Learning MIG welding is a great way to start a career in welding or to reinforce what you already know. In this blog post, WeldFAQ will cover the basic MIG welding techniques. These techniques will help you get started with MIG welding and help you to achieve successful results.
Basic MIG welding techniques
1. Preparing the metal
To prepare the metal for MIG welding, it is important to clean the surface to be welded and remove any rust, paint, oil, or other contaminants that could weaken the weld or cause porosity. This can be done through sandblasting, grinding, or using a chemical cleaner. It is also important to properly align and fit the metal pieces to be welded, to ensure a strong and uniform weld.
2. Setting the right welding parameters
Setting the right welding parameters is crucial for achieving a successful MIG weld. The voltage should be adjusted to match the thickness of the metal being welded. The wire feed speed should be adjusted to match the desired welding speed and the diameter of the filler wire.
The amperage should be set based on the diameter of the filler wire, the welding position, and the type of shielding gas being used. The welding speed should be set based on the desired final appearance of the weld and the equipment being used. Moreover, the flow rate of the shielding gas should be set based on the welding position, the welding speed, and the diameter of the filler wire.
It is important to follow the manufacturer’s guidelines and best practices for setting the welding parameters for a specific MIG welding setup. The parameters may need to be adjusted for different types of metal, different welding positions, and different welding applications.
3. Choosing the right filler wire
Choosing the right filler wire for MIG welding is important as it affects the quality and strength of the weld. The filler wire should be chosen based on the welding position, whether it’s flat, vertical, or overhead. The filler wire should match the intended use of the weld, such as structural or cosmetic welding.
Based on the welding current being used and the filler wire’s diameter, the filler wire should be selected. The shielding gas being utilized, such as argon or carbon dioxide, should match the filler wire. The filler wire needs to adhere to any rules or specifications set forth by the sector or use, such as AWS or ASME standards.
4. Maintaining a constant weld pool
Maintaining a constant weld pool is important for achieving a consistent and uniform MIG weld. A weld pool is the liquid metal that forms at the base of the weld and is used to build the bead. Hold the welding gun at the correct angle to ensure that the filler wire is directed into the center of the weld pool.
Adjust the wire feed speed to match the welding speed and the diameter of the filler wire. You also adjust the voltage to match the thickness of the metal being welded and to maintain a stable arc. Ensure proper shielding gas coverage to protect the weld pool from atmospheric contamination and to stabilize the arc.
5. Maintaining proper shielding gas coverage
Maintaining proper shielding gas coverage is important for ensuring the quality and integrity of the MIG weld. Shielding gas protects the weld from atmospheric contamination and helps to stabilize the arc.
It is important to follow the manufacturer’s guidelines and best practices for the specific MIG welding setup being used, as the shielding gas flow rate and pressure may vary based on the equipment and type of shielding gas being used.
6. Ending the weld
To end the MIG weld properly, the following steps should be taken:
- Gradual reduction of current: Gradually reduce the current as the end of the weld is approached, to prevent an abrupt stop that could cause porosity or cracking in the weld.
- Wire stub removal: Once the current has been turned off, the wire stub should be removed by breaking it off or by using a wire cutting tool.
- Cool down: Allow the weld to cool down naturally, without disturbing it, to prevent cracking or warping.
- Clean up: Clean up any slag or spatter from the surface of the weld to ensure a clean and uniform appearance.
It is important to follow the manufacturer’s guidelines and best practices for ending the MIG weld, as the specific procedures may vary based on the equipment and type of filler wire being used.
7. Inspecting the weld
Inspecting the weld after MIG welding is important to ensure that it meets the desired specifications and has proper penetration and bead appearance. Look for any cracks, porosity, or other defects in the weld. Check that the bead is uniform and that the penetration is consistent throughout the weld.
It is important to follow any industry or regulatory standards for weld inspection, such as AWS or ASME standards. A qualified inspector should perform the inspection, as they are trained to identify and evaluate welding defects.
Welding is an essential skill for any technician, and the basic MIG welding techniques covered in this article are the foundations for more advanced techniques. By understanding the basics of MIG welding, you can build a strong foundation for more advanced welding techniques and achieve high-quality results.