Shielding gas
Argon mix or 100% CO2 — which should I buy?
Quick answer
Buy an argon-CO2 mix for general MIG: cleaner beads, less spatter, better thin-sheet behaviour — and mixes dominate Australian counter sales for good reason. Buy straight CO2 only if cost is critical and your work is thicker steel where its deeper penetration and extra spatter are acceptable.
Trade-offs
| Gas | Penetration | Spatter | Thin sheet | Refill cost |
|---|---|---|---|---|
| Argon-CO2 92/8 | good, stable arc | low | excellent | $$ |
| Argon-CO2 80/20 | deeper | low-med | good | $$ |
| 100% CO2 | deepest | high | poor | $ |
Practical advice
Most Australian welders run 92/8 (Argoshield-style) and never think again. If you weld mostly 5 mm+ on farms, CO2's cheap refills can outweigh the cleanup time. Never run CO2 on TIG, and never run a steel mix on aluminium — both damage the work and the equipment.