How to weld: your first bead with a wire feed welder
The first session with a mig or flux core welder: prepare the metal, set up from the machine's chart, hold the gun, run a bead, and read what you made.
This page is for your first hour with a wire feed welder, mig or flux core. It assumes you have the safety gear on and a clear space, as set out in welding for beginners.
The short version: clean the metal, clamp the ground to clean steel, set the machine from its own chart, hold the wire about a finger width from the work, pull the trigger, and move at a steady pace while watching the puddle, not the arc.
Before you strike an arc
Helmet set to the right shade for your amps (see the shade chart), gloves, long sleeves, glasses under the helmet, boots. Flammables moved away, air moving, extinguisher in reach. Anyone nearby warned not to look at the arc.
1. Prepare the metal
Start with mild steel offcuts around an eighth of an inch thick. Grind or sand to bright, shiny metal where you will weld. Mill scale, rust, paint and oil all cause porosity (small holes) and poor fusion. Clean a second patch for the ground clamp. A poor ground connection causes more beginner trouble than any setting.
2. Set up the machine
- Wire and polarity. Flux core and gas mig usually need opposite polarity, which means swapping two leads inside the machine. The manual shows which way round. Getting this wrong gives a harsh, spattery arc.
- Drive roll and tip. The drive roll groove and the contact tip must match the wire size. Flux core wire is soft, so it uses a knurled roll and light tension.
- Gas, for mig only. Open the cylinder, set the flow your manual gives, and check for leaks at the fittings. Which gas to buy is covered in mig welding gas.
- Voltage and wire speed. Use the chart on your machine for your wire and thickness. Every machine’s chart is its own. We cover why in welder duty cycle: the same badge can hide very different machines.
3. Get comfortable
Most bad beads are a body position problem. Sit or stand so you can move the gun along the whole practice line without stretching. Brace a forearm or the side of your hand on the bench. Use both hands. Do a dry run with the trigger released to check nothing snags.
4. Hold the gun
- Stickout. The wire should poke out of the contact tip by roughly a finger width. Too long and the arc goes soft and spattery.
- Angle. Tilt the gun ten to fifteen degrees from vertical. With flux core, drag it, tip pointing back at the puddle. With gas mig, most people push.
- Aim. On flat plate, straight down the line. On a joint, split the angle between the two pieces.
5. Run the bead
Drop the helmet, or let it darken. Pull the trigger and hold still for a beat until a molten puddle forms, about as wide as you want the bead. Then move. Watch the puddle and its leading edge, not the bright arc. Keep the puddle the same size by keeping your speed the same. A steady sizzle, often compared to frying bacon, is the sound to aim for. Loud popping and spitting means something is off.
Release the trigger at the end and hold the gun in place for a second. With flux core, let it cool, then chip and brush off the slag. The metal stays hot long after it stops glowing, so use pliers.
6. Read what you made
| What you see | Likely cause |
|---|---|
| Tall, narrow bead sitting on top | Too cold for the thickness, or moving too fast |
| Wide, flat bead, or a hole burned through | Too hot, or moving too slowly |
| Lots of spatter, harsh sound | Wrong polarity, stickout too long, voltage off |
| Small holes in the surface | Dirty metal, no gas flow, or wind on the gas |
| Uneven, wandering bead | Unsteady hand or awkward position; brace and do a dry run |
Change one thing at a time and run another bead beside the last. A longer list, by symptom, is in beginner welding mistakes. Number them with a marker so you can see what each change did.
7. Then join two pieces
Once flat beads look even, tack two pieces together with short welds at each end, check they are square, then weld the joint. Try a lap joint first, then a T joint, then a butt joint with a small gap. Cut or break a few apart to see how far the weld went in. When those look even, pick something from welding projects for beginners.
Where this stops
Practice teaches consistency. It does not certify anything. This site never says a weld will hold, and looking sound is not the same as being sound. Trailers, hitches, stands, lifting gear and anything under pressure belong to a certified welder.
If you are still choosing a machine, best welder for beginners ranks five by what they need from your outlet.
Frequently asked questions
Do you push or pull when welding?
With flux core, drag: point the gun back at the puddle and pull it along. The shop rhyme is that if there is slag, you drag. With gas mig on steel most people push, pointing the gun in the direction of travel, which gives a flatter bead and a better view. Your machine's manual will say which it recommends.
What settings should I use?
Start from the chart for your machine, usually inside the wire compartment door. It gives voltage and wire speed for your wire size and metal thickness. Charts differ between machines, so numbers from a video or another welder will not transfer. Adjust in small steps from the chart.
Why does my weld sit on top of the metal like a rope?
Usually too little heat for the thickness, moving too fast, or dirty metal. Check the chart setting for your thickness, clean to bright metal, make sure the ground clamp is on clean steel close to the weld, and slow down.
Why does my wire keep stubbing or burning back to the tip?
Stubbing, where the wire punches into the work, usually means wire speed is too high for the voltage. Burning back to the contact tip usually means wire speed is too low or you are holding the gun too close. Also check the drive roll tension and that the liner and tip match the wire size.
How do I know if my weld is good?
You can judge consistency by eye: even width, even ripples, edges blended into the base metal, no holes or deep grooves. You cannot judge strength by eye. Breaking practice pieces shows how far the weld went in. For anything that carries a load, the judgment belongs to a certified welder or inspector.
What metal should I practice on?
Mild steel offcuts around an eighth of an inch thick. It is cheap, forgiving and thick enough that you will not burn through while you learn. Grind it to bright metal first. Avoid galvanized or plated steel, which gives off harmful fume, and leave thin sheet until your beads are consistent.