How to Set Up a TIG Welder for Mild Steel? Detailed Guide 2023

If you have started using a TIG welder, you know that this method requires some great skills. Although it is not among the easiest, once you master the art of setting up a TIG welder for mild steel, you will love it.

It would help if you spared extra time for learning as well as mastering the skill of TIG welding steel. As you will be working with Tungsten and Argon gas, you must be extra careful. You need more gas and must know the best TIG welding steel settings for best welding.

Back one year, when I needed clarification on some stuff, I found no specific article available online. There are various video lectures and written paragraphs on the topic, but there is no source to learn the topic completely. So, I decided that once I master how to set up a TIG welder for mild steel, I will write an article covering the whole subject from scratch.

Related: Wire feed weld process


TIG Welding and Mild Steel

If you are new to learning the TIG welding settings for mild steel, you must have noticed that TIG welding is a bit difficult. You will have to use both of your hands when doing TIG welding as one hand will hold the TIG torch while your second hand will continuously add the filler metal.

The process is also complex, as you have to make a proper arc while adding the right amount of filling metal. Although it is a difficult task, once you learn the skill, you will find the best method for welding steel as it is very versatile. With practice, you will develop the skill.

Using Tungsten to Weld Mild Steel

We usually talk about Tungsten whenever we talk about TIG welding mild steel settings, so let us explain Tungsten first. The core of TIG welding is Tungsten because, without it, there will be no TIG. Tungsten is a hard and brittle metal that is also radioactive. It has limited usage to other metals, but you can’t have it without Tungsten when it comes to TIG.

In TIG welding, the best Tungsten for TIG welding mild steel creates a non-consumable electrode and helps make the arc for the welding. Some common applications of Tungsten include rocket engines, old yellow bulbs, and heaters. Tungsten helps in maintaining the temp of arc at a constant 11,000 degrees F. Thus, a higher melting point, perfect electrical conductivity, and never burning up the electrode make tungsten an ideal choice.

How TIG Welding Works on Mild Steel?

So, let us move towards the most crucial part of this article: setting up a TIG welder. In TIG welding, we need three basic things to start with. These are heat, shielding, and filling metal.

The electricity that passes through the tungsten electrode creates heat, which forms an arc for welding. A compressed gas bottle will be helpful as you need shielding to protect it from the gas in the air. The filling metal will be a wire that you will dip into the arc and melt to fill the metal.

When people say that TIG weld steel is very hard to learn, it is because you have to bring all the above three things to the same place. You will use both your hands to make the finished product. First, you have to turn on the gas flow using the valve on your TIG torch, followed by holding the torch over the weld joint. Make sure not to touch the metal.

In the next step, you will need to press a good pedal and start the tungsten electrode’s arc using your TIG torch. Right after creating the arc, you will see that pieces of metal melt and form a liquid metal, a kind of a puddle. Then is the time to use your filling metal and fill the joint.


TIG Welder Power Supplies for Mild Steel

The power supply remains the same for mild steel, which we use for stick welding. However, you will need additional features for a proper TIG setup. The power supply of a TIG welding allows for constant amperage, which is crucial for your work as it regulates the amount of heat that is produced. The length of the arc will determine how much voltage you will need for TIG weld settings.

Feature 1: TIG High-Frequency Start

The most recent TIG power supplies come with the feature of a high-frequency start. This feature is crucial as it gives you a higher frequency to make an arc over a one-inch gap. Since the frequency will be higher, you don’t need to strike an arc physically.

Once you have formed the initial arc in a higher frequency, the voltage will begin dropping, and amps will take charge. Thus, it will save your Tungsten from contamination, and you can use it longer. The wear and tear on the Tungsten will also be less.

Feature 2: TIG Shielding Gas Pre-Flow and Post-Flow

Another cool feature in most TIG weld settings power supplies is the pre-flow and post-flow. You will use both of these options when needed so let us discuss how they are useful. A pre-flow feature will allow you to create a shield even before you plan to form an arc. Thus, the gas won’t react with the air.

On the other hand, the post-flow feature will keep a constant amount of gas going even after the arc stops. Thus, the weld will remain safe with the shielding until it cools. Welders usually use Argon and Helium for welding as they don’t react, but we will recommend Argon for mild steel.

Feature #3: AC Waveforms Controls

Another feature in TIG power supplies is that you can select your frequency settings as per the need. The settings you choose will have a direct impact on the welding arc, so they are crucial. You can use frequency range, electric pulses, or other adjustment settings. However, when working with mild steel, you won’t modify these settings as much as you need them while working with Aluminum or Magnesium.

TIG Welding Voltage Type and Welding Polarities

When it comes to voltage type, the same is similar to TIG welding as it was in stick welding. You can work on any of the two voltages, i.e., AC and DC. The DC welding TIG steel current will work the same way as it does in your car battery. The direction of the current will be single, and it will flow from negative to positive.

When it comes to AC, it works the same way as the current works in our home. The current can take multiple directions in a second as per the need. Depending on whether you need to weld deep or shallow, you can switch the polarities between DC electrode negative and positive, respectively.

In the DC electrode negative, you get 66% of heat in the welding metal, and it will weld deep. On the other hand, the DC electrode positive will place around 66% of the heat onto the electrode. Thus, you can better do shallow welding in TIG steel.

TIG Welding Machine Set-Up for Mild Steel

When it comes to setting up your TIG welding machine for steel TIG welding, there are two main options to play with. One of them is amperage while another one is gas flow. You will adjust the amperage based on how much thick metal you want to weld and how fast it melts the metal.

On the other hand, the cup size, welding conditions, and your way of welding will determine how much gas flow you need. For example, for a larger cup with windy conditions, you may prefer to work with more than 5 CFH.

TIG Welding Mild Steel

For setting up a TIG welder, your best options should be direct current electrode negative polarity along with Argon and Tungsten. Steel welding is the same as other metals, with a minor difference in that it requires more gas. So, a new person will take some time before he learns the skill.

Sanding Disk for Cleaning Mild Steel

Joint preparation is very crucial when you are welding steel with Tungsten. The joint should be completely clean before you start welding, or the filler material won’t flow well. You must clean the joint with a sanding disk to ensure the filler sticks well.

Final Thoughts

We covered the subject in detail, and now you clearly know how to set up a TIG welder for mild steel. We started with the importance of TIG welding, why Tungsten should be your choice, power supplies, polarities, and why you should keep the joint clean.

TIG welding is not among the easiest, and just reading won’t make you perfect. I still advise you to read the article again and keep practicing how to weld with a TIG welder. With practice, you will learn how to do perfect TIG welding.

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