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How To TIG Weld
Tungsten Inert Gas (TIG) welding is a precise and versatile welding process that offers unparalleled control and quality in metal joining. Welders consider TIG one of the most challenging methods to master, but the results in weld quality, cleanliness, and aesthetics are unmatched by other arc welding processes.
In this comprehensive guide, we'll delve into TIG welding, equipping both beginners and experienced welders with essential knowledge and techniques. From TIG welding basics and setting up your welding equipment to mastering the intricacies of electrode manipulation, we'll walk you through each step of how to TIG weld.
What Is TIG Welding And How Does It Work?
Gas Tungsten Arc Welding (GTAW), also known as TIG welding, is a metal joining process widely used to weld steel, stainless steel, and exotic metals such as aluminum, magnesium, nickel alloys, and more. When you start welding, an electric arc is formed between the non-consumable tungsten electrode and the workpiece. Tungsten has one of the highest melting points of 6,191.6°F, so the heat is directed into the weld joint, while the electrode is not consumed like a Stick electrode.
Depending on the thickness of the metal, TIG welding can be a fusion process. In micro TIG applications, or when welding thin metals with little to no gap, the heat of an arc is enough to fuse pieces together. However, when welding thicker pieces with a bigger gap, you will have to add filler material as TIG rods. Like Stick/Arc, TIG welding is a manual process, meaning you'll have to add the filler metal wire by hand.
Similar to MIG welding, the entire TIG welding process is protected by shielding gas. When heat is applied, both tungsten and weld pool are highly vulnerable to contaminants from the atmosphere. Oxygen, nitrogen, and other reactive gases can easily contaminate the molten metal, leading to various weld defects.
Source: https://www.technoxmachine.com/blog/mig-vs-tig-welding/
Gas Tungsten Arc Welding (GTAW) Equipment
Before you start to learn TIG welding, you first need to get familiar with common equipment used in TIG welding. To successfully weld and solve the puzzle behind the TIG welding, you will first need to understand how each piece of the equation works.
Common TIG welding equipment includes:
- Welding machine (TIG Welder)
- TIG Torch
- Filler metal
- Shielding gas
TIG Welder (Power Supply)
TIG welder is a primary piece of your TIG welding equipment, and these machines are known as power supplies. Their primary role is to utilize the input power of 110/220V (or even higher) from the power grid or generator and transform it into output power that we use to weld.
However, TIG welders are far from simple machines. TIG welders provide various settings to help welders perfectly control heat. Unlike most other machines, TIG Welders also successfully utilize AC current to weld aluminum and other exotic metals that require the cleaning action of alternating current.
This makes TIG welders more complex and pricier machines. As a beginner, it might take you time to understand and fine-tune all the settings. However, once you get the hang of your TIG welder, you get unlimited potential to weld various thicknesses and types of metal.
TIG Torch
In TIG welding, your torch is actually an electrode holder, but unlike Stick welding, the torches are a bit more complex. They have a unique appearance, and there are several pieces inside. When you first get your touch, you will have to assemble it, and common pieces are:
- Non-consumable electrode: Choosing the right tungsten will impact the final results of the weld.
- Collet: The collet holds the tungsten and is used to adjust the length that the tungsten protrudes from the cup,
- Collet body: a small copper body that has holes that distribute shielding gas to the weld.
- Cup: the final protection piece on the tip of the torch. The cup directs the shielding gas into the weld, and you can choose larger sizes or gas lens kits when more protection is needed.
- Back Cup: usually used to tighten the tungsten and make sure there are no contaminants coming from the back of the torch.
WP-17V-35 Air Cooled Valve Controlled Lift TIG WeldingTorch
TIG Filler Rod
The filler metal for TIG welding comes in the form of rods. TIG filler rods typically come in 3-foot lengths, packed in 10 or 50-pound boxes (or tubes). The diameter usually ranges from 1/16 to 1/4 inch. The American Welding Society ("AWS") has categorized the various alloys and assigned special AWS "ER" numbers to more easily identify them. The grades are similar to MIG welding wires.
