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Stick welding basics
By Mike Brace
Welding Engineer, Miller Electric Mfg. Co.
Now that you're ready to weld, remember CLAMS: Current
setting, Length of arc, Angle of travel, Manipulation,
and Speed of travel. Bringing all these points together
in one moment of welding may seem like a lot to think about,
but it becomes second nature with practice. And don't get
discouraged! Stick welding got its name not because the electrode
looks like a stick, but because everybody sticks the rod to
the workpiece when learning how to weld.
Current setting
The correct current (or amperage) setting primarily depends
on the diameter and type of electrode selected. For example,
a 1/8-inch 6010 rod runs well from 75 to 125 amps, while a
5/32-inch 7018 rod welds at currents up to 220 amps. The side
of the electrode box usually indicates operating ranges. Select
an amperage based on the material's thickness, welding position
(about 15% less heat for overhead work compared to a flat
weld) and observation of the finished weld. Most new welding
machines have a permanent label that recommends amperage settings
for a variety of electrodes and material thicknesses.
Length of arc
The correct arc length varies with each electrode and application.
As a good starting point, arc length should not exceed the
diameter of the metal portion (core) of the electrode. Holding
the electrode too closely decreases welding voltage. This
creates an erratic arc that may extinguish itself or cause
the rod to freeze, as well as produces a weld bead with a
high crown. Excessively long arcs (too much voltage) produce
spatter, low deposition rates, undercuts, and maybe porosity.
Many beginners weld with too long of an arc, so they produce
rough beads with lots of spatter. A little practice will show
you that a tight, controlled arc length improves bead appearance,
creates a narrower bead, and minimizes spatter.
Angle of travel
Stick welding in the flat, horizontal, and overhead position
uses a drag (or backhand) welding technique. Hold the rod
perpendicular to the joint and tilt the top of the electrode
in the direction of travel approximately 5° to 15°.
For welding vertical up, use a push (or forehand) technique,
and tilt the top of the rod 15° away from the direction
of travel.
Manipulation
Each welder manipulates or weaves the electrode in a unique
style. Develop your own style by observing others, practicing,
and creating a method that produces good results for you.
Note that on material 1/4 inch and thinner, weaving the rod
typically creates a bead that is wider than necessary. In
many instances, plain, straight-ahead travel works fine.
To create a wider bead on thicker material, manipulate the
electrode from side to side creating a continuous series of
partially overlapping circles, or in a "Z" semi-circle
or stutter-step pattern. Limit side-to-side motion to 2 1/2
times the diameter of the electrode core. To cover a wider
area, make multiple passes, or stringer beads.
When welding vertical up, focus on welding the sides of
the joint and the middle will take care of itself. Pause slightly
at the side to allow the far side of the bead to cool, the
weld puddle to catch up, and to ensure solid "tie-in"
to the sidewall. If your weld looks like fish scales, you
moved forward too quickly and didnŐt hold long enough on the
sides.
Speed of travel
The proper travel speed produces a weld bead with the desired
contour (or crown), width, and appearance. Adjust travel speed
so that the arc stays within the leading one-third of the
weld pool. Slow travel speeds produce a wide, convex bead
with shallow penetration. Excessively high travel speeds also
decrease penetration, create a narrower and/or highly crowned
bead, and possibly undercuts. A few last words of advice.
Always remember that you need a good view of the weld puddle.
Otherwise, you can't ensure you're welding in the joint, keeping
the arc on the leading edge of the puddle, and using the right
amount of heat (you can actually see a puddle with too much
heat roll out of the joint). For the best view, keep your
head off to the side and out of the smoke so you can easily
see the puddle.
Also remember that you learn through mistakes. There's no
shame in grinding out bad welds. In fact, professional welders
create perfect welds by recognizing imperfections, grinding
them out, and rewelding.
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