Gas welding is not the same as arc welding, although that latter equipment type does use inert shielding gases. More precisely, gas-fueled welding tools use combustible, free-floating substances to generate focused flames. This super-hot “torch” can easily melt and join solid metal workpieces. Interestingly enough, as documented in the following passages of text, there are several different types of gas welding.
Oxy-Acetylene Gas Welding
Two different gaseous mediums are channelled to the equipment’s handheld torch. Flammable acetylene fills one steel-cased cylinder. From the accompanying cylinder, oxygen feeds the burning gas flare. The two cylinders, regulators and hoses can be bulky. However, by delivering a dual-function mode, which means the torch can cut as well as it fuses, this gas welding technique easily makes up for that drawback.
Atomic Hydrogen Welding Benefits
Number one on the periodic table, hydrogen is an extremely flammable substance. Of some advantage here, water (H2O) is commonly used as a fuel source. That’s something of a hard to absorb fact, but it’s true. By using water electrolysis, the gaseous elements are extracted and separated. Oxyhydrogen torches, fueled by water electrolytes, are commonly used as jewellery making tools. Other applications include the curing of ceramics and the soldering of delicate electrical filaments.
Introducing MAPP Gas Cocktails
Methylacetylene-Propadiene-Petroleum creates a gaseous mixture that ignites as a safer than acetylene flame. Curiously, the torch burns almost as hot as pure oxy-acetylene, but it contains a number of relatively inert components. Unfortunately, there’s hydrogen flowing in the mix, which makes the gaseous medium an unsuitable choice for steel fusing applications. Used on hot ferrous metals, hydrogen embrittlement is inevitable.
Low-Temperature Butane and Propane Welding
Relatively cooler than an oxy-acetylene rig, the torch temperature of a Butane flame still exceeds the 1300°C mark. Propane burns even hotter. Easy to transport, the two alkanes are usually reserved for use as brazing or soldering fuels. Cable heat shrinking, plumbing applications and more, the temperatures suit such applications, but they fall short of the white-hot temperatures required to weld or cut steel.
Some welding gas equipment rigs can even be used underwater. Once upon a time, oxy-acetylene cylinders were used below the waves to seal large pipes. However, the deeper the flame is used, the less effective the gases become, probably because of the increased pressure. Hydrogen welding combustibles are similarly affected by the deepwater pressures, which is why dry chamber welding and exotic exothermic rods are now standard. Still, the benefits of gas welding are clear for all to see. Indeed, many of these torches and cylinders can weld as well as they slice up solid steel.