Best GAS for TIG Welding Aluminum

What is the best gas for TIG welding aluminum?

Is it pure Argon?

Stargon AL?

Argon Helium mix?

Argon

Pure argon is the most versatile and most commonly used shielding gas for tig welding aluminum.

In fact, Argon might be the only shielding gas you ever need.

For TIG welding up to 1/8" thick (3.2mm) aluminum, pure argon works fine.

But when you jump up to 1/4" thickness, you might benefit from either an argon helium mix, or a specialty gas like Stargon AL.

What is UHP Argon?

UHP stands fro "Ultra High Purity" and I know a few welders who weld high end aluminum products and who swear by UHP Argon for best results on products like custom valve covers, intake manifolds, and even custom hunting dox boxes made from diamond plate.

UHP Argon costs a bit more than standard welding grade argon but the benefits are a cleaner puddle and the last hundred psi in your tank is usually just a clean as the first.

Argon helium mix

Adding helium to your argon shielding gas by using a Y valve is a simple and easy way to add heat to the arc and supercharge your tig welder for aluminum.

The problem is that helium has become expensive and hard to get.

But it is still worth it in my opinion.

Here is what happens when you add helium to your argon shielding...

1. Increased heat input: Helium has a higher thermal conductivity than argon, which means it transfers heat more efficiently. Adding helium to the argon shielding gas increases the overall heat input to the weld pool, leading to higher temperatures and faster melting of the aluminum. You notice it right away because the aluminum seems to puddle immediately.
2. Increased arc voltage: Helium has a higher ionization potential than argon, resulting in a higher arc voltage. This higher voltage can lead to a more focused and concentrated arc, enhancing arc stability and control.
3. Improved arc cleaning action: The addition of helium can enhance the arc's cleaning action by increasing the arc energy. The higher energy arc helps remove oxides and impurities from the aluminum surface, resulting in a puddle that flows easily and a cleaner weld joint.
4. Increased penetration: Helium's higher heat conductivity and increased arc voltage can lead to deeper penetration in the weld pool. This can be beneficial when welding thicker aluminum sections, as it allows for better fusion between the base metal and filler material.
5. Narrower arc cone: The addition of helium tends to narrow the arc cone, making the arc more focused and concentrated. This narrower arc cone can provide better control and allow for precise welding in applications that require fine details or narrow weld beads.

It's worth noting that the specific effects of adding helium to argon can vary based on the helium-to-argon ratio used and the welding parameters. With a simple Y fitting, you can adjust the gas ratio to achieve the results you need.

 

Stargon AL

Stargon AL is a TIG welding gas that is a proprietary blend of argon with small ppm (parts per million) additions of active gases, (oxygen, nitrous oxide, and who knows what else because it's a proprietary blend).

Stargon AL is supposed to add more heat to the welding arc by using tiny ppm percentages of active gases.

Stargon AL works best with a gas lens setup as you can see on this page where I did some extensive testing comparing Stargon AL to pure argon and an argon helium mix.