User manual

Northern Industrial Welding
8
Operating Instructions and Parts Manual
ST80i
4. Ground clamp connection
Clear any dirt, rust, scale, oil or paint
on the ground clamp. Make certain
you have a good solid ground
connection. A poor connection at the
ground clamp will waste power and
heat. Make sure the ground clamp
touches the metal.
5. Electrode
The welding electrode is a rod coated
with a layer of flux. When welding,
electrical current flows between the
electrode (rod) and the grounded
metal work piece. The intense heat of
the arc between the rod and the
grounded metal melts the electrode
and the flux. The most popular
electrodes are:
-E6011 60,000 PSI tensile strength
deep penetrating applications.
-E6013 60,000 PSI tensile strength
used for poor fit up applications
-E7014 70,000 PSI tensile strength
used for high deposition and fast
travel speeds with light penetration
-E7018 70,000 PSI tensile strength,
Used for out of position and tacking.
6. Selecting the proper electrode
There is no golden rule that
determine the exact rod or heat
setting required for every situation.
The type and thickness of metal and
the position of the work piece
determine the electrode type and the
amount of heat needed in the welding
process. Heavier and thicker metals
required more amperage. It is best to
practice your welds on scrap metal
which matches the metal you intend
to work with to determine correct heat
setting and electrode choice. See
following some helpful trouble
shooting tips to determine if you are
using a correct electrode
1. When proper rod is used:
a. The bead will lay smoothly over
the work without ragged edges
b. The base metal puddle will be as
deep as the bead that rises
above it
c. The welding operation will make
a crackling sound similar to the
sound of eggs frying
2. When a rod too small is used：
a. The bead will be high and
irregular
b. The arc will be difficult to
maintain
3. When the rod is too large：
a. The arc will burn through light
metals
b. The bead will undercut the work