metal, plate, pipe and rolled
shapes such as channels and angle irons. This type of
The Correct Electrical Stickout
The electrical stickout (ESO) is the distance from the
end of the contact tip to the end of the wire.
end of the contact tip to the end of the wire.
Once the arc has been established, maintaining the
correct ESO becomes extremely important. The ESO
should be approximately 3/8 to 1/2 inch (10 to 12 mm)
long.
correct ESO becomes extremely important. The ESO
should be approximately 3/8 to 1/2 inch (10 to 12 mm)
long.
The easiest way to tell whether the ESO is the correct
length is by listening to its sound. The correct ESO
has a distinctive “crackling” sound, very much like
eggs frying in a pan. A long ESO has a hollow, blow-
ing or hissing sound. If the ESO is too short, you may
stick the contact tip or nozzle to the weld puddle
and/or fuse the wire to the contact tip.
length is by listening to its sound. The correct ESO
has a distinctive “crackling” sound, very much like
eggs frying in a pan. A long ESO has a hollow, blow-
ing or hissing sound. If the ESO is too short, you may
stick the contact tip or nozzle to the weld puddle
and/or fuse the wire to the contact tip.
The Correct Welding Speed
The important thing to watch while welding is the pud-
dle of molten metal right behind the arc. Do not watch
the arc itself. It is the appearance of the puddle and
the ridge where the molten puddle solidifies that indi-
cates correct welding speed. The ridge should be
approximately 3/8" (10 mm) behind the wire electrode.
dle of molten metal right behind the arc. Do not watch
the arc itself. It is the appearance of the puddle and
the ridge where the molten puddle solidifies that indi-
cates correct welding speed. The ridge should be
approximately 3/8" (10 mm) behind the wire electrode.
Most beginners tend to weld too fast, resulting in a
thin, uneven, “wormy” looking bead. They are not
watching the molten metal.
thin, uneven, “wormy” looking bead. They are not
watching the molten metal.
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.
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.
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
burnthrough. One way to eliminate these problems
is to use the backstepping method.
burnthrough. One way to eliminate these problems
is to use the backstepping method.
Contact tip
Wire electrode
3/8 - 1/2” Electrical Stickout
Ridge where puddle
solidifies
solidifies
Molten puddle
Contact
tip
tip
3/8-1/2”ESO
(10-12mm)
Gun angle
First weld from A to B; then
from C to A; then from D to C;
then from E to D, and so on.
from C to A; then from D to C;
then from E to D, and so on.
BACKSTEPPING
2-3”
(50-75mm)
B
A
C
D
E