Shielding Gas In TIG Welding
Shielding gas is a crucial component of TIG welding, and it can be highly responsible for weld quality. In this process, you'll have to protect both the tungsten and weld pool from contamination. Therefore TIG Welding requires inert gases such as argon or helium. Unlike MIG (Metal Inert Gas) Welding, you cannot add semi-reactive gases such as CO2 since they can contaminate the electrode.
Photo by @okieweld (TikTok)
How To TIG Weld - Detailed Guide For Beginners
Now that you understand how each piece of the TIG welding process works, it is time for the hard part - learning TIG welding. Since this is one of the hardest processes to master, it will take you time and patience to get everything right. However, we'll explain everything you need to know and equip you with theoretical knowledge you can later translate into your TIG welding skill.
To achieve sound and high-quality TIG welds, you'll need to go through several steps, from weld preparation setting up your TIG machine for first use and choosing the right tools and techniques to finish actions. So let's see how you TIG weld.
Safety First!
Welding is a hazardous profession, so the first step in a successful TIG weld should always be safety. Compared to other methods, TIG welding is often used in lower amp applications and thinner steel. That means that the overall heat is lower compared to Stick welding, so you can use lighter protective gear.
TIG welding requires dexterity, so you would want to use thinner fire-resistant Personal Protective Equipment (PPE). For example, TIG welding gloves are usually thin, and they will allow you to hold the torch and manipulate it perfectly while providing enough protection. When choosing an auto-darkening welding helmet for TIG, make sure it supports a low amp start so your eyes are protected even when welding down to 5-10 amps.
AP-1201-1 Heat-Resistant Fire-retardant Leather Welding Gloves
TIG Weld Preparation
TIG is an ultimately clean welding process, and dirt, rust, dust, or any contamination on the surface can interfere with the weld quality and damage the non-consumable tungsten. That's why you must clean all surfaces before welding. You can use mechanical removals such as a wire brush, grinder, or sanding paper to remove all contaminants from the surface, while chemicals and acids can deal with deeper layers.
Additionally, you will need to clamp down and align the pieces before welding. When welding thin pieces, you can opt to leave no gap and fusion weld them without a filler. With thicker pieces, you will need to leave a gap, and you can use a couple of tack welds to create an even weld joint. When TIG welding aluminum, you must remove the oxide layer with a stainless steel brush from the surface to get reliable and decent results.
Choosing The Right Tungsten Electrode
Tungsten electrodes come in a wide variety of sizes, lengths, and compositions. You can find TIG electrodes with diameters ranging from 0.040 "-3/16", composed of pure tungsten or with added oxides, 7" in length or shorter. Choosing the diameter of the tungsten will depend on the thickness of the metal you are welding. Still, for beginners, we recommend 3/32 or 1/16".
Tungsten electrodes are classified by AWS A5.12M/A5.12 classification, which specifies the color and allowed additives in each electrode. TIG welding used pure tungsten in the past, but due to poor welding characteristics, manufacturers started adding oxides.
When TIG welding steel, seasoned welders like to use 2% thoriated tungsten (red tip). Red tungsten works well with both thick and thin steel in AC/DC applications and provides a highly stable arc, good arc start characteristics, and final weld puddle results. However, present thoria can be radioactive when ground, so many welders today have started using lanthanated electrodes (Gold tip tungsten).
WL15 Series 1.5% Lanthanated TIG WeldingTungsten Electrode
Lanthanted tungsten is a good alternative and all-around choice for steel. It is durable and doesn't cause health issues, but it works worse on low-amp applications. So for the low amp-dc TIG steel welding, consider ceriated tungsten electrodes (gray), while blue tungsten works great on high-amp DC steel welding.
WC20 Series 2% Ceriated TIG WeldingTungsten Electrode
Somewhat the same rules apply to stainless steel. You can TIG weld stainless steel with thoriated, lanthanated, or ceriated electrodes. Meanwhile, to TIG weld aluminum, non-ferrous, and exotic metals, you will need an AC current and pure tungsten (green) or zirconiated tungsten (brown) electrode that works well with it.
