MIG welding, also known as Gas Metal Arc Welding (GMAW), is a process that utilizes a continuously fed solid electrode, shielding gas from an externally supplied source, and electrical power to melt the electrode and deposit this molten material in the weld joint. The equipment used automatically regulates the electrical characteristics of the arc. The only manual controls required of the welder for semi-automatic operation are travel speed, travel direction and gun (torch) positioning. Given proper equipment settings, the power supply will provide the necessary amperage to melt the electrode at the rate required to maintain the pre-selected arc length (voltage).

Oxyacetylene welding. also known as Oxy-fuel Welding (OFW), includes any welding operation that uses combustion with oxygen as a heating medium. With this family of processes, the base metal and a filler rod are melted using a flame produced at the tip of a welding torch. Fuel gas and oxygen are combined in the proper proportions inside a mixing chamber in the torch. Molten metal from the plate edges and filler metal, if used, intermix in a common molten pool and join when cooling. Commonly-used gases include acetylene, propylene, propane and natural gas.

Stick Welding, also known as Shielded Metal Arc Welding (SMAW), the most widely used of the various arc welding processes, utilizes a fixed length electrode and an electric power source to join a variety of different metals. The core of the covered electrode consists of a solid metal rod that is surrounded by a covering of mineral compounds and metal powders mixed with a binding agent to help them adhere to the surface of the electrode.

TIG Welding, also known as Gas Tungsten Arc Welding (GTAW), is a process that joins metals by heating them with an arc between a tungsten electrode (non-consumable) and the work piece. The process is used with a shielding gas and may also be used with or without the addition of filler metal. The primary variables in TIG Welding are arc voltage (arc length), welding current, travel speed and shielding gas composition. The amount of energy the arc produces is proportional to the current and the voltage.