Many modern TIG welders are capable of performing what’s called pulse welding. This feature rapidly cycles the welding current between a high (peak) and low (background) amperage. This pulsing action gives the person welding better control over the heat input, which can be especially useful in certain welding scenarios.
Peak current is where the majority of the welding and fusion occurs. It provides the necessary energy to melt the base metal. The lower background current maintains the arc but reduces heat input to the material, allowing the puddle to cool slightly. The pulse frequency, measured in pulses per second (Hz), controls how often the welder switches between the peak and background current. Some machines allow adjustments to the pulse width (the time spent at peak current) and pulse frequency.
Pulsing the current reduces the overall heat input. This is especially helpful in preventing overheating or warping of thin or heat-sensitive materials like stainless steel or aluminum. Pulsing can help maintain a stable arc at lower overall heat levels. This improves weld bead consistency, especially in out-of-position welding. By minimizing the heat input, pulse welding can help prevent distortion in thin metal sections.
Welders can achieve deeper penetration with less total heat input by focusing the heat during the peak current and reducing it during the background current cycle. The pulse setting helps create more uniform and visually appealing welds. This is particularly valueable in industries where appearance is important, like aerospace, automotive, and artistic metalwork.
In this video, professional fabricator Vince at VC Metal Worx (now Keystone Met’l Co) demonstrates the process using Eastwood’s TIG 200 LCD welder. Watch as he compares pulse welding to the traditional non-pulse TIG welding technique on stainless steel tubing.
Is it possible to add a pulse feature to your older TIG 200 AC/DC welder. Is there any aftermarket pulse machines?