The 10 Best Cutting Torch Kits
The Vast Power Of Flame
The early forge welders used partially smelted iron ore heated in simple furnaces and then hammered together.
Using the proper tips, they can burn through metal as thick as eight inches or more using pressurized oxidation.
Humans have been using heat to join metal since ancient times. In the Iron Age, metalworkers widely adopted the earliest welding practices. The early forge welders used partially smelted iron ore heated in simple furnaces and then hammered together. In the last century, technology has advanced the field of metalworking just like it has many areas. Now even the home artisan can easily join together a wide range of metals at temperatures reaching thousands of degrees.
Blazing-hot temperatures at one's fingertips have a number of useful applications. A typical oxy-acetylene setup produces a flame as hot as 6,000 degrees Fahrenheit. Military, industrial, and artistic outfits have used these systems for decades, manufacturing durable and expressive pieces. The ability to chemically rip through hardened alloys makes demolition and salvage jobs easy when they might otherwise be impossible. The relative portability of a gas torch lets field operators use these tools in place of bulky angle grinders and welding generators.
Since all they do is burn two gasses, oxy-fuel torches are among the simplest and most versatile tools in the garage. Using the proper tips, they can burn through metal as thick as eight inches or more using pressurized oxidation. With proper care, they're a safe and straightforward way for skilled metalworkers and artists to manipulate steel and other alloys.
What Happens When The Torch Is Lit
A simple blowtorch uses a bottle of pressurized gas and ignites it as it mixes with atmospheric oxygen. That will only get your flame up to around 3,500 degrees. Cutting torches differ in one crucial way. In addition to the pressurized fuel, an additional tank of pressurized oxygen is fed to the nozzle. This allows for the efficient burning of fuel gasses even more volatile than propane.
This allows for the efficient burning of fuel gasses even more volatile than propane.
The process isn't too complex. Equal-length hoses feed pressurized fuel and oxygen to a nozzle with a pressure regulator. For welding purposes, the fuels burn together in order to bring both metal pieces to the same high temperature. When they're pressed together, the opposing metal molecules diffuse around each other, forming a metallic bond. Under the right conditions, this bond can be even stronger than the individual metals themselves — in poor welds, the bonds are often weaker.
When cutting metal, the fuel gas is used alone to heat the metal past its ignition point. Pressurized oxygen is applied, turning the burning iron into iron oxide. This melts away at half the temperature of iron, leaving a quick and clean incision.
There have been a few different fuels used in cutting torches in the last few decades. Gasoline, propylene, and MAPP Gas have mostly lost favor. Pure hydrogen is a useful fuel, particularly because it works at extremely high pressures and is therefore useful underwater. Because the main byproduct of burning hydrogen and oxygen is water, it's perfect for sensitive processes that require the flame to be free of contaminants.
In addition to underwater (or bariatric) welding, oxyhydrogen is suitable for working with impurity-free laboratory equipment (especially glass components), as well as crafting high-value precious materials or heat-polishing of acrylic glass. However, it can't be used to weld ferrous alloys because residual hydrogen from the oxidation process can make the metal brittle.
The most popular choice for most home and professional users is acetylene, a simple chemical made up of two carbon and two oxygen atoms. It's not cheap, but it burns cleanly, is readily available in most countries, and the vast majority of torch options on the market are designed for it.
Also of important note is propane, usually mixed with butane. It's not ideal for welding, but thanks to its burning tendencies, it's great for heating and can cut faster than other fuels, though usually not as cleanly. Propane is cheaper and easier to transport than acetylene, and a lot of models easily convert to its use.
Isn't All That Heat And Pressure Dangerous?
Not if you're careful. Like many other highly effective tools today, these machines can cause disaster when used carelessly. But proper knowledge, technique, and respect make using these products perfectly safe.
The opposite can be true when using alternate fuel types; harsher fuels are less volatile but can release fumes corrosive to living tissue.
Following a few important rules helps keep everyone and their welding equipment from exploding. For starters, the acetylene itself isn't just collected in an empty metal tank. A solid absorbing material such as wood fibers or diatomaceous earth takes up much of the space in these special reservoirs. Because acetylene is extremely volatile under pressure, acetone is used as a solvent medium to safely store the gas in the empty space left in the container.
Because of this relatively complex storage method, acetylene canisters must always remain upright. Should you tip one over, simply make sure to store it upright for as long as it was on its side. This lets you safely use the unit after the fuel mixture settles back to the bottom of the tank.
There's also the matter of the order in which you turn on and off the gas nozzles. Always turn off the oxygen valve first when using an oxy-acetylene setup. This keeps the excess fuel from backfiring into the hose and building up carbon soot or, worse, mixing and igniting fuels inside or outside the supply lines. That could have deadly results. The opposite can be true when using alternate fuel types; harsher fuels are less volatile but can release fumes corrosive to living tissue. Consult your specific model's user manual for the proper order of operations.
Also, most advanced units today employ flashback arrestors to keep gasses in their supply hoses, preventing dangerous combustion. There are a few different styles of arrestors that prevent burnback of volatile fuels and cut off gas sources in the event of increased fuel temperatures or combustion shockwaves.
As long as you follow directions, wear the right goggles, and treat these tools with respect, you can cut and weld like a pro in total safety.