Expecting it’s going to be easy as pie, you walk into shop armed with steel and a torch. At first, it isn’t. There’s a smell like burning metal and ozone, and then there’s that arc creating a blinding light, both exciting and terrifying. Your first instinct is that pushing the button will cause metal to stick. Rarely is this true on the first attempt. Controlling the flow, the penetration, and heat are keys to making a good weld vs a bad one.
Having a place to go back to in order to check your process settings is key. No need to remember all the numbers but if the weld pool starts acting funny you’ll want to know where to look. The four major processes can be considered tools, too. Wind, dirty steel? Stick welding will get the job done. Difficult conditions calls for stick welding. Indoors? Need speed and forgiveness as you learn? Use MIG welding. Use TIG welding for precision work that calls for a steady hand and clean welds. Want MIG’s speed plus stick’s toughness outdoors? Try flux-cored welding.
How to Set Up Your Welding Machine
See the chart showing which process to use in various environments and at what thicknesses. That keeps you from attempting to TIG weld a rusty old tractor frame in the rain. Once you choose a process, you have to get machine dialed in. I know guys who guess at the amperage and then ask why wire doesn’t stick or burns.
A general rule on TIG steel is one amp for every thousandth of an inch of material thickness. That’s your start. With MIG it’s more about the wire feed speed and voltage. Out of synch and arc will sputter and scream. And the visual guide is for the gas mixture used. Argon alone won’t help much for mild steel MIG. Use pure carbon dioxide and you’ll get a spattered bead even though it may be a strong weld.
The gas flow is important too. Not enough flow and you get porosity. Porosity are little holes that destroy strength. Too much flow and you waste money and create turbulent air flow.
Gravity wants to keep the puddle in place. It’s easy to weld flat, physics fights welding overhead. Adjustments account for position as shown on chart. Moving vertically and overhead often requires decreasing amps. This controls amount of liquid to prevent it from dripping onto your gloves.
Polarity makes a big difference. Using direct current with a positive electrode puts more heat into workpiece. That increases penetration in both MIG and stick. Electrode negative with direct current holds heat at the electrode. That’s cleaner for TIG on steel. Get this one wrong, and electrode melts before base metal does.
Welding is a process as much as it’s a checklist. Safety involves more than just your eyes, as UV radiation can damage them in seconds if your helmet lens isn’t shaded to match your amperage, and you absolutely need ventilation because breathing in fumes is asking for trouble later. A darker lens means higher amps and brighter arc. Inhaling the fumes will give you trouble later. Get some ventilation.
Welders settings is only guidelines…not laws. Weather conditions, joint fit and metal condition alter the weld behavior. Practice on scrap material before committing to job. The chart is a map….you still gotta drive the dang truck. That first good looking clean bead is magic…it’s actualy physics combined with patience.
