Introducing HelioCut, high-quality affordable plasma cutting consumables.

TIG Welding: Scratch Start, Lift Start, or High-Frequency?

TIG Welding: Scratch Start, Lift Start, or High-Frequency?

When considering a TIG welding machine, the number of features, modes, and settings can be daunting. One of the most critical to understand, however, is the arc initiation method a machine is designed to utilize. These are the three types of arc starting methods:

The Scratch Start Method in TIG Welding

The scratch start method is the oldest, simplest, and most difficult to use. With the scratch start method, welders must manually “scratch” their electrode across the workpiece, similar to This Photo by Unknown Author is licensed under CC BY SA striking a match.

This is not very user-friendly and takes quite a bit of practice, as the electrode tends to stick to the workpiece, leading to point loss on the electrode and contamination of the weld. When using this method, the operator must also manually terminate the arc by pulling away from the workpiece. Gas is controlled by way of a valved torch head instead of being controlled by a gas solenoid in the machine. This arc starting method will only be found on older machines, entry-level machines, and machines converted from SMAW operation. If you are new to TIG welding, machines utilizing scratch start will be difficult and frustrating to learn on.

The Lift Start Method in TIG Welding

Lift start is a common method used on many TIG welding systems. To use this method, the welder will touch the electrode to the work piece, depress the foot pedal or finger switch, and “lift” the torch off of the workpiece to form an arc.

This arc initiation method is much smoother than scratch start and will not disrupt nearby sensitive electronics like high-frequency start circuitry can. Lift start is very often found on multi-process machines where the TIG process may only be used sparingly.

The High-Frequency Start Method in TIG Welding

This is the most common arc initiation method for industrial TIG welders. High-frequency start is the only true “touchless” method of arc initiation in TIG welding and is sometimes required in applications where any contamination of the weld puddle would result in a structural defect, most notably aluminum pipe work. High-frequency arc starting is also the most user-friendly method, as the welder may simply hold the torch where they want to start an arc and depress a foot pedal or finger switch. Machines which utilize scratch or lift start can be upgraded by adding on a module with high-frequency capability.

High-frequency systems can cause issues with nearby televisions, radios, computers, lighting, pacemakers and other sensitive electronics and machines equipped with high-frequency arc starting capability will usually have the option to switch to lift start when it is needed.

Scratch start, lift start, and high-frequency start all have their pros and cons, but it’s definitely important to know the difference to know when to choose each method for MIG welding.

For more information about TIG Welding practices, you can read more of our guides & blogs here at American Torch Tip.

Related Posts

Why TIG Welding Is Better Than MIG Welding

TIG welding and MIG welding both use electric arcs, filler metals and shielding gasses to create a weld. But their techniques, applications and finishes are quite different. As with any welding project, success depends on choosing the right processes and equipment, so we created a list of reasons to choose TIG welding over MIG welding. (Click here for the reasons to choose MIG welding over TIG welding.)

(more…)

Related Posts

Why MIG Welding is Better Than TIG Welding

Arc welding processes are as varied as the workpieces they create, and choosing the right one is vital to your project’s success. While MIG and TIG welding both form the weld using an electric arc, the techniques are quite different, and choosing the wrong one can lead to more than one headache. Read on for the reasons you may want to choose MIG welding vs. TIG welding. (Click here to learn why TIG is better than MIG.)

 

MIG and TIG welding both use an electric arc to create the weld. The difference between the two is the way the arc is used. MIG (metal inert gas) welding uses a feed wire that constantly moves through the gun to create the spark, then melts to form the weld. TIG (tungsten inert gas) welding uses long rods to fuse two metals directly together.

RELATED: Most Common Welding Equipment and Processes

Diversity

A number of reasons make MIG welding the superior choice for your job. First, it’s more diverse. While TIG welding can be used on more types of metals, it’s limited in its effectiveness on thicker jobs. MIG welding can be used on aluminum, stainless steel and steel, and on every thickness from 26-gauge sheet metal to heavy-duty structural plates.

MIG welding holds this big advantage over TIG because the wire feed acts not only as an electrode, but also as filler. As a result, thicker pieces can be fused together without having to heat them all the way through. And because it uses filler rather than fusing, MIG welding can be used to weld two different materials together.

Speed

Another reason for choosing MIG vs. TIG is speed. A MIG gun is designed to run continuously for long periods of time, making them more efficient and productive than its counterpart. For large, industrial operations that require high production rates, MIG is the go-to choice. (It also lends itself well to automation). Oppositely, TIG welding is much slower process that’s focused on detail.

Cost

As with any manufacturing job, time equals money. And because the MIG welding process is so much faster, it’s also more cost-effective. MIG parts are also more readily available and far less expensive than TIG.

Ease

Finally, MIG welding is easier to learn and can be perfected after just a few weeks of training. In fact, it’s even been referred to as the “hot glue gun” of welding — just pull the trigger to start or stop the weld. MIG welders can hold and operate the gun with only one hand, making it a better option for beginning welders. TIG welding, on the other hand, is a specialized technique that requires the use of both hands and one foot — all doing separate things.

RELATED: How to start a career in welding

For help with your MIG setup, download our free MIG Ultimate Troubleshooting Guide.

Related Posts

TIG Filler Metals and Their Best Uses

When choosing the right TIG filler metal, you will find a wide variety of products on the market. From steel, and aluminum, to an assortment of tungsten, there are many fillers to choose from. Each one has different benefits, so scope out the project at hand and make sure any filler you use is up to the task. You want to be sure to read any and all rod specifications before striking an arc.

(more…)

Related Posts