TIG Welding For Beginners

Starting your TIG welding journey may seem daunting, but fear not! This comprehensive guide will walk you through the initial setup of your TIG welder, ensuring that you’re well-prepared for your first welding project. From assembling your TIG torch to selecting the right shielding gas and filler metal, we’ve got you covered. Let’s dive into the world of TIG welding.

TIG Welding Safety:

It is vital to prioritise safety when TIG welding. Proper eye protection from UV/IR radiation and safety gloves is a must. While gloves are necessary, you should opt for lightweight goatskin gloves for improved dexterity. Explore TIG welding helmets, like the Stealth Proline Welding Helmet, which auto-darkens based on your TIG torch activity, ensuring comprehensive protection.

Understanding the TIG Welding Process:

Here you will gain insights into the theory behind TIG welding, an arc welding process utilising electricity to melt base and filler metals. The TIG is an arc welding process. Basically, it uses the resistance to the flow of electricity to heat and melt the base and filler metal. The power source (your TIG welder) sends electricity through the TIG torch, which goes through the welded material and flows through the ground clamp back into the welding machine. Then, this closed circuit causes the welded metal to melt because it heats due to electrical flow resistance. 

But you’ll get different results depending on if you hooked the TIG torch to the positive or negative plug on your welder. Polarity plays a crucial role, influencing weld results. We’ll discuss the polarity setup later in the article, and you’ll see how to use polarity to your advantage and achieve better welds on various metals.

Setting Up Your TIG Welder:

A TIG torch is composed of a torch body, short or long back cap, collet, collet body, ceramic cup, and a tungsten electrode. You can replace the collet body with the gas lens kit for improved shielding gas flow, but it’s not necessary for most jobs.

Follow these steps for easy TIG torch assembly:

1. Screw the collet body into the front of the torch’s head snugly. 
2. Insert the collet into the collet body from the rear part of the torch head.
3. Screw the back cap to the rear of the torch but only slightly. Don’t tighten it just yet.
4. Insert the tungsten electrode from the front through the collet body and the collet.
5. Screw the ceramic cup (pink nozzle) over the collet body from the front of the torch.
6. Adjust the tungsten stickout by untightening the back cap, which allows you to move the tungsten freely. Once      you are satisfied with the stickout, tighten the back cap, and the tungsten electrode won’t be able to move              anymore. Don’t overtighten the cap because you can deform the collet and lose the grip over the electrode            inside it. 

Shielding Gas Selection

Choosing the shielding gas is the easiest part of a TIG welding setup. You will almost always need a 100% argon gas bottle. 

Pure argon works for TIG welding all metals from steel to aluminium and copper. But you can include some helium in the mix to improve weld penetration if your TIG welder’s amperage output is below the required for the welded thickness. For example, if your TIG welder can output 200A, but you wish to weld 1/2-inch thick aluminium, adding helium would improve puddle wetting and penetration.

Also, you will need a shielding gas regulator, like the Single Stealth Tig Flow Meter. Its purpose is to regulate the gas pressure (gas flow rate) released from the gas bottle. Still, it is important to remember that some metals and joint types require higher and some lower flow rates.

How to set up your gas regulator.

Screw the gas regulator’s inlet valve into the gas tank while the main gas tank’s valve is shut. First thing to remember is to stay clear from the regulator’s path before releasing the gas from the bottle’s main valve. If your regulator gets damaged, its pressure gauge can explode, so it’s safer to always position yourself away from its trajectory path until you verify everything is working correctly.

Once the regulator is installed, attach the gas hose to its outlet valve and connect it to your TIG welder’s inlet valve. Additionally, if your TIG welder doesn’t have an inlet valve, you can attach the gas line directly to most TIG welding torches.

Most TIG welding jobs require about 15-20 cfh shielding gas flow. However, some complex joints may require a higher flow. Likewise, making out-of-position welds needs higher shielding gas flow to compensate for gravity pulling down the gas. For a more in-depth guide in shielding gas flow for your torches, check out our All About Tig Cups post.

Filler Wire Selection

Filler Wire Selection:

It’s vital to select the appropriate filler metal wire based on the material you’re welding. For example, here are some common choices for mild steel, stainless steel, and aluminium, to ensure that you’re well-equipped for your specific welding needs.

Polarity – DCEN, DCEP, And AC Explained:

You must choose a suitable polarity when using the TIG machine in the DC output mode. Your electrode (TIG torch and its tungsten) can either be positive or negative, and for that reason you set the polarity by plugging the TIG torch into the positive or negative DINSE socket on the front of your TIG welder.

So if you wanted to use DCEN (direct current electrode negative), you would plug the TIG torch into the negative DINSE socket and the ground clamp into the positive DINSE socket. 

