Welding Equipment and Applications
If you are toying with the idea of getting a welding device, you will be confronted by a whole host of questions and considerations when choosing the right one. To shed some more light on the matter, we have listed here the most commonly used welding methods and given a introduction to the wonderful world of welding.
Manual Arc Welding, or Electrode Welding
Manual arc welding is a very common form of welding among DIY enthusiasts because it is very cheap and versatile compared to the types. A welding transformer, available in different sizes, serves as the power source. Using a replaceable rod electrode, an electric arc is produced between the work piece and the electrode holder. This electric arc melts the workpiece at the weld point, and the rod electrode slowly burns off, releasing the filling material which bonds the components. The rod electrode has a coating which gives off a gas, protecting the weld point from contact with air, and thus from oxidation. After welding, the so‐called slag remains at the weld seam, which must be removed with a chipping hammer.
|Advantages of manual arc welding||Disadvantage of manual arc welding|
|Suitable for work outdoors and in the rain||Cannot weld alloyed steels such as stainless steel|
|Due to the slag, the workpiece cools relatively slowly and so does not tend to warp so much||Welding produces weld spatters and fumes which should not be inhaled|
|Suitable for non‐alloyed steels, such as structural steels||Ensure adequate ventilation|
Gas-shielded welding (MIG/MAG)
In gas‐shielded welding, a motor is used to feed a wire filler material from a roll through a hose to the welding gun. At the end of the welding gun is the contact tip, through which the wire is fed. At the same time, the shield gas flows through this component and passes through an outlet nozzle precisely to the weld site where it surrounds the weld. An electric arc is created between the work piece and the welding gun via this wire. The gas protects the weld site from contact with air, and so from detrimental oxygen. The gas is supplied from a gas cylinder, which can be rented from DIY stores or specialist shops with a deposit, and can be exchanged for filled cylinders.
The term MAG welding is short for Metal‐Active Gas welding. For example, the gas can be CO2 or a mixture of argon and CO2. The MAG welding process is suitable for unalloyed steels.
MIG welding is the abbreviation for Metal‐Inert Gas welding, for which pure argon is predominantly used. Non‐ferrous metals (NFM) can be welded with the MIG welding process.
|Advantages of gas‐shielded welding||Disadvantages of gas‐shielded welding|
|Cleaner than manual arc welding||High initial and operating costs|
|Avoids the constant replacement of the rod electrode||To switch from non‐alloyed steel to alloyed steel, you need another gas|
|Striking the electrical arc is very simple||Limited suitability for working in the open air|
|Welding thin sheets is quite straightforward||Requires absolutely still air|
|The shield gas is non-toxic||Not very well designed for mobile applications|
TIG welding stands for Tungsten Inert Gas welding, and the main difference with MIG welding described above is in the electrode. The electrode consists of tungsten and doesn’t burn away. The workpiece is melted with pinpoint accuracy and a filler material, if necessary, is fed in the form of a hand guided wire.
Argon is usually used as the shield gas. TIG welding equipment can generally be switched from DC to AC. Alloyed and non‐alloyed steels can be welded with DC current. In AC operation, even light metals such as aluminium can be welded, although this does require a certain amount of practice.
|Advantages of TIG Welding||Disadvantages of TIG Welding|
|It is a very clean welding technology||Needs more practice|
|All weldable materials can be welded by this method||High initial and operating costs|
Welding means the unseparable bonding of two components with the help of heat and / or pressure, with or without welding filler materials. Although there are countless types of welding techniques, here we listed the most common types which are practical for the DIY enthusiast. These include „manual arc welding“ and „gas‐shielded welding“.