7
WG3013
Welding Guidelines
General
This line of welding machines can
utilize the Flux Cored Arc Welding
(Gasless) process or the Gas Metal Arc
Welding (MIG) process. The weld must
be protected (shielded) from
contaminates in the air while it is
molten. The gasless process uses a
tubular wire with a flux material inside.
The flux creates a shielding gas when
melted. The MIG process uses inert gas
to shield the weld while molten.
When current is produced by a
transformer (welding machine) and
flows through the circuit to the weld
wire, an arc is formed between the end
of the weld wire and the work piece.
This arc melts the wire and the work
piece. The melted metal of the weld
wire flows into the molten crater and
forms a bond with the work piece as
shown (Figure 9).
Arc Welding Basics
Five basic techniques affect weld
quality. These are: wire selection, heat
setting, weld angle, wire speed, and
travel speed. An understanding of
these techniques is necessary for
effective welds.
HEAT SETTING
The correct heat involves the adjust-
ment of the welding machine to the
required setting. Heat or voltage is
regulated by a switch on the welder.
The heat setting used depends on the
size (diameter) and type of wire,
position of the weld, and the thickness
of the work piece. Consult specif-
ications listed on the welder. It is
suggested that the welder practice with
scrap metal to adjust settings and
compare welds with Figure 11.
WIRE TYPE AND SIZE
The correct choice of wire type involves
a variety of factors, such as welding
position, work piece material type,
thickness and condition of surface to be
welded. The American Welding Society,
AWS, has set up certain requirements
for each type of wire.
FLUX-CORE WIRE
E
-
7 0 T
-
GS
Weld strength, times
10,000 psi
Welding positions (0
for flat or horizontal,
1 for any position)
Tubular flux core wire
Flux type
AWS E71T-GS or E71T-11 is
recommended for this welder.
SOLID WIRE
ER
-
70 S
-
6
Weld strength, times
1,000 psi
Solid wire
Wire composition
ER-70S6 is recommended for this
welder.
WELD ANGLE
Weld angle is the angle at which the
nozzle is held during the welding
process. Using the correct angle
ensures proper penetration and bead
formation. As different welding
positions and weld joints become
necessary, nozzle angle becomes an
increasingly important factor in
obtaining a satisfactory weld. Weld
angle involves two positions - travel
angle and work angle.
Travel angle is the angle in the line of
welding and may vary from 5º to 45º
from the vertical, depending on
welding conditions.
Work angle is the angle from hori-
zontal, measured at right angles to the
line of welding. For most applications, a
45º travel angle and 45º work angle is
sufficient. For specific applications,
consult an arc welding handbook.
WIRE SPEED
The wire speed is controlled by the
knob on the front panel. The speed
needs to be
“tuned”
to the rate at
which the wire is being melted in the
arc. Tuning is one of the most critical
functions in wire feed welding. Tuning
should be performed on a scrap piece
of metal the same type and thickness as
that to be welded. Begin welding with
one hand “dragging” the gun nozzle
across the scrap piece while adjusting
the wire speed with the other hand.
Too slow of speed will cause sputtering
and the wire will burn up into the
contact tip. Too fast a speed will also
cause a sputtering sound and the wire
will push into the plate before melting.
A smooth buzzing sound indicates the
wire speed is properly tuned. For
aluminum
, wire speed is typically set
higher (7 - 9 speed range).
NOTE:
Repeat the tuning procedure
each time there is a change in heat
setting, wire diameter or type, or work
piece material type or thickness.
TRAVEL SPEED
The travel speed is the rate at which
the torch is moved across the weld
area. Factors such as diameter and type
of weld wire, amperage, position, and
Slag
Weld
Wire
Flux
(Gasless
only)
Work Piece
Shielding
Gas
Contact
Tip
Crater
Nozzle
Figure 9 - Weld Components
www.chpower.com
TRAVEL ANGLE
WORK ANGLE
5º - 45º
5º - 45º
Figure 10 - Weld Angle
