Northern Industrial Welding
10
Operating Instructions and Parts Manual
ST80i
A good arc is accompanied by a crisp,
cracking sound. The sound is similar
to that made by eggs frying. To lay a
weld bead, only 2 movements are
required; downward and in the
direction the wel
d is to be
laid, as in
following figure:
2.3 Types of weld bead
The following paragraphs discuss the
most commonly used arc welding
beads.
The stringer bead
Formed by
traveling with the electrode in a
straight line while keeping it centered
over the weld joint.
The weave bead
Used when you
want to deposit metal over a wider
space than would be possible with a
stringer bead. It is made by weaving
from side to side while moving with
the electrode. It is best to hesitate
momentarily at each side before
weaving back the other way to
improve penetration.
2.4 Welding position
Flat position
is the easiest of the
welding positions and is most
commonly used. It is best if you can
weld in the flat position if at all
possible as good results are easier to
achieve.
The horizontal position
is
performed very much the same as
the flat weld except that the angle is
different such that the electrode, and
therefore the arc force, is directed
more toward the metal above the
weld joint. This more direct angle
helps prevent the weld puddle from
running downward while still allowing
slow enough travel speed to achieve
good penetration. A good starting
point for your electrode angle is about
30 degrees DOWN from being
perpendicular to the work piece.
2.5 Judge a good weld bead
When the trick of establishing and
holding an arc has been learned, the
next step is learning how to run a
good bead. The first attempts in
practice will probably fall short of
acceptable weld beads. Too long of
an arc will be held or the travel speed
will vary from slow to fast (see
following)
Summary of Contents for ST 80 i
Page 1: ...67 L 23 5 7 1 0 18...
