In MIG/MAG welding, the welder’s tool is a welding gun. It is used to introduce the filler material wire, shielding gas and the required welding current to the work piece. The most important issues related to MIG/MAG welding are the welding position, welding gun angle, wire stick out length, welding speed and the shape of the molten weld pool.
The arc is ignited with a trigger in the gun, and the gun is then moved at a steady welding speed along the weld groove. The formation of the molten weld must be observed. The position and distance of the welding gun relative to the work piece must be maintained constant.
It is particularly important that the welder concentrate on managing the molten weld at all times. A moment of wandering thoughts increases the risk of welding errors. In such cases, it is advisable to interrupt the welding for a moment and then resume.
- the sound of the arc is loud
- there is a lot of spatters
- the weld is more narrow and the cap is higher
The arc voltage is too high in relation to the wire feed speed, if
- the sound of the arc is soft
- the arc is long
- the weld is wider and lower
- the drop size of the filler material is large
- the risk of undercuts is increased
There are a number of tables and guides that will assist in producing good welding results. There are also welding machines that automatically determine the correct arc voltage for the wire speed and welding current. Even in those machines, one may need to make adjustments to the arc voltage, as there may be differences between the filler material wires of different manufacturers.
With power sources equipped with stepped voltage adjustment it may not be possible to adjust the voltage to the exact correct figure in relation to the wire speed. In such cases, one can do the fine-tuning by increasing or decreasing the speed of the wire feed.
Common tips for enhancing welding work
There are simple ways for enhancing the welding work. With manually done work stages planned in an appropriate way and designed ergonomically, individual production may experience higher productivity increases than mechanisation would attain.
Pay attention to the working position. The most efficient position to do welding is downhand. In downhand welding, the work piece is placed on a level so that welding can be done in a natural position. Devices intended for turning the work piece should be utilised so that the work piece position allows for an ergonomic welding position.
Choosing the right welding process also plays an important role in work productivity. Any productivity increase attained by changing the welding process should be carefully investigated, even if changing the process could require additional investments.
Correct choice of welding parameters affects the efficiency of the welding work and also extra labour expenses. For example, the time spent removing spatters decreases the productivity of welding work. One can reduce the generation of splashes with pulse welding, for example.