Oxy-Acetylene Welding is the welding process of heating two pieces of metal to the melting point, bringing the parts together and while still in a molten stage hammered together to form a joint. Learning how to weld using this process will give a complete overview of welding.
The Oxy-Acetylene Welding process requires the use of a special welding torch that mixes oxygen and acetylene gasses that can produce a small intense flame heat of up to 6300 degrees. This temperature is more than twice the melting point of most metals.
This process has been widely used in the past for the manufacture of wrought iron projects such as iron gates and fences. These methods have widely been superseded by the introduction of electric arc welding.
Today Oxy acetylene welding is generally restricted to industries that work with copper pipe and the joining of copper and brass. Other specialized applications include as building up of brass wear plates and the welding of cast iron housings that may be cracked using brass or bronze rods as a filler.
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Oxy-Acetylene Welding Techniques
Check out this video showing how to create superior welds using oxy acetylene welding.
Gas Cutting Using Oxy-Acetylene.
Most gas torches include a function for gas cutting. This is in the form of a lever-style valve that allows an extra burst of oxygen through the cutting torch to the work that has been heated to the melting point.
This injection of oxygen to the work causes the parent metal to burn away with great force and speed, producing a small narrow cut in the metal.
Using this method has allowed metals to be cut easily either manually or by machines called profile cutters. Gas cutting manually can easily cut metals of 1/16 of an inch and up to two inches whereas profile cutting can cut steels up to four inches thick.
Many profile cutting machines now use LPG gas instead of acetylene as the flame and cut produced is cleaner. Propane torches for auto and manual cutting are constructed differently to acetylene torches and also require different cutting tips
Oxy Acetylene Welding Rods and Filler Rods
When choosing a welding filler rod try to avoid buying inferior quality as the better your grade of material in the welding rod the better the end result will be.
Your welding filler rod is used to lay over additional metal to the weld therefore it needs to match the parent metal. If the metals are dissimilar then best efforts to locate a filler rod comprising of a composition of the two metals. For example, if welding manganese or nickel-specific welding rods of specific alloys are recommended.
Welding wire and Oxy-Acetylene Welding rods are most always of Norway steel. This grade is most pure and gives a sound soft weld especially suited to machining if required. When welding aluminum the proper rod is most important as aluminum is difficult to weld and requires alloyed rods to ensure even flowing.
Why is Acetylene used for welding?
Welding has been widely used in many manufacturing industries. It is possible to do various welding procedures. Among the most popular types in this area is gas welding. It is mainly used for welding in a gas-fueled process by burning hydrogen or propane. Often the substitution of acetic acid with hydrogen butane or propane can also be made. Since the beginning of the 20th century, a metal cutting process combines oxygen with acetylene with cutting material. During the past decade, Acetylene has been recognized as a safe and powerful welding gas. However, there is increasing misinformation regarding whether or not propane is more efficient in welding as opposed to acetylene.
Oxy-Acetylene Welding Equipment
The equipment used to make Oxy-Fuel welding is comparatively small in cost, typically mobile, and versatile enough for several other related operations, including heat, bending and aligning of metals, pre-warm, post-heat, weld metals, and surface braze welding and torch brazing.
The basic setup is the welding torch itself, hoses, and pressure gauges for an oxygen and acetylene supply. In general, the gas supply is via large refillable gas bottles, usually placed on a mobile carriage for easy relocation as the bottles are very heavy. In some industrial workshops, the gas supply is piped to various work stations where the gas supply hoses are simply plugged in, making a more efficient working environment.
It is possible to perform automatic and mechanized oxygen cutting operations using a relatively small change of equipment. Metal normally bonded to Oxygen Fuels is carbon steel, a particularly low alloy, and most non-ferrous metal. The technique has generally never commenced in the welding of refractory and reactive metals.
Oxygen and acetylene gases are easily available. It includes oxygen and acetylene gas stored in metal tanks. The cylinders feature a regulator and flexible hose leading to the blower. Specially constructed safety systems include flame trappers between the hose and regulator. Fire traps protect against flashback fires from entering cylinders.
Types of Flames in Oxy-Acetylene Welding
Three different flames are employed: neutralization, oxidizing, and carburization. Welding usually takes place using a neutral flame set having equal amounts of oxygen and acetylene. The oxidized flame can be achieved by increasing only the oxygen flow and the carburizing flame can be achieved by increasing the acetylene flows in relation to oxygen flows. Because the metal is melted at temperatures over 1700deg. It is the only gas mixture that has sufficient heating to weld steel.
Oxyfuel welding rods
The welding filler rod that melts into welded joints is crucial to the quality of the finished welding. A good welding rod is designed to allow freely flowing metals that can be easily welded together to produce clean welding of the proper composition. The Weld filler rod can be used on different steels for hard surface applications and they can be manufactured in stainless steel.
Tip Size and Style
Steel sections have the same tip dimensions, giving the most cost-efficient use of a particular fuel for a specific fuel. All OFW gasoline should be consumed at any given time. But if burned, the fuel could be overheated or burnt off the tip and possibly cause damage to the cut. MAPP gas can’t perform well on most acetylene tips because their reheating ovens don’t have enough room. When using MAPP gas on a propane tip it may cause excessive overheating. The Tips are also available for flashbacks. A gastip is a natural gas that is easily removed by removing skirts from MAPP gas.
The difference between Oxy-Acetylene welding and other welding types?
Typically the SMAW, GMAW, or GTAW type is a heat source compared with oxyfuel welding. Oxyfuel welding uses the power of an air flame that has reached temperatures of more than 1,000 F. The oxyfuel welding method was employed at the early stages for welding thick plates. It is used mostly now for special welding applications such as braizing. Commonly used in the plumbing and refrigeration maintenance industry.
Arc welding is powered by electrical energy as the heat source, reaching around 1000 degrees Fahrenheit. The use of electrical welding is now the mainstream welding application.
How does Oxy-Acetylene welding work?
Oxy-acetylene welding enables the combustion of high energy, high temperatures, and fuel gases (the most common of them being acetylenes) in pure oxygen. It is then burned with the filling tube with an oxy-fuel gas mixture through the tip of a welding torch. Fuel and oxygen gas are kept in pressurized steel tanks. The regulator reduces gas pressure inside the tank. Gas flow is controlled via a flexible hose by a welder. Afterward, fillers are formed with bases. However, the melting and fusing of two metal pieces can also take place without using any filler materials.
What is Oxyacetylene?
Oxyacetylene is a volatile combination of pure nitrogen and acetone gases. The two gases are not chemically coupled whereas merely a mixture made only for a purpose – superheating. It may explode depending on the oxygen levels involved in the mixture. The resulting combustion can, however, produce heat and light when a given proportion has its correct balance.