A blowtorch, also referred to as a blowlamp, is an ambient air fuel-burning

gas lamp Gas lighting is the production of artificial light from combustion of a gaseous fuel, such as hydrogen, methane, carbon monoxide, propane, butane, acetylene, ethylene, coal gas (town gas) or natural gas. The light is produced either directly ...

used for applying

flame A flame (from Latin '' flamma'') is the visible, gaseous part of a fire. It is caused by a highly exothermic chemical reaction taking place in a thin zone. When flames are hot enough to have ionized gaseous components of sufficient density they ...

and

heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...

to various applications, usually

metalworking Metalworking is the process of shaping and reshaping metals to create useful objects, parts, assemblies, and large scale structures. As a term it covers a wide and diverse range of processes, skills, and tools for producing objects on every scal ...

. Early blowtorches used

liquid fuel Liquid fuels are combustible or energy-generating molecules that can be harnessed to create mechanical energy, usually producing kinetic energy; they also must take the shape of their container. It is the fumes of liquid fuels that are flammable ...

, carried in a refillable reservoir attached to the lamp. This is distinct from modern gas-fueled torches burning fuel such as a

butane torch A butane torch is a tool which creates an intensely hot flame using a fuel mixture of LPGs typically including some percentage of butane, a flammable gas. Consumer air butane torches are often claimed to develop flame temperatures up to appro ...

or a

propane torch A propane torch is a tool normally used for the application of flame or heat which uses propane, a hydrocarbon gas, for its fuel and ambient air as its combustion medium. Propane is one of a group of by-products of the natural gas and petroleum ...

. Their fuel reservoir is disposable or refillable by exchange. Liquid-fueled torches are pressurized by a piston hand pump, while gas torches are self-pressurized by the fuel evaporation. The term 'blowtorch' is commonly misused as a name for any metalworking torch but properly describes the pressurized liquid fuel torches that predate the common use of pressurized fuel gas cylinders. Torches are available in a vast range of size and output power. The term blowtorch applies to the obsolescent style of smaller liquid fuel torches. Blowtorches are typically a single hand-held unit, with their draught supplied by a natural draught of air and the liquid fuel pressurized initially by hand plunger pump, then by regenerative heating once the torch is in operating state. The larger torches may have a heavy fuel reservoir placed on the ground, connected by a hose. This is common for butane- or propane-fuelled gas torches, but also applies to the older, large liquid paraffin (kerosene) torches such as the

Wells light A Wells light was a large paraffin-fuelled (kerosene) blowlamp used for engineering work, particularly for illumination, in Victorian times. At a time before widespread electrical lighting, they were the most common form of high-powered portable il ...

. Many torches now use a hose-supplied gas feed, which is often mains gas. They may also have a

forced-air A forced-air central heating system is one which uses air as its heat transfer medium. These systems rely on ductwork, vents, and plenums as means of air distribution, separate from the actual heating and air conditioning systems. The return ...

supply, from either an air blower or an oxygen cylinder. Both of these larger and more powerful designs are less commonly described as blowtorches, while the term blowtorch is usually reserved for the smaller and less powerful self-contained torches. The archaic term "blowpipe" is sometimes still used in relation to

oxy-acetylene welding Principle of burn cutting Oxy-fuel welding (commonly called oxyacetylene welding, oxy welding, or gas welding in the United States) and oxy-fuel cutting are processes that use fuel gases (or liquid fuels such as gasoline or petrol, diesel, ...

torches.

History

The blowtorch is of ancient origin and was used as a tool by goldsmiths and silversmiths. They began literally as a "blown lamp", a wick

oil lamp An oil lamp is a lamp used to produce light continuously for a period of time using an oil-based fuel source. The use of oil lamps began thousands of years ago and continues to this day, although their use is less common in modern times. Th ...

with a mouth-blown tube alongside the flame. This type of lamp, with spirit fuel, continued to be in use for such small tasks into the late 20th century. In 1797 or 1799, German inventor August von Marquardt invented a blowtorch in

Eberswalde Eberswalde () is a major town and the administrative seat of the district Barnim in the German State ( Bundesland / ''federated state'') of Brandenburg, about 50 km northeast of Berlin. Population 42,144 (census in June 2005), geographi ...

. Another early blow pipe patent comes from USA, dated May 13, 1856. In 1882, a new vaporizing technique was developed by Carl Richard Nyberg in Sweden, and the year after, the production of the Nyberg blowtorch started. It was quickly copied or licensed by many other manufacturers. The US blowtorch was independently developed with a distinctive flared base and was fuelled by

gasoline Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organi ...

