Tweco FP-260 - Manual (Page 13)

DO NOT use the cylinder if you find oil, grease or damaged parts. Inform your
gas supplier of this condition immediately.
Regulator Gas Flow Information
Before using regulator, read instructions thoroughly.
For general, small diameter wire MIG welding the regulator setting is from 15-40 CFH. Example: .030” wire
using 75/25 Argon/CO2 mix gas on 15 gauge sheet metal, gas flow from regulator should be set at 25 CFH.
MIG GUN
We recommend periodically checking the contact tips and the nozzle. These parts must be clean and not worn.
Replace the torch liner when the wire does not run smoothly.
MIG WELDING
In MIG (GMAW) welding, a continuously fed metal electrode (the welding wire) is melted into a welding pool
at constant and controlled speed. The wire is connected to a constant voltage pole while the workpiece is con-
nected to the other pole (See Figure 3). When the wire is fed and touches the workpiece, an electric arc is pro-
duced. The arc melts the wire that is deposited on the workpiece.
MIG welding uses a steel coppered wire as an electrode and an inert gas (CO
2
, CO
2
/Argon mix or pure Argon)
for protection of the weld pool.
The wire can be one of three types:
1. Solid wire - ALWAYS used with a protective gas.
2. Cored wire - Has a core of mineral powders to enhance its characteristics and is used with gas.
3. Gasless cored-wire - Has a core of mineral powders that, when burning, release the protective gas for the arc.
ALWAYS used without gas.
The welding unit consists of a DCpower source, a torch, a ground and a gas pressure regulator. Each power
source has a 7-position switch used to regulate the welding current, a potentiometer regulating the wire speed,
a potentiometer with a switch and a timer to set the spot welding time (for those models where this feature is
provided) . Welding current and wire speed are set considering the thickness of the material to be welded. The
thicker the material, the higher the welding current and the higher the wire speed. The wire speed can be fine
tuned during welding for better results.
ONLY experienced personnel should use the power sources.
WELDING TIPS
1. Keep the torch handle at 45º angle with respect to the workpiece. Maintain the nozzle about 1/4” (6 mm)
from the surface.
2. Move the torch handle with a careful and steady movement.
3. Avoid welding in areas with too much air movement. The air blows away the shielding gas from the weld
pool and causes porosity in the weld.
4. Keep the wire and its cover clean. DO NOT use rusted wire.
5. Avoid sharp bends and kinks in the welding hose.
6. If possible, clean the wire liner with compressed air when replacing the wire spool.
7. Periodically, remove the dust using low pressure (3-4 bar/45-60 PSI) from the inside of the power source, to
assure adequate heat dissipation from power source during operation.
IMPORTANT
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