While most DC TIG welding applications require the DCEN polarity setup because the DCEN provides the deepest penetration and concentrated heat input. Therefore, you need to use the DCEN setup for steel, stainless steel, nickel alloys, copper, and similar materials.

However, when it comes to TIG welding aluminium and magnesium,  you must use AC TIG. This is because the AC alternates the polarity between DCEN and DCEP many times per second. You can’t weld aluminium without the DCEP because the DCEP is crucial for aluminium oxide removal from the surface. So, DCEN provides weld penetration, but DCEP removes oxides and ensures a clean, strong aluminium weld.

TIG Welder Settings:

TIG welders can have as little as one setting to adjust amperage output or tens of settings for professional TIG welding applications. Many TIG machines are loaded with settings to help you adapt your welding arc precisely as you want it. 

Let’s start with the basic settings and work our way to the high-end settings you can find on TIG welders.

• Amperage Output – Most small TIG welders only support amperage output settings.
• AC Frequency – AC frequency determines how many times DCEP and DCEN alternate using AC TIG. This determines how focused vs. how wide the arc is.
• AC Balance – AC balance determines the length of DCEN and DCEP portions of one AC cycle. It allows you to modify how much penetration vs. cleaning action you want the welder to perform.
• AC or DC Pulse – Pulse settings alternate between the high (peak) and low (background) current, reducing the average input into the joint. Both DC and AC pulsed TIG is used to prevent burn-through and warping on thin materials, and corrosion resistance loss on stainless steel. 

• Peak Current – Peak amperage output of a single pulse.
• Background Current – Lowest amperage output of a single pulse
• Pulse Frequency – Determines how many times per second the peak and background currents switch. For example, 100 pulses per second means that the peak and background current switch 100 times per second. 
• Pre-flow – The length of time how long the shielding gas flows from the TIG torch before the arc is initiated. This is used to soak the joint into the protective gas before welding sensitive metals.
• Post-flow – Determines how long the shielding gas will flow from the torch after you turn off the arc. This is a highly useful setting when welding sensitive metals like stainless steel and titanium, which tend to oxidate as the weld cools.

With this in mind, some settings are only available using the 4T mode instead of a TIG foot pedal. You can either use a foot pedal to vary output current by “throttling” up or down on the pedal, use 2T mode as the most basic on/off current, or use 4T mode which allows you a bit more control than 2T but less than the pedal.

Settings available with 4T on some TIG welders are:

• Initial Current– The starting arc current. This current is released immediately after the pre-flow ends and after you touch the torch’s button. Generally, a lower current is desired when welding thin stock to prevent burn-through during arc ignition.
• Upslope Time – The time it takes for the initial current to rise to the peak set current.
• Peak Current – The highest current value you set to weld 99% of the joint’s length.
• Downslope Time – Determines how long it takes for the peak current to drop to the ending current as you touch the power button on the torch to turn off the arc.
• Ending Current – Ending current allows you to fill in the crater at the end of the weld and slowly cut out the arc to prevent thermal shocks of the material. 

You can have three arc-starting methods for TIG welding, and they have varying degrees of quality.

• Scratch start – The most basic TIG arc starting method. Scratching the welded metal with the tungsten tip initiates the arc, but it increases the chances of polluting the weld with the tungsten inclusions.

• Lift arc start – More advanced arc starting method. Just by gently touching the welded metal’s surface and lifting the torch, the arc is initiated. Still, there are chances of minor tungsten inclusions, which could weaken the weld.
• High-frequency start (HF start) – The best way of initiating the TIG arc. There is no physical contact between the tungsten and the welded metal. The arc jumps from the tungsten tip to the metal once you press the pedal or the torch’s button.

TIG Welding Basics:

With your TIG welder set up, it’s time to dive into the basics of TIG welding. When it comes to beginners it’s best to practice on mild steel with a clean DC TIG setup before exploring pulse settings and AC TIG for aluminium. In order to achieve flawless welds it is vital to master proper torch and filler metal handling techniques. 

Firstly, make sure you keep a firm grip over the TIG torch and position it at an angle of 70 or 80 degrees to the welded piece. Secondly, keep the tungsten within 1/16 to 1/8 inch above the workpiece. However, be careful not to allow the tungsten to make contact with the welded material, as this will contaminate the weld metal and require regrinding the tungsten.

Since it requies both hands, precision is needed when TIG welding. The torch must be held with one hand and the filler metal rod with the other at about 15 degrees to the welded piece. It’s vital to keep the tip of the filler metal rod inside the shielded gas atmosphere, or it will oxidate at such high heat near the arc. 

Final Thoughts:

Setting up your TIG welder is a manageable process, but mastering advanced features requires practice. Experiment with settings on scrap metal to find your preferred arc characteristics. Remember, there’s more than one path to a successful TIG weld, so embrace the trial-and-error process to refine your skills. Happy welding!

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