Welcome to a multi-part series aimed at introducing the novice and intermediate garage fabricator to some cool new equipment and tips on how to use it. This month, we’re kicking it off with the most basic and fundamental of these processes: MIG welding steel.
While MIG welders aren’t as inexpensive as a simple buzz-box arc welder (or even a couple batteries and a pair of jumper cables), MIG welding is immeasurably easier. As a novice, you’ll be able to make cleaner, stronger, better welds with a MIG machine sooner than with other welding processes. But when selecting a MIG machine you really should weigh the most obvious factor (budget) against your intended use and skill level not only at present, but 10 or 20 years down the road. Because when you buy a good MIG machine, chances are it’ll be for life.
The Millermatic 212 can run...
The Millermatic 212 can run wire ranging from 0.023- to 0.045-inch, but the Auto-Set feature only works with the more-common 0.030- or 0.035-inch. Notice the newly incorporated angle of the wire drive system that all but eliminates wire feeding jambs and ensures smooth operation. The angle also gets the gun liner pointed down towards the floor and not straight out, so you’re way less likely to bend or damage it bumping into things.
When you consider the current lineup from Miller Electric, the company has a machine for just about any budget and skill level. The Millermatic 180 with Auto-Set usually has a street price of under $900 and will be able to handle just about any mild-steel job you can throw at it and will accommodate a spool gun, but like Miller’s bigger machines, it runs off of 208/230V, single-phase current. That pretty much means it’ll run on 208- to 230-volt household current or anything in between. We’ll call it 220-volt for continuity through this series. If you need the flexibility of either 220- or 110-volt household current, the Millermatic 211 has both the Auto-Set feature and spool gun ability but includes Miller’s MVP (multi-volt plug) for about $200 more. On the plus side, machines like these are smaller and will fit under a garage cabinet or can be stowed on a shelf when not needed. However, their duty cycles (length of time of continuous welding before cool-down is required) are shorter than the larger machines.
Of the larger machines, we think the Millermatic 212 used in this story represents the best compromise between performance, value, flexibility, and price. At around $1,700 (street pricing), it’s about $500 less expensive and packs more features than its bigger Millermatic 252 brother and has a duty cycle more than double that of the smaller 211. Although it won’t weld 1⁄2-inch-thick steel in a single pass like the more-powerful 252, the 220-volt 212 features the company’s innovative Auto-Set feature for dummy-proof voltage and wire speed settings and is still rated to weld 3⁄8-inch-thick steel in a single pass. That’s about the max any garage enthusiast will need to weld, plus it will still do finer jobs like sheetmetal and can run a spool gun for welding aluminum. Which reminds us, tune in next time to learn more about MIG-welding aluminum.
Miller’s Auto-Set automatically...
Miller’s Auto-Set automatically adjusts voltage and wire speed based on your wire diameter and material thickness. The 212 comes with Miller’s Material Thickness Gauge (PN 229-895) so you can accurately set the material thickness, then set for your wire size. The blue light comes on and you’re in Auto-Set mode. Or, you can adjust the welder manually the old-fashioned way. Unlike older machines with the setting information inside the drive cover, the 212 has an EZ-Access consumable compartment located under the flip-down parameter chart right at the front of the machine.
The 212 comes with a regulator...
The 212 comes with a regulator and hose assembly. You can reverse the polarity to run flux-core wire, but if you pay this much for a MIG machine, you’ll be running shielding gas. For welding mild steel, C25 (75 percent Argon and 25 percent Carbon Dioxide) is best, although you can run straight carbon dioxide. You can buy or rent gas cylinders at your local welding supply shop. Miller’s EZ-Change Low Cylinder Rack allows you to roll larger bottles straight on the cart without lifting.
Millermatic 180 or 211 units...
Millermatic 180 or 211 units can run on 110-volt household current. But for the 212 and 252 (or to get max voltage from the 211) you’ll need a 220-volt outlet installed in your garage. Use a qualified electrician. If you have an electric dryer, you can get a length of heavy wire and the correct socket ends to match your wall outlet and welder at your local home supply store. Keep the overall length of the extension cable to under 25 feet to avoid amperage drop, and make sure your breaker is rated for at least 30 amps.
Once you have your welder...
Once you have your welder all set up, spray some anti-splatter spray (Pam cooking spray works as well) onto the tip and nozzle to keep weld spatter from sticking, then run a length of wire out and cut it off about 3⁄4-inch from the nozzle. Ensure your shielding gas is working as well. We generally set our regulator to deliver 20 cfm. If you’re working outside and it’s windy, you can up the gas a bit to help keep the welds clean.
When welding any material,...
When welding any material, cleanliness is crucial. Make sure your material is completely free of dirt, grease, and rust. Be careful using chemicals like brake cleaner, since they can turn into nasty stuff that can kill you like phosgene or hydrogen chloride gas. It’s better to use a wire brush and acetone, carb cleaner, or dedicated degreasers from your welding supply shop and let evaporate thoroughly before welding.
There are different techniques...
There are different techniques when it comes to holding the nozzle, pushing or pulling the weld, or nozzle movement. The weld on the left was pushed left-to-right with the nozzle at the correct 45-degree angle. Pushing puts the shielding gas out in front of the weld, but can be harder to watch the puddle. The weld on right was pulled left-to-right and is a bit more even but if there were any impurities on the material, it could’ve contaminated the weld more easily. Either way, make a series of cursive-shaped “Es” starting at the bottom of the material and looping upwards: bottom-to-top. When working vertically, it’s always easier for the novice to start at the top and drag the weld downwards.