Arc Strike Methods: Scratch Start vs Lift TIG

What is an arc strike method?

In TIG welding, the arc must start between the tungsten electrode and the metal you are welding. The way that arc is initiated is called the arc strike method. Different welders use different methods, and the method affects how you begin each weld.

The three common methods are scratch start, lift start, and high frequency (HF) start. Each has a different way of creating the arc, and each appears on welder listings in different ways. Knowing what these words mean helps you read a listing and choose a machine that fits your experience level. For a closer look at one of these methods, see how high frequency start works.

Scratch start: the basic method

Scratch start is the simplest arc strike method. You touch the tungsten to the workpiece and drag it across the surface, like striking a match. The contact creates a spark, and the arc begins. This method is often found on basic stick welders that also offer DC TIG.

Scratch start does not require any extra electronics. It works on any machine that can produce a DC welding current. However, dragging the tungsten across the metal can leave marks on the workpiece and can contaminate the tungsten tip, especially if you touch it to the metal while it is hot. The difference between scratch and lift start is explained in lift start versus scratch start.

For a beginner, scratch start can be tricky because you need to lift the tungsten away at the right moment. If you lift too soon, the arc stops; if you lift too late, the tungsten sticks to the metal. It takes practice to get a clean start.

Lift start: a controlled touch

Lift start is a refinement of scratch start. You touch the tungsten to the workpiece, then lift it away slowly. The machine senses the contact and provides a low current to start the arc as you lift. This reduces the spark and the risk of contaminating the tungsten.

Lift start is often described as a beginner-friendly method because it does not require the dragging motion of scratch start. You simply touch and lift. Many dual-voltage stick welders and some DC TIG machines list lift TIG as a feature. If you are looking for a machine with this feature, check the best TIG welders for options.

Lift start still requires the tungsten to touch the metal, so it is not completely contact-free. But it is gentler on the tungsten and the workpiece compared to scratch start. For a first TIG machine, lift start can be a good choice if you are learning the basics.

High frequency start: no contact needed

High frequency (HF) start uses a high-voltage, high-frequency spark to ionize the gap between the tungsten and the workpiece, starting the arc without touching the metal. This is the method used on many AC/DC TIG welders, especially those designed for aluminum.

HF start is often listed on a welder title as 'HF start' or 'high frequency start.' It is common on machines that offer AC TIG, because AC welding is often used for aluminum, and a non-contact start helps avoid contaminating the tungsten. For aluminum projects, the best welder for aluminum guide can help you find a machine with this feature.

For a beginner, HF start can be easier because you do not have to coordinate the touch and lift. You position the tungsten close to the metal and press the foot pedal or torch switch. The arc starts cleanly. However, HF start adds complexity and cost to the machine, so it is more common on higher-tier TIG welders.

Which method is easier for beginners?

For a beginner, lift start is often the easiest to learn. It avoids the dragging motion of scratch start, which can be awkward, and it does not require the extra cost of HF start. Many entry-level TIG welders, including some stick/TIG combos, offer lift TIG. See our best TIG welders for machines that list this feature.

HF start is also beginner-friendly because it removes the need for contact altogether. If you are buying a machine for aluminum welding, you will likely need AC TIG, and most AC TIG machines use HF start. In that case, HF start is the practical choice.

Scratch start is the least forgiving for a beginner. It takes practice to avoid sticking the tungsten or leaving marks. If you are on a tight budget and only need DC TIG on steel, a scratch start machine can work, but expect a learning curve.

What to look for on a welder listing

When you read a welder listing, look for the arc strike method in the title or the bullet list. Common phrases include 'Lift TIG,' 'HF start,' or 'Scratch start.' Some listings may not state the method at all, which can be a sign that the machine uses scratch start. You can compare stated details in the best stick welders guide to see how these features appear.

If a listing says 'DC TIG' but does not mention lift or HF, it likely uses scratch start. If it says 'Lift TIG,' you know the machine has the controlled touch method. If it says 'AC/DC TIG' or 'HF start,' you can expect a non-contact start. For a deeper comparison of the two methods, see lift start versus scratch start.

The arc strike method is one detail among many. Consider it together with the input voltage, amperage range, and whether the machine is multi-process. A machine with lift TIG and dual voltage might be a better fit for a home garage than a scratch start machine with a single voltage. Our best dual voltage welders guide can help you find such a machine.

Questions to ask the maker

Before you buy, you can ask the maker or seller about the arc strike method. Questions like 'Does this welder use lift start or HF start for TIG?' or 'Is the TIG function scratch start only?' can clarify what the listing does not state.

You can also ask about the included torch and whether a foot pedal is included, since a foot pedal can make HF start easier to control. The maker's manual will describe the arc start procedure, so check that before you decide. If you are considering a multi-process machine, the best multi-process welders guide shows how arc start features vary across models.

Remember that the arc strike method is not a measure of weld quality. It is a feature that affects how you start each weld. Choose the method that matches your comfort level and the projects you plan to do.

What to pick for your situation

Questions

Is scratch start the same as lift start?

No. Scratch start requires dragging the tungsten across the metal to start the arc, while lift start uses a controlled touch and lift with a low current. Lift start is gentler on the tungsten and workpiece.

Do all TIG welders use high frequency start?

No. Many entry-level DC TIG welders use scratch start or lift start. High frequency start is more common on AC/DC TIG welders, especially those designed for aluminum welding.

Can I use lift TIG on aluminum?

Lift TIG is typically used on DC TIG welders, which are not ideal for aluminum. Aluminum usually requires AC TIG, which is often paired with high frequency start. Check the welder's specifications for AC output.

Does the arc strike method affect weld quality?

The arc strike method affects how the arc starts, not the quality of the weld itself. A clean start can help avoid tungsten contamination, but the weld quality depends on your technique and settings.