The correct standard procedure for using a MIG welder

MIG welding is a high-efficiency method with precise accuracy, offering high economic effectiveness. However, not everyone knows how to use and select a welding machine suitable for their needs. Let’s explore with RX Tradex how to use Mig welding machine correctly and choose the most suitable one for your requirements!

1. Introduction to Mig Welding Machines

The Mig welding machine operates on the principle of melting a consumable electrode protected by an external gas shield, ensuring high-quality welds throughout the welding process. When the welding electrode heats and melts, it is immediately shielded by an inert gas (such as Helium, Argon) or an active gas (such as CO2) to prevent nitrogen and oxygen from contaminating the weld, thereby enhancing its durability compared to conventional welding machines.

The Mig welder is capable of excellent semi-automatic and automatic welding, providing continuous welds without interruptions and with high precision. Furthermore, it can weld various metals (such as iron, stainless steel, aluminum, copper, etc.), making it widely used in large industrial sectors.

Key components of the Mig welding machine include the power source, welding wire, shielding gas, welding torch, rectifier, and wire feeder device.

• Power source: This box functions to demonstrate the operating principles and technology of the entire welding machine, providing stable electrical power guidance for the welding process. The power source is typically single-phase or three-phase, supplying voltage and current suitable for the welding requirements of different materials.
• Welding wire: The welding wire conducts electrical current to the molten pool and supplies a portion of the melting metal for the weld pool. During Mig welding, the appropriate diameter of the welding wire ranges from 0.8 to 2.4mm.
• Shielding gas: This gas or gas mixture (such as Ar, He, or Ar + He) does not react with liquid metals during welding or is certain active gasses (such as CO2; CO2 + Ar, …) that displace air, pushing it out of the welding area to inhibit adverse effects.
• Welding torch: It consists of the torch body, nozzle, contact tip, gas nozzle, and gas cup.
• Rectifier: The welding rectifier converts direct current into alternating current and vice versa, adjusting the current direction as needed for welding.
• Wire feeder device: This device pulls the welding wire from the wire spool and feeds it evenly into the conduit device to deliver it to the welding torch. The wire feed speed can be adjusted within a range of 1-18 meters per minute and remains constant throughout the welding process

2. Using Mig Welding Machines

The process of using a Mig welding machine starts with proper machine setup to ensure efficiency and safety during welding:

Step 1: Installing the welding wire spool into the Mig welder

Open the side cover of the welding machine and unlock the spool holder and wire guide. Insert the spool onto the holder, moving it counterclockwise, and then lock the spool in place. If using a 0.8mm wire spool, ensure it aligns with the 0.8mm groove on the wire feed wheel. Similar alignment applies for 1.0mm wires labeled with V0.1. Thread the welding wire through the hole, pass it through the wire feed wheel and the protruding welding torch tip by approximately 2-2.5cm. Finally, relock the wire guide, and close the welding machine cover.

Step 2: Installing and connecting the welding torch lead to the CO2 machine

Attach the torch lead to the Mig welding machine socket, check the hose’s position, and adjust the gas valve to standard settings. Tighten securely to prevent gas leakage. Next, connect the ground clamp to the socket. Install the pressure gauge into the gas cylinder, use a wrench to fix the connection points to prevent gas leakage, then adjust the gas flow to the number 5. The remaining gas hose is used to plug into the back of the machine, then plug the gas gauge plug into the 36V socket behind the machine.

Step 3: Insert the welding wire into the welding gun

Remove the gun and check the welding nozzle before welding. Then press the wire reel button until the welding wire protrudes from the gun.

Step 4: Plug the power cord and turn on the machine switch

Should position the MIG wire and welding gun about 1-2 mm away from the workpiece for a strong and aesthetically pleasing weld.

With a CO2 gas welding machine, you can squeeze and release quickly for a strong fusion weld, but for machines without gas, hold for about 2 seconds while moving the welding gun steadily.

Ensure the current is accurately adjusted to prevent spatter and create a smooth surface on the finished product.

3. Tips for Choosing a Mig Welding Machine

Choose according to usage needs:

For light industry, machines with a duty cycle of approximately 20% and an output current of ≤ 230 Amps are the optimal choice. For heavy industry, machines with a duty cycle ranging from 60-100% and an output current of >300 Amps are the best option.

Choose according to power source:

Consider the power source you will use to select a suitable machine. Single-phase power is suitable for households, small workshops, and small-scale manufacturing. Three-phase power is suitable for larger workshops and industrial zones. Additionally, there are Mig welding machines available that can automatically operate on both single-phase and three-phase power without requiring a power conversion device. In cases where grid power is unavailable, lightweight and compactly designed machines are preferable for portability.

To see, experience, and receive direct consultation on the most advanced Mig welding machines available today, visit the Vietnam Manufacturing Expo (VME) organized by RX Tradex in August!