Welding is the process of fusing materials such as metals or thermoplastics in order to seamlessly join them. It might first appear to be quite a specialist skill, though the basics of welding are quite simple really. Welding is the application of heat to materials in order to essentially melt them together, and there are a few different ways to begin and control that melting process.

As technology has improved over the years, different welding processes have been invented and refined. It's a good idea to understand the basics of the current welding types in order to pick the appropriate one for your job.

Arc Welding

Arc welding is also simply referred to as Stick welding. This is the most basic of all welding types, though it still has a wide range of uses. The welding stick uses electric current to form an arc between it and the metals to be joined. Stick welding tends to be used on thicker metals as it can be exceptionally hot, and isn't considered to be particularly tidy. An arc welding machine can be bought for pretty cheap, and even the most basic of these will be capable of tackling most of the tasks that the home handyman may require it for.

MIG (Metal Inert Gas) Welding and MAG (Metal Active Gas) Welding

MIG and MAG welding are probably the most commonly used types of welding in automotive fabrication and bodywork. In these types of welding process, a shielding gas is used along a wire electrode that feeds from a spool when you pull the trigger on the welding gun. The wire carries a high current, which both heats up the two metals to be joined and melts to add to the weld pool as well, and the gas prevents contamination of the weld pool. A constant voltage and direct current power source is required for this method, with most lower cost machines able to run happily on standard home power supplies. The MIG process uses only inert gases such as Argon and Helium, and is primarily used to weld aluminium . MAG welding is essentially the same as MIG welding, with the exception of the type of gas mixture used. In MAG welding, there is generally a mixture of Argon and CO2, sometimes along with a percentage of Oxygen. This active shielding gas interacts with the weld pool to both shield it, and to control the temperature, penetration and the amount of splatter.

FCAW (Flux-Cored Arc Welding) - Gasless

As an alternative to shielded gas welding, Flux-cored Arc Welding was developed. This welding process is quite similar to MIG process, except for the fact that in FCAW a special tubular wire filled with flux is used and shielding gas is not always needed, depending on the filler. This type of welding is well-known for being extremely inexpensive and easy to learn and most MIG machines will have settings to facilitate it. However, the lack of shielding gas often contributes to a very messy weld, and so it has quite limited practical use in the automotive industry.

TIG (Tungsten Inert Gas) Welding

A non-consumable tungsten electrode is used in this type of welding process. This tungsten electrode is made use of to heat the base metal and create a molten weld puddle. A shielding gas is also applied, to prevent weld contamination. Generally, TIG welding is employed to carry out high-quality work when a superior standard finish is required, without making use of excessive clean up by sanding or grinding. It's considered to be the most advanced type, and often requires the most expensive equipment.

Gas welding / Oxy-Fuel welding

It's probably more common to see an Oxy-fuel torch used to cut metal rather than weld it, but it is possible to weld metals with the right type of torch. Oxy-Fuel welding used to be the most common type of welding, but it has long since been superseded by other types. Now Oxy-Acetylene torches can be occasionally seen in use when brazing things like copper or brass, but their use as welders is pretty rare.