How The Wire Welder Works

Wire welding has now become the most popular method of welding; let’s find out why, how it works and what are the advantages it has introduced.

Origin and characteristics of MIG / MAG welding methods
Wire welding, also known as continuous wire welding, is a process that was developed during the Second World War, when the American aviation industry was looking for a way to further lighten aircraft cells and make them more performing and faster. .

A few years ago, in fact, the aeronautical aluminum alloy had been patented, which allowed to increase the structural resistance of the aircraft without affecting too much on the weight; the only problem was the steel rivets used to hold the various parts of the fuselage and wings together. The wire welding was therefore developed precisely to be able to assemble the planes without resorting to the use of hot rivets, drastically reducing the weight.

The advantages of wire welding

This was possible because the welds carried out with the continuous wire method under gas protection, simplified with the abbreviation MIG / MAG, were of higher quality than the electrode ones. In the latter, in fact, a greater quantity of slag is produced, which contaminates the welding pool, while in the wire ones the welding pool is protected by a gas which acts as an insulator; consequently MIG / MAG welds are much more efficient in terms of tightness and resistance to twisting.

A further advantage introduced by the MIG / MAG welding method is represented by the increase in reproducibility and productivity; since the wire is supplied in a continuous form, the work must not be interrupted often, as required by the electrode welding method, as the latter wears out and must be replaced very often.

As a consequence, starting from the years following the Second World War, the annual production of welds has been increasing exponentially, both due to the introduction of the new wire welding method and thanks to the reduction in the costs of electronic products, which in turn led to a reduction in the prices of welding systems, favoring their diffusion also in the artisan and hobby field as well as professional and industrial.

The MIG / MAG operating principle

In light of what we discussed in the previous paragraph, therefore, it is not difficult to understand why, among all the models currently on the market, the best-selling welding machine is the MIG / MAG, or wire welding machine as it is commonly called in the hobby field; but how does this type of welding machine work specifically? And above all, is it within the reach of a novice welder?

As mentioned before, from a purely economic point of view, wire welders are now easily accessible even for novice welders and for DIY enthusiasts; in terms of the expertise and skills required, however, they are quite different from electrode welders.

The abbreviations MIG and MAG, respectively, mean Metal-arc Inert Gas and Metal-arc Active Gas, that is, they describe an arc welding method in which the molten metal bath is protected by a gas hood, which can be inert or active depending on the type of wire coating. The latter replaces the electrode and the relative clamp, as it is delivered continuously by the welding machine, as soon as the operator activates the welding torch; this consists of a sort of torch from whose end the wire comes out.

The difficulties of the method

Depending on the type of welding machine and the economic range to which it belongs, the torch can be set up only for supplying the wire or composed in such a way as to also house the nozzle for emission of the protective gas, and therefore the relative connection for a cylinder of gas.

This particular type of wire welder, however, precisely due to the fact that it has to be connected to a gas cylinder as well as to the electrical network, is more difficult to manage and above all to transport, which is why it is mainly used in the professional field, such as fixed installation in mechanics and carpentry workshops and laboratories, and in the industrial sector within large construction sites.

The hobby-class wire welders, on the other hand, being cheaper, are usually equipped with torches that only have the functionality of the extrusion of the wire for welding, therefore the shielding gas must be added using the appropriate glass tubes that are available on the market. ; paradoxically, therefore, professional welders are easier to use because with one hand the operator approaches both the wire and the gas flow to the welding point.

On the other hand, in hobby-type wire welders, the operator is forced to use both hands, one to control the torch with the wire and the other to pour the gas onto the weld pool, bringing the end of the tube close to it. . Consequently, carrying out the operation in such a way as to strike the arc, but at the same time prevent the wire or the gas container from coming into contact with each other or with the weld pool, requires greater skill and coordination of the hands.

Home applications

Although the method is more complex and requires greater skill, wire welding has now also spread in the home, because once you have acquired the right dexterity, the results offered are superior in all respects. Furthermore, the further impetus to their diffusion is given by the greater use of new generation metal materials and alloys, such as aluminum for example.

Today it is possible to buy a good wire welder from 30 to 90 Ampere with a minimum cost of between 100 and 200 euros, while the price of a professional wire welder from 200 to 250 Ampere can range from about 1,000 to 1,500 euros, to depending on the model chosen.

The yield limitations imposed in the home do not affect the versatility of use of the welding system, which in addition to wire welding is often able to perform electrode welding as well, but by the installation power itself that does not allow to weld too thick metal pieces. On the other hand, however, hobby wire welding machines are ideal for welding metal sheets, profiles and metal tubes with a thickness of a few millimeters; therefore they have an excellent performance in repair work and in the creation of frames, supports, objects and even tools of various types.

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