Your first 20 hours of welding

Your first twenty hours of welding will produce ugly beads, occasional stuck arcs, and at least one moment of genuine satisfaction. Here's what actually happens — stage by stage — and what to focus on so the frustration has a point.

By The JustBeginning Editors · Published May 30, 2026

MIG welding has a reputation as the easy entry point to metalworking, and that’s mostly true — but “easy” relative to TIG or stick still means a real learning curve. You will make bad welds. A lot of them. The trick is knowing what bad welds are telling you, so you can adjust instead of guessing.

This is what your first twenty hours actually look like, with the things that matter at each stage and the things you’ll be tempted to worry about but shouldn’t.

Hours 1–3: Getting the arc to start

Your first session is about one thing: getting a stable arc and keeping it going. Everything else is secondary.

Before you strike a single arc, spend ten minutes on setup:

Wire and polarity. If you’re running flux-core wire, your ground (work) clamp connects to the negative terminal and the gun connector to positive (DCEN — electrode negative). If you’re running solid MIG wire with gas, it’s reversed (DCEP). Your welder manual will show this. Getting polarity wrong produces a spattery, ugly arc — and beginners often blame their technique when it’s actually the polarity.
Wire speed and voltage. Most 140-amp MIG welders have a chart inside the door: metal thickness → wire speed → voltage setting. Use it. For 1/8” steel and .030” flux-core wire, you’re typically looking at around 4–5 on the voltage dial and 40–50 on the wire speed. Start there.
Gun angle. Hold the gun at about 10–15 degrees pushing (drag for flux-core, push for solid wire). You’ll hear the difference — a smooth, consistent “frying bacon” sound means your settings and angle are close.

Your first beads will wander. The weld will be uneven, bumpy, and probably have some holes. That’s completely normal. You’re not controlling anything yet — you’re just learning what the arc feels and sounds like.

a man wearing a blue protective gear working on a machine — Photo by Heber Davis on Unsplash

Hours 4–10: Learning the four variables

By hour four, you’ve heard enough arcs to know what “sounds right.” Now you start learning to adjust. Every weld problem traces back to one of four variables:

Wire feed speed. Too slow and the arc sputters and sticks. Too fast and the wire pushes into the puddle and you get a messy, convex bead. The right speed produces a steady sound and a bead that sits flat.

Voltage. Too low and the bead piles up narrow and tall (cold). Too high and you’re burning through the metal (hot). The right voltage creates a wide, flat bead with good fusion at the edges.

Travel speed. Too slow and the bead gets fat and shapeless — you’re piling metal up. Too fast and the bead is thin and you’re not getting enough penetration. A consistent travel speed at around 8–12 inches per minute for flat position is typical.

Gun angle. The wrong angle changes where the heat goes. Too steep and you’re pushing the puddle. Too shallow and you’re not directing the arc at all. 10–15 degrees from vertical is the range to stay in.

The single most valuable thing you can do in these hours is practice on scrap with specific intent: run a bead and then evaluate it. Flat and evenly-spaced ripples = good. Irregular, porous, or humped = one of your four variables is off. Learn to diagnose before you adjust.

This is also when you should start understanding joint types: butt joints (two pieces edge to edge), T-joints (one piece perpendicular to another), and lap joints (one piece on top of another). Each requires slightly different gun position and travel. Practice each type separately.

a welder working on a piece of metal — Photo by Chris de Tempe on Unsplash

Hours 11–20: Building your first real project

Around hour ten, your flat-position beads start looking like welds instead of glue. You won’t have them dialed in, but you’ll know when you’re close and what to adjust when you’re not.

This is when you should build something. Not attempt to build something — actually finish it. A small frame welded from 1” square tubing. A simple bracket. A set of hooks for the garage wall. Something with right angles and multiple joints.

Why now? Because building under real constraints teaches things that practice beads don’t. When your part moves because you didn’t clamp it well enough. When heat distortion pulls your frame out of square and you have to figure out how to compensate. When your workpiece has a painted area you forgot to grind off and the arc goes everywhere. These are lessons you can only learn by running into them.

A few things will become obvious fast:

Tack first, weld second. Never try to run a full weld on an unclamped joint. Tack both ends, check your square, then tack in the middle. Weld after the geometry is confirmed.
Vertical and overhead welding are different skills. Your horizontal flat-position technique won’t transfer directly. The puddle behaves differently when gravity is pulling it sideways or down. Don’t start there — but know it’s coming.
Grinding is part of welding. Clean your base metal before welding (bare steel only — grind off rust, scale, and paint) and clean your bead after if appearance matters. An angle grinder with a flap disc does both jobs cleanly.

By hour twenty, you’ve got a working understanding of flat-position MIG. You can set up your machine for a job, diagnose problems from the bead profile, and finish something. You’re not fast. You’re not consistent across joint types yet. But you’re actually welding — not just practicing.

a man in a red jacket working on a piece of metal — Photo by Kato Blackmore 🇺🇦 on Unsplash

What your welds are telling you

Every bead is feedback. Common problems and what they mean:

Porosity (tiny holes or pits): Contamination — dirty base metal, or (for gas-shielded MIG) gas coverage issues. Clean your metal and check your gas flow rate (usually 20–25 CFH).
Undercut (a groove along the edge of the bead): Too fast travel speed, too much heat, or gun pointed too far to one side. Slow down and center your angle.
Convex/humped bead: Wire speed too high relative to voltage, or travel speed too fast. Lower wire speed or slow down.
Incomplete fusion (bead sitting on top, not merging with base metal): Too cold — increase voltage or slow down. Common on heavier stock with a lower-amperage machine.
Spatter everywhere: Flux-core produces more spatter than gas MIG by nature. But excessive spatter usually means voltage too low or wire speed too high. Adjust and compare.

Nobody welds perfectly in their first twenty hours. The goal isn’t perfect beads — it’s beads you understand.

What to do at hour twenty-one

Take a welding class at a community college. Not before hour twenty — at that point you lack the context to absorb what they’re teaching. After twenty hours, a three-session class with an instructor will identify your two or three specific problems and give you drills. Worth every dollar.
Learn to weld vertical up. It’s the next most-useful position after flat. Same basic technique, but you’re weaving side to side to keep the puddle from running down.
Start caring about metallurgy. Not deeply — but understanding the difference between mild steel (what you’ve been welding), galvanized (do not weld without ventilation), and stainless (needs different wire and gas) saves you problems.

Ready to kit out your shop? See our welding gear guide for the welder, helmet, and consumables worth buying first — and what to skip until year two.