Mig mag welders are a form of gas metal arc welding equipment. Mig stands for metal inert gas. Mag stands for metal active gas. Mig mag welders are actually two different types of welder that have been misnomered into one.
Gas metal arc welding was originally developed for welding aluminium and other non-ferrous metals. It spread into the steel industry because it is a faster method of welding. Unfortunately, inert gasses are expensive and this limited the use of mig mag welders in smaller steel working workshops. Gas welding is now mostly done with semi-inert gasses like carbon dioxide. But it has not faded into obscurity.
Because mig mag welders do not require or even use a shielding gas, it is not often used outside or in areas where the air flow may suddenly change.
The operation of mig mag welders is not too complicated when working with basic metals like steel. The weld quality will always fluctuate since the quality of the weld is dependent, not only on the experience of the person doing the welding, but on the environmental conditions as well. The trick to a good weld is to keep the process consistent and precise. This obviously becomes easier with practice, but practice can be expensive. If certain parameters are not observed, gas and electrodes may be wasted and they are expensive to replace. The more ferrous a metal, the more difficult it is to keep the weld from becoming porous. This happens when a metal cools faster than gas bubbles created in the welding process can escape. It can help to weld at a slower rate if you are working with a metal like aluminium which cools very quickly.
As with all welding, it is important to have the correct protective clothing in place when operating mig mag welders. The appropriate clothing includes heavy leather gloves and protective jacket sleeves as well as protective eye wear. A condition called arc eye is a common affliction of mig mag welders who do not wear the appropriate eye protection. It is caused by the ultraviolet light that is emitted when welding is done and causes the cornea of the eye to become inflamed, and in extreme cases, the retina may become burned. Curtains made of pvc can be put in place to protect the other people in the room form the ultraviolet light emitted by the welding process. Another thing to bear in mind is that you are working with a dangerous gas. It is important to make sure that there is enough ventilation in the area you are working in.