MIG and MAG welding methods (not quite correctly known as CO) are currently some of the most widely used welding methods in the world. MIG/MAG welders are thus gaining great popularity in both domestic and industrial use.

By definition, both are “arc welding processes that create metal joints by heating them with an electric arc that is created between a continuously fed welding wire and the weldment.” Simply put, the welder continuously feeds the welding wire through the welding torch, and the electric arc that is created when the wire contacts the weldment melts the metal, then solidifies, forming a weld.

What gas should be used for MIG and MAG welding?

The shielding gas CO ₂ (carbon dioxide) is used in MAG (Metal Active Gas) welding . Therefore, the term CO ₂ welding should only be used for MAG welding. CO ₂ is used pure or as a mixture of CO2 and argon (so-called corgon: 82% argon and 18% CO2), mainly for welding stainless steel. Exceptionally, we can also encounter three-component mixtures with an admixture of oxygen.

The difference between pure CO ₂ and a mixture of CO ₂ + argon is primarily in their properties during use , to which we must adapt the choice of a pressure reducing valve. Carbon dioxide cools significantly when expanding, which can cause problems with freezing and subsequently gas flow. Therefore, it is good to use a pressure reducing valve with heating. It is by adding argon that we eliminate this problem, and therefore it is generally recommended to use the mixture. The truth is that when using pure CO ₂ , the resulting weld is less porous, but this is a minimal difference that does not have a significant impact on the quality of the weld in ordinary and often professional welding.

Argon and helium are typically used in MIG (Metal Inert Gas) welding , mostly for welding aluminum and other non-ferrous metals.

Why are MIG/MAG methods called CO welding?

The popular, not entirely correct, name CO ₂ or CO welding is used precisely because of the MAG method, where carbon dioxide can be used as a gas. Even though carbon dioxide is not used in MIG welding, a MIG/MAG welder is often called a CO welder. Before various mixtures were used, CO ₂ was the most widely used gas and, despite the imprecise name, the name was extended to include MIG welding and is still used today.

What is the difference between the MIG and MAG method?

It can be said that the only difference between MIG and MAG welding is the type of shielding gas. One actively intervenes in the welding process (active), the other only protects it (inert). We explain the difference between MIG and MAG in more detail in the article Preparing for welding with a CO2 welder. Basics of CO2 welding.

Advantages of MIG/MAG welding over other methods

These welding methods are very popular worldwide for their high quality welds, and at low costs. MIG/MAG welding has the following advantages:

• the ability to join different types of materials and thicknesses,
• components and accessories are easily available and affordable,
• very high welding efficiency,
• possibility of welding in all positions, in an overhead position using special tubular wires,
• nice appearance of the weld bead,
• less heat input compared to other methods,
• minimum spatter and slag residues allowing for quick and easy cleaning of the weld (beautiful clean weld after quick cleaning, especially during pulse welding),
• It is intended for robotic applications, automation and semi-automatic applications.

Why use the MIG/MAG method?

• lower costs per meter of weld than with other welding methods,
• lower costs for additional material,
• minimal cleaning work after welding.

Limitation of MIG MAG welding

MIG/MAG welding is not suitable for outdoor welding, where the shielding gas is likely to be blown away by the wind. For outdoor welding, it is better to use MMA welding with a coated electrode.

MIG/MAG welders for hobby and professional use

Classic MIG/MAG welding is still one of the most widely used welding methods used in most companies, but also by smaller tradesmen. To achieve optimal welds, it is important to choose a welding source, i.e. MIG/MAG welder, for a specific application, along with accessories and filler material.