Tungsten Preparation and Sharpening
After choosing the type of tungsten, you must select iif the tungsten tip is balled, pointed, or truncated. The electrode sharpening format directly influences the shape of the electric arc, and it can get from extreme 30 to 180 degrees. The sharper the TIG welding electrode is ground, the more targeted and narrow the penetration. At the same time, the load on the electrode tip is extremely high, which limits its service life. Meanwhile, as the angle increases, you get less focused penetration, and the welding arc starts to wander.
For beginners, we recommend using a YesWelder Diamond grinder and a grinding angle of 60°. This is an all-around choice that provides moderate penetration, moderate arc width, stable arc, and low risk of tungsten contamination. TIG welding aluminum will require a balled tip, which forms once you run AC through a pure tungsten electrode.
TTG02 Tungsten Electrode Sharpener Grinder
Choosing The Filler Rod For Steel, Aluminum, And Stainless Steel
As a beginner, you are more likely to use a TIG rod in your application, and choosing the right one isn't too hard. You'll have to consider the thickness of the rod and its composition. The length of the rods is usually 16". The composition of each TIG welding rod is classified by AWS. Simply put, the composition of your rod should be similar to the composition of the base metal:
- TIG Steel Welding Rods: ER70S-2, ER70S-6, and several other ER70S-series are your go-to choice for most steel welding applications such as construction work, farm equipment, shaft buildup, tanks, truck bodies, and general shop applications.
- TIG Welding Aluminum: ER4043 and ER5356 are the two most common aluminum welding rods that will cover most of your applications. ER4043 is typically used for most aluminum applications, while ER5356 is preferred when the finished piece is anodized.
ER4043 5LB Aluminum TIG Welding Rod
- TIG Welding Stainless Steel: There are a lot of stainless steel grades, but ER308L is considered an all-around choice for stainless steel 304, 304L, 308, 308L, 321, and 347. These are used in stainless steel fabrication of dairy, food, or restaurant equipment, chemical tanks, and general-purpose applications.
ER308L 5LB Stainless Steel TIG Welding Rod
AWS classification also includes rods for TIG Welding Titanium (ERTi) and other metals, but as a beginner, you are likely to use some of the rods listed above.
When it comes to the diameter of the TIG rod, the general rule is to use a filler rod with a size less than the thickness of the base metal. However, for thicknesses below 1/8", you can also use the same diameter rod in specific applications. For example, when welding 1/16" pieces, a 0.040" or 1/16 rod is recommended, while 3/16" metal will require 1/8" filler metal, and so on.
Source: https://www.weldingtipsandtricks.com/tungsten-electrodes-gtaw.html
Find A Suitable Torch And Assemble It
TIG torches come in various sizes, cooling options, and head designs, so you want to get the best out of it. You will need to assemble all parts before welding, but the provided torch might not always be the best. Since TIG welding requires dexterity, the bigger the better is not always the best approach.
Torches come in various sizes, but as a beginner, you are likely to deal with WP-17 and WP-20 torches. WP-17 are typically smaller torches rated at 150 amps, and they will cover most of your hobby welding. Since they are rated lower, they usually use an air-cooling system, which makes them lighter and more convenient. WP-20 are larger torches that can withstand 250 amp currents, and they can utilize a water cooling system to provide even a 100% duty cycle. However, water-cooled torches are bulkier, which makes them harder to use in light-duty applications and with delicate work.
SP-WP-18-5P TIG-250P ACDC Welder Specially Designed Water Cooled TIG Welding Torch
The torch head design can also help you with TIG welding. Most manufacturer-included torches provide fixed heads, and there is nothing wrong with that. However, advancements also brought flexible head torches. You can adjust the angle of the head to your applications for more convenient use, and there are also flex-lock torches.
