Getting Started with MIG
MIG welding (Metal Inert Gas) is the most forgiving process for beginners — but only if your machine is set up right. Wrong settings cause more problems than bad technique. Here's how to dial it in from scratch.
The Three Variables
Every MIG weld comes down to three settings working together: voltage, wire feed speed (WFS), and travel speed. Change one and the others need adjusting.
Voltage
Voltage controls arc length and bead width. Too low and the wire stubs into the puddle. Too high and you get a wide, flat bead with spatter. A good starting point for 1/8" mild steel is 18–20V.
Wire Feed Speed
WFS controls amperage — faster wire feed means more heat. Most machines label this in inches per minute (ipm). For 0.030" wire on mild steel, start around 200–250 ipm and adjust from there.
Travel Speed
This one's on you. Move too fast and you get a narrow, ropy bead with poor fusion. Too slow and you overheat the metal. Aim for a consistent pace — the puddle should be about twice the width of your wire.
Starting Points by Material Thickness
- 18 ga (1.2mm): 17–18V, 150–175 ipm
- 1/8" (3.2mm): 19–21V, 200–250 ipm
- 3/16" (4.8mm): 21–22V, 250–300 ipm
- 1/4" (6.4mm): 23–25V, 300–350 ipm
These are starting points — use Pocket Welder Helper's MIG settings screen to get a precise recommendation for your material and thickness.
Reading Your Bead
A good MIG bead looks like a stack of dimes — evenly spaced ripples, consistent width, no undercut at the edges. If you see porosity (holes), check your gas coverage. If you see spatter, raise voltage slightly or slow down your wire feed.
Gas Selection
For mild steel, 75% Argon / 25% CO₂ (C25) is the standard mix. Pure CO₂ is cheaper but produces more spatter. Never use straight Argon on steel — it causes an erratic arc.
Quick Tip
Always test on a scrap piece of the same thickness before welding your actual project. Five minutes of testing saves hours of grinding.