In joining metal to metal there are various arc welding techniques that you can use. These techniques include wire feed welding - otherwise known as flux cored, gasless, mag, or mig arc welding alongside stick welding, tig welding, spot welding, and gas welding. These types of arc welding are described below:
1. Wire feed welding
This technique is technically referred to as Gas Metal Arc Welding or GMAW in short. A more popular term for the technique is arc mig (metal inert gas) welding. The method involves the use of a gun or torch which is fitted with a trigger. Once depressed, a wire starts to emerge and it is what you are supposed to point at your welding target.
The wire produced is actually solid steel. When it reaches the electrically charged contact tip of the gun it is molten and thus forms a weld puddle. An inert gas also passes through the contact tip and ensures that the molten steel isn’t affected by atmospheric exposure.
2. Spot arc welding
Spot arc welding is used when sheets of metal less than 3mm in thickness have to be bonded together. The application of heat energy to the targeted surface is done precisely such that the other parts of the separate sheets are not affected.
In actual spot welding you have to place two copper alloy electrodes over the target spot where the two metal sheets are to be bonded. An electric current will then run through these electrodes thus completing the welding action. The resistance between the two electrodes determines the heat delivered to the target spot and for this the technique is also called resistance spot welding.
3. Gas arc welding
Gas arc welding is facilitated by the use of a combination of gases, commonly acetylene and oxygen. Acetylene is extremely flammable while oxygen is used to support burning or combustion at the required rates. These gases are stored in valve-locked pressure cylinders. You should always pay attention to the state of the valves as these cylinders can fly at great speed through the air when the compressed gas finds a way out.
The welding flame is lit using a flint lighter and then the cylinder valves are opened slowly – acetylene first and then oxygen next so as to make a neutral flame.
4. Stick arc welding
This is one of the more used arc welding techniques. It is technically known as Shielded Metal Arc Welding or SMAW. In this technique electrodes covered in flux are used. During welding this flux melts and forms slag and gas which protect the molten weld and the arc. The slag remains on the welded surface and must be scrapped off.
5. Tig arc welding
This technique is also known as Gas Tungsten Arc Welding or GTAW. It is a welding process of high quality and is normally used when precision welding is required. During the welding process the metal being welded and the tungsten electrode form an arc and the subsequent weld pool is protected by a gas. If the use of filler wire is required, its addition to the weld pool is done separately.