Nepedia
Back to Discover
Advanced Reader
💻

Blowtorch

technology Maturity 11-13 Next article →

A blowtorch, sometimes called a blowlamp, is a tool used to apply a flame and heat to specific tasks.

Small butane torch
Small butane torch

It is most commonly used in metalworking, but it has many other uses. For example, chefs use small butane torches to melt sugar into a hard layer for crème brûlée.

Aa butaneblowlamp
Aa butaneblowlamp

While people often use the term "blowtorch" for any tool that makes a flame for metal, the name technically refers to a specific type of tool. Properly speaking, a blowtorch is a pressurized liquid fuel torch. These tools are vital because they provide a wide, high-temperature flame. This heat is strong, but it is usually not hot enough to cause combustion or welding.

There are two primary ways these tools function based on their fuel. Modern gas torches use fuels like butane or propane.

Aa propaneblowlamp 00
Aa propaneblowlamp 00

These tools are often self-pressurized. This means the fuel creates its own pressure as it evaporates into a gas. In many gas torches, the fuel tank is small and also acts as the handle. Users often refuel them by replacing the entire tank with a new one. Some larger gas torches are connected to a hose that leads to a larger liquefied petroleum gas (LPG) cylinder or even a mains gas supply.

Older, traditional blowtorches work differently by using liquid fuels. These include kerosene, diesel, or biodiesel.

Kerosene Blow Torch
Kerosene Blow Torch

To get the fuel to burn, it must undergo a process called vaporizing. This means the liquid must turn into a gas before it reaches the flame. In these tools, a coiled tube passes through the flame to heat the liquid. This heat turns the liquid fuel into gas. To start these torches, a user often needs to pre-heat them using methylated spirit. Early versions of these liquid torches required a piston hand pump to create the necessary pressure.

Liquid-fueled torches can be small, single handheld units. They use a natural draught of air to provide oxygen for the flame. In these models, a hand plunger pump provides the initial pressure. Once the torch is operating, regenerative heating helps maintain the pressure. However, larger liquid torches may be more complex. They might have a heavy fuel reservoir that sits on the ground. This reservoir is then connected to the torch by a hose. This setup is seen in large kerosene torches, such as the Wells light.

Aa paraffin flamegun
Aa paraffin flamegun

The history of these tools goes back to ancient times. Goldsmiths and silversmiths used very early versions. These started as a "blown lamp," which was a wick oil lamp with a tube for blowing air. In 1797, an inventor named August von Marquardt created a blowtorch in Eberswalde, Germany. Later, a patent for a blowpipe was filed in the United States on May 13, 1856. A major breakthrough occurred in 1882 when Carl Richard Nyberg developed a new vaporizing technique in Sweden. His design was so successful that production began in 1883, and many other companies copied or licensed his work.

Fuel choices often depended on where the tool was being used. In the United States, blowtorches were developed with a flared base and used gasoline. In Europe, manufacturers preferred kerosene because it was cheaper and safer.

Construction of a crosswalk using polymer modified cement slurry
Construction of a crosswalk using polymer modified cement slurry

This changed after the Korean War in the 1950s. During this time, propane became much more available worldwide. By the 1970s, most companies that made the old gasoline or kerosene torches had disappeared. Today, brass blowtorches are still produced in India, China, and North Korea. These markets still use them because propane gas can be difficult or expensive to find there.

Blowtorches are used for many practical jobs in the world. In construction and maintenance, they are used for soldering and brazing. They can also soften paint so it can be removed or melt roof tar.

Soudogaz X2000
Soudogaz X2000

In cold climates, people use them to melt snow and ice from driveways and pavements. Road crews in the US and Canada use them to heat asphalt or bitumen to repair cracks. They are even used for weed control through controlled burning. A large version of this tool is called a flame gun. It has a built-in fuel tank and is used for big tasks. While some people confuse flame guns with flamethrowers, they are different tools used for different purposes.

705 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (7)
File:Soudogaz X2000.JPG
Soudogaz X2000.JPG
File:Construction of a crosswalk using polymer modified cement slurry.jpg
Construction of a crosswalk using polymer...
File:Small butane torch.jpg
Small butane torch.jpg
File:Aa butaneblowlamp.jpg
Aa butaneblowlamp.jpg
File:Aa paraffin flamegun.jpg
Aa paraffin flamegun.jpg
File:Kerosene Blow Torch.jpg
Kerosene Blow Torch.jpg
File:Aa propaneblowlamp 00.jpg
Aa propaneblowlamp 00.jpg
More to explore

🔗 What's this?

Concepts mentioned in this article

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.