Welding is the way that pieces of metal are permanently joined together. Almost everything around you was either welded or made by some piece of equipment that was welded. You know that stainless steel coffee pot? That was welded. Your car? That was welded, too. And while your work boots and utility gloves probably weren’t, you can safely bet they were made by machines that were.
There are several different types of welding, each used for a specific type of metal or seam. Every method uses different tools, equipment and techniques. Additionally, while there is a large variety of welding methods to choose from, there are four which are most commonly used.
1. SMAW: Shielded Metal Arc Welding
Shielded metal arc welding, frequently referred to as stick welding, is a very common and popular method of welding. It is typically used in construction, steel fabrication, pipeline work and for repairing heavy equipment. It is a type of arc welding, in which a lightning-bolt-like electric current runs between the electrode, or “welding rod” (the part you hold in your hand) and the substrate (the metal you are welding).
When stick welding, the welder uses a consumable electrode; that is, the welding rod itself melts, creating the weld. The electrodes have a flux core, which is a chemical cleaner. As the metal in the electrode melts, the flux prevents oxidation which can weaken the weld.
2. GMAW: Gas Metal Arc Welding
This type of welding—also called MIG (Metal Inert Gas) Welding—also uses a consumable electrode. However, in MIG welding, the electrode is a solid wire that is constantly fed through the welding gun. MIG welding machines are designed to accommodate varying sizes and gauges of these welding wires.
Instead of using flux to prevent oxidation and other metal-weakening agents, MIG welders use an inert gas, which is also run through the welding gun. This gas could be carbon dioxide, or a mix of carbon dioxide and argon. MIG welding may also result in fewer fumes than stick welding.
This type of welding is easy to learn and can be used on a wide range of metals. With the availability of portable MIG welders, Gas Metal Arc Welding has become much easier to bring to the location of the work needed.
3. FCAW: Flux Cored Arc Welding
Flux-cored Arc welding has all the speed of MIG welding, with the efficiency of Stick welding. Like with MIG welding, workers performing Flux Cored Arc Welding have a continuously fed wire running through the gun. However, this wire (the consumable electrode) has a flux core, just like the electrodes used in stick welding. This eliminates the need for the addition of inert gas that MIG welding requires.
This type of welding is preferred for its speed and higher electrode efficiency. There are many different kinds of electrodes available for this kind of welding. Most of these are either self-shielded or gas-shielded and come in an array of classifications. Before starting any Flux Cored Arc Welding project, make sure you check the different types of FCAW electrodes to make sure that you have the right one for your project.
4. GTAW: Gas Tungsten Arc Welding
This type of welding is known by several common names—TIG Welding, Heliarc Welding and Gas Tungsten Arc Welding. Unlike the other types of welding mentioned so far, this type does not use a consumable electrode. Instead, the welder uses an external rod to create the molten metal needed to forge the weld.
TIG welding is known for its strong, high-quality welds, though it does require a higher level of skill than other types of welding. The welds made from TIG welding also tend to be very clean and attractive to the eye. Gas Tungsten Arc Welding does require an inert gas shield which, for this type of welding, is usually argon or an argon mixture.
The Tools of the Trade
For any manual welding, you will need certain equipment to get the job done. You will need a welding machine; this produces the high electrical needs to create the arc that you ultimately weld with. You will need some type of electrode—either consumable or non. If you are not working with flux-cored electrodes, or if a shielding gas is required, you will need to supply an inert gas as well.
No matter which kind of welding you choose to perform, be sure you have the proper personal protection equipment at all times. This means wearing quality welders gloves and boots, flame-resistant clothing and most of all the right welding shield.