What you should know about aluminium welding
Aluminium welding differs significantly from all other welding methods.
Because the melting temperature of the light metal is at a relatively low 660°C, welding aluminium is much more difficult than melting other metals or alloys. In addition, aluminium has a very high thermal conductivity.
Therefore a lot of heat must be applied when welding aluminium. If you want to weld aluminium correctly and durably, you must also take into account the high thermal expansion of the metal.
The correct welding sequence must therefore be observed.
Otherwise tensions can occur in the component – and the workpiece can become unusable. It is particularly difficult to prevent gas inclusions in the melt and binding defects.
The oxide layer is another handicap that can be tripped over when welding aluminium. If you want to weld the aluminium workpiece without any defects, the coating must be well ground off before the joint is made.
However, if you observe some principles in this activity and use the correct methods, you can also weld aluminium correctly, like almost all metals.
Aluminium welding for do-it-yourselfers and craftsmen
Aluminium can also be welded efficiently at home or in your own workshop with the necessary equipment and training. If you use mobile shielding gas welding equipment for aluminium welding, you must also provide the appropriate gas mixture.
This is not comfortable and quite expensive. Mobile cored-wire welding machines are an advantage when working as a do-it-yourselfer or craftsman. Because the shielding gas is already contained in the wire, no additional substance needs to be added. These are available at relatively low prices in the trade.
The welding processes:
MAG welding came from the USA to Europe in 1948 after a short period of application. The method belongs to the welding processes with arc and inert gas.
MAG (Metal Active Gas) welding is suitable for joints in mechanical engineering or automotive engineering. The method can also be used to produce joints of unalloyed or low-alloy steels at home.
MAG welding also achieves high strength results when fusing with stainless and high-alloy steel. Argon or helium are mixed with oxygen or carbon dioxide and used as shielding gases for this welding process of aluminium.
A coiled metal welding wire runs through a gun or a feeding device and melts in an arc between the workpiece and the electrode.
MIG welding is one of the welding processes with inert gas for aluminium. In this method, MIG stands for metal inert gas. The abbreviation also explains the difference to the previous method.
The method is similar to MAG welding, but does not use active but only inert shielding gases (non-reactive noble gases). Helium, argon or a mixture of both noble gases protect the arc and the weld seam from atmospheric influences.
A further development of the two processes is CMT welding.
With this method you as a do-it-yourselfer or craftsman can firmly connect steel and aluminium.
The young welding process is one of the arc methods. Modern joining technology is increasingly meeting the growing demands of industrial production. Economy, reproducibility and process stability are the essential criteria here.
In addition to these methods, aluminium can also be welded using the TIG technique.
Alternating current provides the necessary energy for this process. The blunt electrode surrounds a nozzle. As in MIG welding, inert shielding gases are used.
The most common processes for aluminium welding in our own workshop
The basics of aluminium welding can be learned by anyone who has manual skills and a little patience.
Before you are motivated to complete your tasks with aluminium welding, you should know the advantages and disadvantages of the methods, which are suitable as a hobby welder in your garage, which has been converted into a welding station, or in the basement.
Many hobby welders prefer the method of cored wire welding. With a relatively inexpensive cored wire welding machine you can weld like with a shielded gas welding machine. These devices can also be used as mobile welding machines.
It is not necessary to carry a gas cylinder. Inside the wire there is a powder which is transformed into inert gas when work starts.
If you want to weld aluminium in high quality, the TIG process is almost a must. However, the equipment for home use is an expensive purchase. The process itself is difficult to master and requires good training.
For beginners and hobby welders, welding with shielding gas (cored wire welding) can be recommended. Various mobile devices are available on the market at relatively low prices.