| Attribute | Lift Arc Start | Scratch Start |
|---|---|---|
| Ignition Method | Uses a low current to lift the tungsten electrode off the workpiece to create an arc. | Creates an arc by physically striking the tungsten electrode on the workpiece and pulling away. |
| Arc Control | Provides smooth arc initiation with minimal current surges. | Less control over arc initiation, leading to potential current surges. |
| Arc Stability | Produces a stable arc with minimal spatter, ideal for precision welding. | Arc stability can vary, often resulting in more spatter and inconsistent starts. |
| Contamination Risk | Minimal risk of contaminating the weld pool with tungsten or other materials, as the electrode does not touch the workpiece during ignition. | Higher risk of contamination, as the electrode touches the workpiece, potentially transferring impurities. |
| Ease of Use | Easier for beginners and reduces the chance of electrode sticking. | Requires more skill to control arc initiation without electrode sticking or causing contamination. |
| Electrode Wear | Reduces electrode wear and extends electrode life due to non-contact arc initiation. | Increases electrode wear as the electrode contacts the workpiece during ignition. |
| Weld Quality | Results in higher weld quality with fewer defects and minimal distortion. | May result in lower weld quality with increased chances of arc marks and surface defects. |
| Equipment Requirements | Requires a TIG welder with a lift arc start function, typically found in advanced or inverter-based models. | Can be performed with basic TIG equipment, no specialized settings required. |
| Heat Affected Zone (HAZ) | Smaller HAZ due to controlled arc initiation, reducing thermal distortion. | Larger HAZ due to uncontrolled arc initiation, causing increased thermal stress on the material. |
| Material Suitability | Ideal for thin materials and sensitive applications like stainless steel, aluminum, and titanium. | More suited for thicker materials where arc control is less critical. |
| Post-Weld Finishing | Minimal post-weld finishing required due to clean starts and reduced contamination. | Often requires additional finishing to remove arc marks or defects caused during arc initiation. |
| Environmental Impact | Lower environmental impact due to reduced tungsten contamination and material wastage. | Higher environmental impact due to increased tungsten wear and potential for rework. |
| Cost Efficiency | More cost-efficient in the long run due to reduced electrode wear and higher quality welds. | Lower initial cost but may lead to higher costs due to increased electrode usage and post-weld rework. |
| Safety | Safer process as it reduces the chances of arc flash and spatter during arc initiation. | Less safe as the sudden arc can cause spatter and increase the risk of burns or eye injury. |
Lift Arc Start offers better arc control, reduced contamination, and higher weld quality, while Scratch Start is more cost-effective for basic applications but requires greater skill and may compromise weld quality.