Argon. Unless you’re specifically doing something really abnormal there’s a reason it’s the most common shielding gas. Compared to the rest of the process the s

Argon. Unless you’re specifically doing something really abnormal there’s a reason it’s the most common shielding gas. Compared to the rest of the process the shielding gas shouldn’t be much of the total cost. If you want to minimize cost don’t rent your cylinder. You can usually find a cheap one used and just exchange it on your first refill if it’s within test date.