TIG Welding Guide: Master GTAW Setup, Technique & Troubleshooting

A friend of mine spent an entire Saturday trying to weld a set of thin stainless tubing for a motorcycle exhaust, and by evening he had a pile of scorched metal and a nasty case of arc-eye. The problem was not his hands; it was that nobody had ever explained the science behind TIG welding to him. This guide walks through exactly what TIG welding is, how to set it up correctly, and how to fix the mistakes that almost every beginner makes.

Introduction: Why TIG Welding Rewards Patience and Understanding

A friend of mine once lost an entire Saturday to a motorcycle exhaust. He was welding thin stainless tubing for a custom build, and by evening he had a pile of scorched, warped metal, a tungsten he kept re-grinding, and a painful case of arc-eye. His hands were steady enough. The real problem was that nobody had ever walked him through the science behind the process. He was trying to learn TIG by feel alone, and TIG does not surrender its secrets that way.

That story is more common than you might expect, and it is exactly why this guide exists. If you have been asking what TIG welding actually is, what equipment you genuinely need, and why your beads keep coming out worse than the ones in the videos, you are in the right place.

TIG rewards patience because it makes you the entire feedback loop. The puddle tells you everything: its color, its width, the freeze lines trailing behind it. The welders who struggle are usually the ones moving too fast, watching the arc instead of the pool.

What Is TIG Welding, Exactly?

TIG stands for Tungsten Inert Gas welding. Its formal engineering name is Gas Tungsten Arc Welding, or GTAW, the term you will find on weld procedure specifications, shop drawings, and American Welding Society standards. Both names describe the same process, and you should be comfortable reading either one.

In TIG welding, an electric arc is struck between a non-consumable tungsten electrode and the metal being joined. “Non-consumable” is the key idea: the tungsten generates the heat but never melts into the puddle. Instead, the welder feeds a separate filler rod into the molten pool by hand, or joins the metal with no filler at all, a technique called autogenous welding. Meanwhile, a stream of inert shielding gas, usually pure argon, blankets the puddle and keeps oxygen, nitrogen, and moisture out of the molten metal before it solidifies.

That division of labor is what makes TIG special. Heat input, filler addition, and travel speed become three separate variables you control independently. It is also why TIG carries the steepest learning curve of the common arc processes: no flux coating hides imperfections and no wire feeder does half the work for you. In return you get the cleanest, most precise, most controllable weld of any widely used arc process, which is why TIG is the process of choice for precision fabrication work. It is the default wherever failure is not an option: aerospace structures, food-grade and pharmaceutical stainless tubing, pressure vessels, and high-end motorsport fabrication. If that world interests you, our guide to aerospace TIG welding covers the standards and training paths behind it.

How TIG Differs from MIG and Stick Welding

If you have already tried MIG or stick, the differences are obvious within a minute at the bench. With MIG, a continuously fed wire electrode melts into the puddle, so the wire is simultaneously the heat source and the filler metal. That makes the process fast and forgiving, as our aluminum MIG welding guide explains in detail. Stick welding uses a flux-coated consumable electrode that burns off and leaves a protective slag layer you chip away after the pass.

TIG uses neither. The electrode does not melt, no flux is involved, and there is no slag to clean up. That is why TIG welds come out so clean, and also why the process is slower and demands more operator skill. It is worth being honest about the trade-off: knowing when stick welding still wins makes you a better welder than insisting on TIG for everything. Most beginners describe the same progression: frustration first, then a genuine breakthrough somewhere around the fiftieth bead.

What This TIG Welding Guide Covers

This is an informational guide, not a product catalog. Over the next nine sections, we work through the process in the order you actually need it:

• The fundamentals of GTAW: electrode, gas, polarity, and arc starting
• Equipment: machines, torches, foot pedals, and gas gear
• Tungsten electrode selection, color coding, and tip preparation
• Shielding gas, flow rates, and filler metal choice
• Machine setup: amperage, AC balance, AC frequency, and pulse
• Technique: torch angle, arc length, reading the puddle, and feeding filler
• Welding carbon steel, stainless, aluminum, and exotic metals
• A symptom-by-symptom troubleshooting and repair table
• Safety, a structured practice plan, and when formal training pays off

By the end, you should be able to walk up to an unfamiliar TIG machine, set it correctly for the material in front of you, and explain why every dial sits where it does. That is the real divide in welding: setting a machine by rote versus understanding it. Safety runs through everything that follows, from arc radiation and fume exposure covered under OSHA’s welding, cutting, and brazing rules to respirator requirements for confined spaces, so do not skip the final section even when you are eager to strike an arc. The next section starts at the beginning: what is actually happening inside that quiet, hissing arc.

