You need 100% pure argon. Yes, just argon. No oxygen, no carbon dioxide, no funny business. Pure argon is the holy grail for most aluminum welding.
Why? Because aluminum is a drama queen. It forms a tough oxide layer the second it touches air. Argon blasts that layer away like a bouncer at a club. Without it, your weld looks like a melted pop-tart.
Wait, what about a mix?
I hear you. You’ve got a tank of “C25” (argon + CO2) from welding steel. Don’t use it. Seriously, don’t. That CO2 will turn your aluminum into a porous, sooty disaster. It’s like putting diesel in a Ferrari—it just won’t end well.
Stick to the pure stuff. Your welder will thank you. Your eyebrows will too (no explosions today).
