Brazing torches are used to bond two pieces of metal together using temperatures 800 degrees Farenhiet (426 degrees Celsius) or greater. When using temperatures lower than this, it is usually considered soldering, not brazing. Brazing torches provide the flame or arc that melts the filler material used to bond pieces of metal together.
There are many types of brazing torches, but three of the more common varieties include methylacetylene-propadiene (MAPP) gas, oxy/acetylene, and tungsten inert gas (TIG). All of these achieve the same purpose — to weld metal together — but the temperatures at which they operate vary. Certain brazing jobs require specific temperatures, so not all brazing torches are created equally. The temperature required and the type of torch needed will be determined by types of metals that need to be bonded together and the relative thickness of those metals.
MAPP gas brazing torches are usually hand held wands with a small tank directly attached. The tank contains the gas mixture. MAPP torches are used when welding light gauge material using a lower melting temperature filler, such as silver, lead, and brass alloys. Many welders consider using MAPP torches to be a form of soldering, not welding, as a result of these low temperatures.
Oxy/acetylene torches are the most common type of brazing torch and are often the most economical to operate. Oxy/acetylene brazing torches are among the most versatile and are usually the type found in home garages. These torches require the use of a tank of oxygen gas and a tank of acetylene gas connected to the torch head via hoses and pressure regulators. Oxy/acetylene torch heads consist of the body and interchangeable tip, which are swapped out based on heat requirements.
TIG torches use electricity to create an arc with a mixture of inert gas surrounding the arc to keep out impurities. TIG torches are operated by pressing a foot petal. The foot petal controls the amount of amperage which translates to heat energy. TIG torches resemble a fountain pen with a handle that houses the tungsten rod.
All types of brazing torches need to filler material to function properly. When operating these torches, welders hold the torch in one hand while feeding in the filler material with the other. All brazing torches can be dangerous if misused, and proper eye protection and clothing should be warn when operating them.