Elettro MIG 245 DOUBLE TORCH Betriebsanleitung Seite 10

S – Gas fitting SIDE B
U – Gas fitting SIDE A
4 WELDING
4.1 INSTALLATION
Make sure that the wire diameter corresponds to the diameter
indicated on the wire feeder roller, and that the selected program is
compatible with the material and type of gas. Use wire feeder rollers
with a "U"-shaped groove for aluminium wires, and with a "V"-
shaped groove for other wires.
4.2 THE MACHINE IS READY TO WELD
When using the torch WEL3105, follow the instructions enclosed.
• Connect the torch to the central connection P on side B.
• Connect the earth clamp to the workpiece.
• Set the switch J in position B.
• Set the switch Q to 1.
• Connect the gas cylinder to the fitting S.
• Remove the gas nozzle.
• Unscrew the contact tip.
• Insert the wire in the wire liner of the torch, making sure that it is
inside the roller groove and that the roller is in the correct position.
• Press the torch trigger to move the wire forward until it comes out of
the torch.
• Caution: keep your face away from the gun tube assembly while
the wire is coming out.
• Screw the contact tip back on, making sure that the hole diameter is
the same as that of the wire used.
• Assemble the gas nozzle.
4.3 WELDING CARBON STEELS WITH GAS PROTECTION.
In order to weld these materials you have to:
• Use a welding gas with a binary composition, usually ARGON +
CO2 with percentages of Argon ranging from 75% up. With this
blend, the welding bead will be well jointed and attractive. Using pure
CO2 as a protection gas will produce narrow beads, with greater
penetration but a considerably increase in splatters.
• Use a welding wire of the same quality as the steel to be welded. It is
best to always use good quality wires, avoiding welding with rusted
wires that could cause welding defects.
• Avoid welding rusted parts, or those with oil or grease stains.
4.4 WELDING STAINLESS STEEL
Series 300 stainless steels must be welded using a protection gas with
a high Argon content, containing a small percentage of O2 or carbon
dioxide CO2 (approximately 2%) to stabilize the arc.
Do not touch the wire with your hands. It is important to keep the
welding area clean at all times, to avoid contaminating the joint to be
welded.
4.5 WELDING ALUMINIUM
In order to weld aluminium you have to use:
• Pure Argon as protection gas.
• A welding wire with a composition suitable for the base material to
be welded.
WEL2600
• Use mills and brushing machines specifically designed for
aluminium, and never use them for other materials.
• In order to weld aluminium you have to use the torch WEL3105.
5 WELDING DEFECTS
1 DEFECT- Porosity (within or outside the bead)
CAUSES • Electrode defective (rusted surface)
• Missing shielding gas due to:
- low gas flow
- flow gauge defective
- regulator frosted due to no preheating of the
CO2 protection gas
- defective solenoid valve
- contact tip clogged with spatter
- gas outlet holes clogged
- air drafts in welding area.
2 DEFECT - Shrinkage cracks
CAUSES • Wire or workpiece dirty or rusted.
• Bead too small.
• Bead too concave.
• Bead too deeply penetrated.
3 DEFECT - Side cuts
CAUSES • Welding pass done too quickly
• Low current and high arc voltages.
4 DEFECT - Excessive spraying
CAUSES • Voltage too high.
• Insufficient inductance.
• No preheating of the CO2 protection gas
6 MAINTAINING THE SYSTEM
• Shielding gas nozzle
This nozzle must be periodically cleaned to remove weld spatter.
Replace if distorted or squashed.
• Contact tip.
Only a good contact between this contact tip and the wire can ensure a
stable arc and optimum current output; you must therefore observe the
following precautions:
A) The contact tip hole must be kept free of grime and oxidation
(rust).
B) Weld spatter sticks more easily after long welding sessions,
blocking the wire flow.
The tip must therefore be cleaned more often, and replaced if
necessary.
C) The contact tip must always be firmly screwed onto the torch body.
The thermal cycles to which the torch is subjected can cause it to
loosen, thus heating the torch body and tip and causing the wire to
advance unevenly.
• Wire liner.
This is an important part that must be checked often, because the wire
may deposit copper dust or tiny shavings. Clean it periodically along
with the gas lines, using dry compressed air.
The liners are subjected to constant wear and tear, and therefore must
be replaced after a certain amount of time.
• Gearmotor group.
Periodically clean the set of feeder rollers, to remove any rust or metal
residue left by the coils. You must periodically check the entire wire
feeder group: hasp, wire guide rollers, liner and contact tip.
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