So, you have taken on welding and you are almost ready to go. However, you are not quite familiar with shielding gases and their significance. At nexAir, we believe understanding the basics before starting a project is what helps us Forge Forward. Distinguishing the similarities and differences is key to a successful welding session. Below is a quick guide to give you a better understanding on TIG and MIG welding, as well as the best gas for each scenario.

What gases should you use for TIG welding?

• Pure Argon
• Helium
• Hydrogen

What gases should you use for MIG welding?

• Oxygen
• Carbon Dioxide
• Helium
• Argon

Let’s break it down.

TIG welding, short for Tungsten Inert Gas welding, is an arc welding process that produces the weld with a non-consumable tungsten electrode. This type of welding is versatile, allowing professionals to join a large range of materials. However, it is a much slower process compared to MIG welding, resulting in greater costs and longer lead times. It is important to note that this form of welding requires highly specialized training in order to ensure a precise and accurate outcome. As mentioned above, the gases used for TIG welding include Pure Argon, Helium and Hydrogen.

Pure Argon
Argon is the most commonly used inert gas for the TIG welding process. This is a top pick amongst welders because it can be used on metals such as mild steel, stainless steel and aluminum. Versatility is key in this industry.

Helium
An Argon and Helium mixture can be used in both TIG and MIG welding.

Hydrogen
In order to increase the heat input and protect against oxidation, it is recommended to combine a max of 5% Hydrogen and Argon.

Now that you know how the basics of TIG welding work, let’s introduce MIG welding and the favored gases.

MIG welding, also known as Metal Inert Gas welding, is a welding method in which the filler metal supplies the electric current to maintain the arc. Generally used for thicker materials, MIG welding is quick and cost effective. Although this method is easier to learn, its welds are not as precise as those done by TIG. The gases used for MIG welding include, Oxygen, Carbon Dioxide, Helium and Argon.

Oxygen
Oxygen can be combined with Argon to improve Argons arc stability. Be careful with the amount of Oxygen you use, as too much can lead to trapped air bubbles, resulting in a more brittle weld. It is recommended to use around 2-5% Oxygen, depending on the circumstance.

Carbon Dioxide
Blended with Argon, Carbon Dioxide allows for a deeper weld, but makes the arc more unstable as well as produces unwanted fumes.

Helium
Helium gas is lighter than air, which requires larger flow rates than Argon. Because you are using a larger quantity, this gas is less cost-effective.

Argon
Like TIG welding, Argon is also an excellent choice due to its low flow rate, good ionization and a more precise weld. Pure Argon is a common choice for most welding processes, but adding other substances such as Oxygen and Helium, can change the game and create a better, more efficient welding experience.

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Whether you are welding as a hobby or to make a living, understanding the basics of each gas is important. A good takeaway is to always be aware of what metals you are welding to make sure you are getting the best gas flow for that project. If you have any questions or concerns, nexAir is here to help our customers Forge Forward.