Tig welding with a positioner

This style of welding is typical for stainless steel in the ultra high vacuum industry. No filler wire or rod is used, there is a foot pedal for the welding torch and a foot pedal for the positioner/rotator. The tig torch provides the heat via electric arc and an inert gas to protect the molten metal puddle at the moment of melting and resolidifying. Pulses for the arc as well as amps are set by the welder, as well as speed of rotation and gas flow rate. I keep my arc about 1/16" or smaller at all times.