A High Speed Option to Ultra Slow TIG
Traditionally, GTAW lends itself well to the welding of thin gauge aluminum. On AC polarity, the operator easily strikes a balance between oxide surface cleaning and penetration. Second, the operator controls heat input using a remote foot or hand rheostat. Finally, the operator deposits an aesthetically pleasing “stacked dimes” bead. I want to make a case for an alternative process, sequential pulsed MIG.
But even with these characteristics, TIG remains a painfully slow method of moving from point A to point B. Because TIG is such a slow method, TIG becomes an expensive process from a labor cost standpoint. Additionally, qualified aluminum TIG welders have become increasingly difficult to find due to the high level of operator skill required. This is where sequential pulsed MIG comes into play.
Enter Sequential Pulse Technology for Aluminum
These inverter based power sources produce low heat input stringer beads for all position welding. For example, Lincoln has the “Pulse-on-Pulse” and Miller has the “Profile Pulse.” However, Lincoln’s technology only utilizes an energy pulse whereas Miller’s combines an energy pulse with a wire feed speed pulse.
As one pulse rapidly follows another pulse, the bead has a “ripple” that resembles a TIG weld. The difference is, the pulse technology produces a bead at travel speeds up to five times faster than TIG. The faster travel speed contributes to less heat input, distortion, and blow through. And since semiautomatic MIG doesn’t require the skill to coordinate the movement of a TIG torch in one hand and a filler rod in the other, operators are easier to find and train.
Author: Bob Page