Arc Welding Equipment and Processes

The end goal for all arc welders is the same – an expertly welded, precision product that’s to standard, sturdy, and even beautiful. Getting there though can be vastly different depending on the type of arc welding process they employ. Today, there are five main welding styles, and each uses its own processes, equipment, and applications.

As you keep gaining experience and expertise in any style of arc welding, you’ll find that within each style lies a myriad of other choices, details, advice and tips for getting that perfect weld. But, as a wise woman once said, it’s always best to start at the beginning.

MIG/GMAW

What it means: Metal Inert Gas/Gas Metal Arc Welding

Process: MIG welding is all about consumables, starting with a constantly fed wire that runs through the welding gun at a steady pace. As it exits the gun, it comes into contact with an electrically charged tip that causes it to melt and create the weld puddle. Gas shields the weld, but the torch tip and other consumable parts melt during the process and need to be replaced at regular intervals.

Equipment: A MIG setup requires a constant-voltage (CV) power source, a wire-feeding system, ground clamp, torch, shielding gas, and consumables. It is one of the easiest processes to master — simply pull the trigger to start and stop the weld — but it’s also one of the most prone to troubleshooting issues because of all the moving parts. Precision settings and regular maintenance are essential.

TIG/GTAW

What it means: Tungsten Inert Gas/Gas Tungsten Arc Welding

Process: What’s the difference between TIG and MIG welding? While MIG welding uses a continuous wire feed, TIG uses non-consumable tungsten welding rods to generate extreme heat and melt the metal. Then, air or water cools it down and the welder uses a separate filler metal to create the weld. It’s a clean, versatile process that requires the most skill.

Equipment: A TIG arc welding equipment setup requires a constant current (CC) power source, ground clamp, torch, and filler metal. You’ll also need shielding gas, but different gasses are used for TIG vs. MIG welding equipment.

Flux/FCAW

What it means: Flux Cored Arc Welding

Process: FCAW welding is very similar to MIG welding in that it also uses a continuous wire feed and a charged tip to create welds. The difference between MIG and FCAW welding is the type of wire and the shield of the electrodes. While MIG welding uses gas for shielding, FCAW — just as it’s named — uses a hollow-core wire filled with flux. (Somewhat similar to a Pixy Stix candy.) In some cases, extra gas isn’t required, and this is better for outdoor work. It’s highly productive and is used most often in pressure vessels and heavy equipment.

Equipment: The arc welding equipment list is also similar to MIG — CV power supply, wire-feeding system and a water or air-cooled torch. In fact, many high-end MIG systems can support FCAW welding. But, keep in mind that it has a much higher deposition rate than MIG. So, it’s important that you select a setup that can keep up. We recommend fume extraction commitment since FCAW typically generates more smoke.

Plasma Welding/PAW

What it means: Plasma Arc Welding

Process: Plasma welding joins workpieces using a high-heat jet of ionized gas that is heated to plasma inside the torch and then forced out through a constricting nozzle. It generates an extremely focused and intense plasma jet that can make deep, narrow cuts in quick order. Primarily, automated applications utilize plasma welding.

Equipment: A plasma welding setup resembles that of a TIG, with a CC power source, tungsten-rod electrodes, and a ground clamp to complete the circuit. The big difference is the torch — it’s much more complicated than the TIG torch and requires a constant water feed for cooling. It utilizes a pilot arc to pre-heat the tungsten, which reduces tungsten micro-cracking. It also requires eagle-eye maintenance due to the extremely high-heat environment.

Stick Welding/SMAW

What it means: Shielded Metal Arc Welding

Process: Stick welding is one of the most widely used welding processes because of cost and versatility. It creates a weld by passing an electric current through a flux-coated electrode (the opposite of FCAW). This is referred to as “shielded” metal arc welding because the flux coating creates a cloud of gas that shields the metal as it melts and prevents oxidation. As the gas evaporates, it leaves behind slag. Then, the welder  scrapes it off at the end of the job.

Equipment: Stick arc welding equipment is so popular because of its inexpensive, simple and versatile setup. It requires a constant-current (CC) power supply, ground clamp, electrode holder, and electrodes. The types of electrodes are as varied as the metals they work best on, so be sure to do your research in advance.