Aluminium has a much higher electrical conductivity than steel. Due to this it is much more difficult to heat the wire during short-circuit by Ohm´s law (I²*R), to ionise the shielding gas and to strike the arc. Additionally the surface is covered with a hard and insulating Aluminium-oxide layer, which needs to be broken before short-circuit. This arc striking problem could be partially overcome with conventional powersources with specially designed choke coils only. Due to the advance of electronic powersources it has become possible to increase the ignition current sufficiently fast and to reach the process parameters quickly afterwards.

For some years arc ignition is possible by means of a retractable wire feed. With this system the wire is fed slowly to the work piece until short-circuit occurs. Then the wire is retracted a few millimetres and a low-power arc strikes. Successively the arc is brought to the proper process parameters quickly. This provides the opportunity of a spatter-free ignition within a short and precise time frame. This way of arc ignition is limited to a wire feeder in immediate proximity of the contact tip in order to move the wire as accurate as possible. This may lead to a heavier and bulkier torch with disadvantages with semiautomatic and automatic applications. Only recently robotic systems can provide such a feature. There the retracting movement is done by the robot and not the wire-feeder.