, whereas the European versions used

kerosene Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...

for safety and low cost. After the

Korean War , date = {{Ubl, 25 June 1950 – 27 July 1953 (''de facto'')({{Age in years, months, weeks and days, month1=6, day1=25, year1=1950, month2=7, day2=27, year2=1953), 25 June 1950 – present (''de jure'')({{Age in years, months, weeks a ...

in the 1950s, 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. There remain several manufacturers producing brass blowtorches in India, China and

North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and shares borders with China and Russia to the north, at the Yalu (Amnok) and T ...

for markets where propane gas is difficult to obtain or too expensive to be viable.

Applications

The blowtorch is commonly used where a

diffuse Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

(wide spread) high temperature naked flame heat is required but not so hot as to cause

combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combus ...

welding Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature techniques such as bra ...

. Temperature applications are

soldering Soldering (; ) is a process in which two or more items are joined by melting and putting a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoining metal. Unlike welding, soldering does not involv ...

brazing Brazing is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, with the filler metal having a lower melting point than the adjoining metal. Brazing differs from we ...

, softening paint for removal, melting roof

tar Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bi ...

, or pre-heating large

casting Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a ''casting'', which is ejected ...

s before

such as for repairing. It is also common for use in weed control by controlled burn methods and melting

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

and

ice Ice is water frozen into a solid state, typically forming at or below temperatures of 0 degrees Celsius or Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaqu ...

from pavements and

driveway A driveway (also called ''drive'' in UK English) is a type of private road for local access to one or a small group of structures, and is owned and maintained by an individual or group. Driveways rarely have traffic lights, but some that bear ...

s in cold climate areas. Especially the United States and Canada, road repair crews may use a blowtorch to heat

asphalt Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term ...

or bitumen for repairing cracks in preventive maintenance. It is also used in cooking; one common use is for the creation of the layer of hard caramelized sugar in a

crème brûlée ''Crème brûlée'' or ''crème brulée'' (; ), also known as burnt cream or Trinity cream, and virtually identical to the original crema catalana, is a dessert consisting of a rich custard base topped with a layer of hardened caramelized sugar ...

Types and variants

The blowtorch is referred to in industry and trade as per the fuel consumed by the tool: *Gas: ** propane gas, see

MAPP gas MAPP gas was a trademarked name, belonging to The Linde Group, a division of the former global chemical giant Union Carbide, for a fuel gas based on a stabilized mixture of methylacetylene (propyne), propadiene and propane. The name comes from ...

** butane gas, see

** liquefied petroleum gas (LPG) with ambient atmospheric air via a replaceable LPG cylinder. ** oxy-fuel torch *Liquid, with ambient atmospheric

air The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...

after vaporizing it using a coiled tube passing through the flame. They take time to start, needing pre-heating with burning

methylated spirit Denatured alcohol (also called methylated spirits in Australia, Canada, Ireland, New Zealand, South Africa, and the United Kingdom; wood spirit; and denatured rectified spirit) is ethanol that has additives to make it poisonous, bad-tasting, foul ...

: ** kerosene as per C.R. Nyberg patent of 1882: a simple

ing

torch A torch is a stick with combustible material at one end, which is ignited and used as a light source. Torches have been used throughout history, and are still used in processions, symbolic and religious events, and in juggling entertainment. I ...

using liquid fuel (such as

(USA) / paraffin oil (UK). **

diesel Diesel may refer to: * Diesel engine, an internal combustion engine where ignition is caused by compression * Diesel fuel, a liquid fuel used in diesel engines * Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...

biodiesel Biodiesel is a form of diesel fuel derived from plants or animals and consisting of long-chain fatty acid esters. It is typically made by chemically reacting lipids such as animal fat ( tallow), soybean oil, or some other vegetable oil ...

In the case of the gas torch the fuel tank often is small and serves also as the handle, and usually is refuelled by changing the fuel tank with the liquefied gas in it. The forms with gaseous fuel are sometimes fed from a

liquid petroleum gas Liquefied petroleum gas (LPG or LP gas) is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, propylene, butylene, isobutane and n-butane. LPG is used as a fuel gas in heating appliances, cooking ...

cylinder via a hose.

Variant

A flame gun is a large type of blowlamp with built-in fuel tank, used for various purposes: weed control by controlled burn methods, melting snow and ice off walk and driveways in the winter, starting a fire, etc. It is commonly confused in word usage with a flamethrower.

Media

Image:Small butane torch.jpg, A small

Image:Aa butaneblowlamp.jpg, Handheld butane blowtorch Image:Aa paraffin flamegun.jpg, Modern paraffin flame gun, 3 feet 3 inches = 1 m long File:Aa propaneblowlamp 00.jpg, Handheld propane blowtorch File:Construction of a crosswalk using polymer modified cement slurry.jpg, Large

used for construction

References

External links

Website with information about gasoline blowtorches

''Popular Mechanics'' October 1, 1926, pp 685. "Blowtorch Made from Gasoline Lamp" by LB Robbins

{{Authority control Gardening tools Burners Tools