Shielding Gas In TIG Welding
TIG welding shielding gas has to protect the tungsten electrode and molten weld puddle, so you will have to use inert gas, such as argon. Most of your TIG welding steel will require pure argon shielding gas (100% argon), but if you feel like you lack power, you can add helium. Similar to CO2 in MIG welding, helium will add penetration and stability to your arc. The mixture of 75% argon and 25% helium will show similar results to C25 in MIG welding (75/25 Argon/CO2).
When TIG welding stainless steel, you should add small amounts of hydrogen or nitrogen to argon. 2-5% hydrogen will stabilize the arc, increase heat, and weld fluidity when welding austenitic stainless steel and nickel alloys. 2% nitrogen can do the same in a duplex or super-duplex stainless steel.
The suitable gas flow will differ from the welding conditions, consumables, and shielding gas choice. Typically, suitable flow rates are between 10 and 35 cubic feet per hour (CFH). Our recommendation for indoor applications is 20 CFH, and you can increase it when there is a draft, outdoors, or when using helium. If you need better coverage in critical welds, you can use a gas lens that provides more consistent shielding gas coverage and reduces turbulence.
TIG Welding Polarity
TIG welding is always done in negative polarity, which means the torch goes into the negative (–) side, and the earth clamp goes into the positive (+) side of the welding cycle. Electrons run from the negative to the positive side of the circuit, so in the case of TIG, it is from your electrode holder into the base metal.
Source: https://www.weldclass.com.au/blog/39-the-tig-welding-process-your-questions-answered
If you reverse the polarity, the current will run from the workpiece into your electrode and torch tip, causing damage and burning both parts, while you'll get inconsistent weld results. When welding aluminum, exotic, or non-ferrous metals, you will want to switch from DC to AC current. AC brings enough cleaning action and good penetration by alternating from the positive to the negative side of the cycle.
Source: https://www.weldclass.com.au/blog/39-the-tig-welding-process-your-questions-answered
TIG Machine Settings
TIG machines use a constant current power source, which means that you set the desired amperage, and the machines make it consistent throughout the process. You adjust the voltage by manipulating the arc length with your torch. In that manner, only changing the amperage is relatively easy and usually done according to material thickness.
However, TIG welders today are pretty advanced machines that will allow you to fine-tune and perfectly control each step of your welding. So, as a beginner, the first impression of setting up your welder can feel like flying a spaceship with all the flashing lights. However, things are not as complicated once you get a hang of it.
TIG welders such as YesWelder TIG 200P AC/DC will allow you to control several steps of welding, including:
TIG-200P-AC/DC AC Aluminum TIG Welder
- Starting amps: these are important for delicate metals that can warp due to high initial heat
- Upslope: as the process goes on, the welder gradually increases the amperage (upslope) toward the peak amps
- Peak amps: the primary amperage you set on your machine
- Downslope: during the finishing, the welder gradually reduces the amperage (downslope) to end amps
- End amps: finishing amperage used to avoid burning through the end of the piece and allowing the metal to fill the end of the joint
- Post-flow: shielding gas can flow for a couple of seconds after the end of the weld to promote cooling and extend the life of consumable parts of the torch.
AC/DC TIG welders will also provide features such as pulse or AC balance. Pulsed TIG welding includes arc oscillating through low and high amperage to avoid overheating and burning through delicate and thin metals such as aluminum or thin steel. By adjusting a pulse rate (Hz), you can adjust how many cycles there will be. Pulse Width will determine how long the peak current lasts in each pulse cycle. As a result, you can input less or more heat by modifying the peak current duration vs. the background current duration. AC balance will allow you to set how much of the time current spends in high and low parts of the cycle or the balance between penetration and cleaning.
TIG Welder Start
TIG welding machines can have a different way of starting an arc. So when browsing a market, you can encounter high-frequency, scratch, or lift TIG machines.
- High frequency: This is the easiest and cleanest start, and it is recommended for most applications and beginners. The machine senses the presence of a circuit and initiates an electric arc without touching the base metal. This makes it highly easy to use, and there are no contaminations.
