What Is The Best Gas For Mig Welding Mild Steel Without Spatter

what is the best gas for mig welding mild steel

By starting a new welding process, you may have asked yourself a question like this: what is the best gas for MIG welding mild steel? What would your answer be? Before you can reply to this type of problem, you first need to know what MIG welding is, why use it, and then explain what gas can be considered the best.

What Is MIG Welding And What Is It Used For?

MIG welding, or Metal Inert Gas Welding, is also known as Gas Metal Arc Welding (GMAW), and it involves the process of utilizing a solid electrode being continuously fed while shielding gas supplied from an external source and melting the electrode via some electrical power supply, then deposit in the weld joint, the molten material.

This welding can be used to weld all types of metals and alloys available commercially while guaranteeing high productivity as a low-cost welding process.

What Are The Different Types Of Welding Gases?

Welding gas involves heating a metal workpiece and filler material using a gas-fed flame to produce a weld. Several gases can be used as fuel. Generally, the gas consists of a mixture of oxygen and gas fuel to create a clean, hot flame. Below are some of the different types of welding gases:

  • Acetylene. This is a colorless and highly flammable gas and is known to be an excellent choice for welding, brazing, and cutting of alloy steels that is less than one inch thick. This gas can be mixed with oxygen gas, and this mixture is commonly known as oxy-acetylene, used to feed the welding torch. Acetylene is known to have a high heat release in the primary and secondary flame, known to have low heat. It is considered the hottest temperature of all commercially available gas fuel.
  • Argon. Argon is a noble gas consisting of less than 1% of the earth’s atmosphere. It is colorless, odorless, tasteless, and known to be non-toxic. Its use provides a clean environment free from nitrogen. This gas can be used for creating an inert gas shield while welding. To facilitate metal transfer in Gas Metal Arc Welding (GMAW or MIG) and enhance arc stability, argon should be blended with either Carbon Dioxide, Hydrogen, Oxygen, or Helium.
  • Hydrogen. Looking for a light gas to use? Then think hydrogen. At atmospheric temperatures and pressures, hydrogen exists as a gas. It is colorless, odorless, tasteless, and, most importantly, non-toxic. It can be used at a higher pressure, especially when compared to other gas fuels; this is why it is also used for processes involving underwater welding.
  • Methylacetylene-propadienyl petroleum (MAPP). From the name, it is evident that this is a gas mixture, more inert than any other combination. Hence, making it safe to use and for storage by hobbyists, recreational welders, Etc.
  • Carbon Dioxide. Carbon Dioxide (CO2) is a reactive gas and is the only one that can be used 100% pure in MIG welding without being mixed with an inert gas. It is the least expensive of the shielding gases.

Which Shielding Gas For MIG Welding Mild Steel Should I Use?

Before starting the welding process of mild steel, it is essential to consider certain things.

The first thing is the type of gas to use to guarantee you the best results. Most times, people make their choices based on what they have available, but careful research of the best gas can help your welding process in the long run.

mild steel tube welded

Mild steel tube welded

While some might seek information from the supply store for welders, others might seek to look at the manufacturers’ information on the welding wire as some manufacturers go the extra mile to provide a few choices range, including the best that will give the minimum acceptable result.

Some other option will be to contact welders as some of them have gas and welding electrode recommendation guide on the inside panel, which helps illustrate options with the aid of pictures. Most times, the gas to use for mild welding steel is dependent on several options, including cost and availability. There are several gases to use for mild welding steel:

  • Argon
  • Carbon dioxide (CO2)
  • Oxygen
  • Helium

Among these, Helium is the least used. Most of the gases used are mixtures consisting of either Oxygen, Carbon Dioxide, or Argon.

The CO2 used 100% pure is good and is the least expensive choice and provides deep penetration, but the arc is not stable, and increases spatter with this gas. A 90% Argon e 10% Carbon Dioxide works well for all-purpose shielding gas for mild steel and reduces the amount of spatter.

Video: Tips for Welding Mild Steel

Should I Use A Disposable Or Refillable Gas Cylinder?

When choosing the cylinder to use, you can either use a disposable or refillable bottle.

Most times, the cost is a factor to consider when choosing the type of gas cylinder to use. Disposable cylinders have low cost at the initial stage and are highly portable.

So, if you are working on a budget, then this is an option you should consider.

Refillable cylinders are more expensive to acquire initially but get cheaper over time.

The choice, therefore, depends on how big the work you need to get done, or how frequently you need it.


Does the choice of MIG welding wire affect the welding quality?

While there are several options of welding wire available on the market today for MIG welding, some popular ones are SuperArc L-50TM and L-56TM. What differentiates these wires is the number of deoxidizers found in each. The super arc L-56 wire carries more deoxidizers, which implies it has more built-in cleaning action to handle welding contaminants such as rust, oil, dirt, Etc. Both wires have tensile strength designed for MIG mild welding or carbon steels. 

Does the type of shielding gas affect the quality of the finished weld?

Using carbon dioxide gas or in mixture with other gas provides adequate shielding if you have a flat bead profile, right wetting action, or less spatter. The option of adding argon to the carbon dioxide can be useful as the reactivity of the gas reduces, making the arc more stable as a result of the inertness of the argon. 

Are there other suggestions for higher-quality MIG welds?

A good electrical ground is important and should not be overlooked. Those starting welding for the first time often makes the mistake of attaching the electric ground (work clamp) to a painted panel or rusty surface, which are electrical insulators and do not allow the welding current to flow properly. Find here the review of 10 high-grade 220V MIG welders.


It is advisable to do your research and know the best welding gas and process that works best, just as described in this article. Few companies offer a full quality range of MIG solutions you can reach out to online or physically.

Finally, don’t forget, safety first!

Similar Posts