Blowtorches are typically a single, hand-held unit, with their draught (current of air) supplied by a natural draught of air and the liquid fuel pressurized initially by a hand plunger pump, then by regenerative heating (heat exchanger) once the torch is in operating state.
The blowtorch (blowlamp) is of ancient origin and was used as a tool by gold and silversmiths. They began literally as a “blown lamp”, a wick oil lamp with a mouth-blown tube alongside the flame. This type of lamp, with gasoline, alcohol, or kerosene fuel, continued to be in use for small tasks into the late 20th century.
The blowtorch is commonly used where a diffuse (wide spread) high temperature naked flame heat is required but not so hot as to cause combustion or welding. Temperature applications are soldering, brazing, softening paint for removal, melting roof tar, or pre-heating large castings before welding such as for repairing.
The blowtorch business remained strong through the Second World War, but changes in technology were ahead. The final demise, by 1970, of gasoline and kerosene torches came with the introduction of propane blowtorches in the 1950’s, coupled with the advent of plastic water pipes.
After the Korean War in the 1950s, wider availability of propane caused many changes in the blowtorch industry worldwide, and by the 1970s most manufacturers of the old type of blowtorch, using gasoline or kerosene as fuel, had disappeared.
Modern torch 2023