How to Weld - TIG Welding

Step 5 Turn on the Gas

For aluminum, use pure argon.

For steel, you would use an argon/carbon dioxide mixture.

The gas is important to keep the weld from becoming corroded, as metal will rust (or in the case of aluminum, oxidize) ridiculously quickly at the high temperatures the metal reaches.

Comments

[CHEVY6998]

ANY process ofTIG whether it be DC or AC, Steel/Stainless/ or Aluminum should all use only 99.9% purified Argon. 75/25 is not inert and contaminate your welds. This exceptions to this rule and exotic alloys such as Titanium. Ti requires the introduction of Helium and controlled chambering.

[Fredrick_chilton]

I second Chevy6998 I TIG weld for a living, and know for a fact that you only use purified argon for the most common types of welding (Aluminum, Carbon steel, Stainless steel). With the exception of the introduction of helium, hence the reason some people refer to TIG as "heli-arc" (pronounced Heely-ark) If you use an argon/CO2 mixture, you will realize it RIGHT AWAY. Why? Your tungsten will start burning up, turning black, throwing sparks, and "hissing." In other words, you will ruin your Tungsten tip. Also, you need psi to be set at 15-20 psi. 15 will do just fine in most conditions, preventing the waste of gas.

[JoshuaTerrell]

Thirded. The only gases used in TIG processes are Argon, Helium, and rarely Nitrogen. Argon provides a more stable arc, whereas Helium produces a "hotter" arc. Nitrogen is occasionally used to weld deoxidized copper. Very few TIG processes use C02 as a stabilizing agent, and usually in low ratios (90/10) for exotic metals.

[ratz2]

Agree with all above. Never heard of using CO2, except from Joshua above for exotic metals.