Forney 190 MIG, Руководство пользователя

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• Attach the ground clamp to the bare metal to be welded, making sure of good contact;
• Make sure that the wire-roller groove in the roller corresponds to the diameter of the wire
being used.
• Plug the machine into a suitable outlet.
• Completely open the gas cylinder valve. Adjust the gas pressure regulator to the correct flow rate.
Some experience is required to adjust and use a MIG welder. In MIG welding two parameters
are fundamental: the welding voltage and the wire speed. The resulting welding current is a
result of these two settings.
• Set the voltage and wire feed controls to positions suitable for the thickness of the material to
be welded. Welding current varies in relationship to wire feed speed. For low welding current
output, the wire feed speed potentiometer should be set at the low end of the wire feed speed
scale. Turning the wire feed speed control potentiometer clockwise. Will result in increased
wire feed speed and welding current. Welding voltage is adjusted to match the wire feed
speed (welding current). Progressively select higher voltage positions while increasing wire
speed.
Increasing welding voltage leads to a longer arc (without substantially affecting the current).
Conversely, a decreased welding voltage results in a shorter arc (the current again is not
substantially changed). A change in wire diameter results in changed parameters. A smaller
diameter wire requires an increase in wire feed speed to reach the same current. If certain limits
are exceeded, a satisfactory weld cannot be obtained. Refer to welding set up chart on page
(14) These are:
A) Feeding wire too fast (with regard to the welding voltage) results in pulsing within the torch.
This is because the wire electrode dips into the puddle and cannot be melted off fast enough.
B) Setting welding voltage to high (with regard to the wire feed speed), will result in excessive
and unstable arc. Increase the voltage even higher and the contact tip will burn.
C) Excessive wire speed can be corrected through the arc voltage increase. The limit of this
adjustment depends on the thickness of the material to welded (a certain limit exceeded will
result in burnthrough).
Place the torch on the joint you want to weld: the angle between the torch and the nozzle should
be around 45°. The distance between the torch and the work piece should be approximately
1/2”. Lower the face shield and press the torch trigger to start the arc. When the arc has struck,
move the nozzle slowly from left to right along the joint. Adjust the wire feed speed until the arc
makes a “crisp” sound (experience will help you to recognize the right sound).
The machine should be set up as for mild steel except for the following changes:
• 100% ARGON as weld shielding gas.
• Ensure that your torch is set up for aluminum welding:
• The length of the torch cable should not exceed 10’ (it is advisable not to use longer torches).
• Install a teflon wire liner. Follow the instructions for changing the liner.
• Ensure that drive rolls are suitable for aluminum wire.
• Use contact tips that are suitable for aluminum wire and make sure that the diameter of the
contact tip hole corresponds to the wire diameter that is going to be used.
Welding Preparation
General Operating Instructions
Aluminum Welding