- Lift start: lift start is also an easy-to-start method, but it involves touching base metal with tungsten. To start an arc, you have to touch the base metal with tungsten, and as you lift it, the arc is formed.
Source: https://weldguru.com/scratch-start-tig-vs-lift-arc/
- Scratch start: this is the oldest method you want to avoid due to the higher skill requirements and more contamination. To start an arc, you'll have to scratch the base metal with tungsten, similar to lighting a match, which can be harder to perform.
Source: https://weldguru.com/scratch-start-tig-vs-lift-arc/
Torch Control Or Foot Pedal
TIG Welding allows you to control your welding perfectly, and if you want further control, you can use a foot pedal. The foot pedal will allow you to adjust the amperage "on the go" as you are welding. Since both your hands are busy, controlling an amperage by your foot is highly convenient.
However, as a beginner, you are less likely to use it immediately. Some troches will even have an incorporated gas valve or control button so that you can do some control directly on your torch.
TIG Welding Technique And Tips
Once you prepared and adjusted everything, it is time to lay your first bead. Instead of welding directly on your peace, use scrap metal of the same thickness to practice.
Here are some TIG welding tips:
- Wielding torch: Take your torch in the dominant hand, rod with your other hand, and dip it into the molten pool.
- Always push: A push angle means your torch is over the weld, and you push the weld pool along the joint.
- Keep your torch at a 75° angle as you push. If you're welding in a fillet joint (a corner join), your torch will be angled into it at a 45° angle.
- Keep the distance between your tungsten and workpiece consistent, approximately 1/8-1/4 inch. Don't touch the base metal with the tip of the electrode.
- Feed angle: Your filler wire should come in from relatively low, almost parallel with the joint, with a slight 10° to 15° angle.
- Try to catch the rhythm of the move and dab action. Going too slow will cause excessive penetration, and going too fast will cause incomplete penetration.
- Keep things clean: TIG welding is a clean process that will yield the highest-quality and purest welds if you spend enough time preparing pieces.
Practice Is Crucial
In the end, it all comes down to practice. Welding is one of many skills that will take you years to fully develop and perfect, and TIG welding, specifically, can take even more. So don't get disappointed if you fail at first. Weld preparation, equipment, and parameter selection are almost half of a successful TIG weld. So, always try to fine-tune and troubleshoot your welds by looking at your TIG weld puddle.
TIG welding technique is also considered more challenging since you are using both hands to manipulate the torch and dip the filler rod. Finding the perfect balance between travel angle, work angle, and travel speed and combining it with filler distribution is crucial in creating sound and everlasting TIG welds.
🧐How To TIG Weld - FAQ
1. What Is TIG Welding?
Gas Tungsten Arc Welding (GTAW), also known as TIG welding, is a metal joining process widely used to weld steel, stainless steel, and exotic metals such as aluminum, magnesium, nickel alloys, and more. When you start welding, an electric arc is formed between the non-consumable tungsten electrode and the workpiece. Tungsten has one of the highest melting points of 6,191.6°F, so the heat is directed into the weld joint, while the electrode is not consumed like a Stick electrode.
2. What are TIG welding tips?
- Wielding torch: Take your torch in the dominant hand, rod with your other hand, and dip it into the molten pool.
- Always push: A push angle means your torch is over the weld, and you push the weld pool along the joint.
- Keep your torch at a 75° angle as you push. If you're welding in a fillet joint (a corner join), your torch will be angled into it at a 45° angle.
- Keep the distance between your tungsten and workpiece consistent, approximately 1/8-1/4 inch. Don't touch the base metal with the tip of the electrode.
- Feed angle: Your filler wire should come in from relatively low, almost parallel with the joint, with a slight 10° to 15° angle.
- Try to catch the rhythm of the move and dab action. Going too slow will cause excessive penetration, and going too fast will cause incomplete penetration.
- Keep things clean: TIG welding is a clean process that will yield the highest-quality and purest welds if you spend enough time preparing pieces.
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