OPERATION
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The size of the electrode generally
depends on the thickness of the section
being welded, and the thicker the section
the larger the electrode required. The
maximum size of electrodes that may be
used for various thicknesses based on a
general purpose type 6013 electrode.
Welding Current (Amperage)
Correct current selection for a particular
job is an important factor in arc welding.
With the current set too low, difficulty is
experienced in striking and maintaining a
stable arc. The electrode tends to stick to
the work, penetration is poor and beads
with a distinct rounded profile will be
deposited. Too high current is accompanied
by overheating of the electrode resulting undercut and burning through of the base metal
and producing excessive spatter. Normal current for a particular job may be considered
as the maximum, which can be used without burning through the work, over-heating the
electrode or producing a rough spattered surface. The table shows current ranges
generally recommended for a general purpose type 6013 electrode.
Arc Length
To strike the arc, the electrode should be gently scraped on the work until the arc is
established. There is a simple rule for the proper arc length; it should be the shortest arc
that gives a good surface to the weld. An arc too long reduces penetration, produces
spatter and gives a rough surface finish to the weld. An excessively short arc will cause
sticking of the electrode and result in poor quality welds. General rule of thumb for down
hand welding is to have an arc length no greater than the diameter of the core wire.
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