What Is TIG Welding? The Fundamentals of GTAW Explained

TIG stands for Tungsten Inert Gas, and its formal name from the American Welding Society is Gas Tungsten Arc Welding (GTAW). Unlike stick or MIG, the tungsten electrode never melts to become part of the weld. Instead, it solely creates the arc while filler metal, when needed, is fed separately by hand. An inert shielding gas then protects the entire weld zone from the surrounding air, allowing for some of the cleanest and most precise welds possible.

The Four Core Elements of GTAW

For a GTAW setup to work, four components must work in sync:

• Tungsten electrode: A non-consumable rod, often alloyed with oxides like thorium, cerium, or lanthanum. It’s ground to a point for most DC work or balled for AC work to help direct the arc.
• Shielding gas: Nearly all TIG welding is done with 100% argon. Helium or argon-helium blends can be used in more specialized industrial applications to influence heat transfer.
• Constant-current power supply: The defining electrical trait of TIG. Rather than adjusting to hold a voltage like a MIG machine, a constant-current (CC) machine holds the amperage you set, even if your arc length fluctuates. This allows for incredibly tight heat control, a point further detailed by Miller Welds.
• Filler rod: A separate consumable fed by your off-hand into the leading edge of the puddle. Since it never makes direct contact with the arc, heat and filler can be controlled independently.

This separation of heat and filler is why GTAW is the go-to process for critical work in aerospace, food-grade stainless tubing, and exotic alloys, all of which often fall under procedures outlined by AWS standards.

Creating and Controlling the Puddle

When the arc strikes, electricity jumps from the tungsten tip through ionized shielding gas to the workpiece, forming a plasma arc. This concentrated arc produces heat anywhere from roughly 6,000 to 20,000°F, melting only a small area of the base metal to form a puddle. With a constant-current machine, changing your arc length (ideally about the diameter of your tungsten) will primarily affect voltage and heat spread, not your set amperage. Keeping that arc short is key to keeping the heat focused.

Polarity: Matching Current to the Metal

Choosing the correct polarity is one of the most important fundamentals for GTAW.

• Direct Current Electrode Negative (DCEN): With this setup, roughly two-thirds of the arc heat goes into the workpiece. It produces deep, narrow penetration and keeps the tungsten cool. DCEN is used for carbon steel, stainless steel, copper, and titanium.
• Alternating Current (AC): AC rapidly flips between electrode-negative and electrode-positive. The electrode-negative half-cycle provides penetration, while the electrode-positive half-cycle provides a cleaning action by breaking up the tough aluminum oxide layer. Since aluminum oxide melts at about 3,700°F and aluminum underneath melts at roughly 1,220°F, this cleaning action is required to achieve a sound weld on aluminum.

Arc Starting Methods

How an arc is initiated can directly impact tungsten life and puddle cleanliness:

• Scratch start: Dragging the tungsten across the metal like striking a match. While inexpensive, it can deposit tungsten into the puddle and is mostly found on basic combo machines.
• Lift start: The tungsten touches the workpiece and is lifted to initiate the arc as current ramps up. This is cleaner than scratch start and is common on many portable inverters.
• High-frequency (HF) start: A high-voltage, high-frequency burst ionizes the gas gap, allowing the arc to jump without any contact between tungsten and the metal. This prevents tungsten contamination, preserves tip geometry, and is especially important for AC welding on aluminum.

Essential GTAW Terminology

Term	Meaning
Puddle	The molten pool of base metal that you watch and control with heat input.
Arc length	The distance between the tungsten tip and the puddle. A shorter arc length keeps the heat focused and more controllable.
Travel angle	The torch tilt from vertical, typically 10–15 degrees, used when pushing or pulling the arc.
Bead	The solidified weld deposit. Its shape is one of the clearest indicators of proper settings and consistent travel speed.
Heat-affected zone (HAZ)	The area of base metal adjacent to the weld that changed microstructurally from heat without melting. Managing its size is especially critical on stainless steel and aluminum.

With these fundamentals in place, the puddle becomes readable feedback for every adjustment made at the torch. From here, the focus shifts to the equipment needed to put this precise control into practice.

TIG Welding Equipment: Machines, Torches, and Essential Gear

A TIG setup is a small system: power source, torch, gas delivery, controls, and consumables that all have to work together. Buy mismatched pieces and you will spend more time fighting the gear than learning the craft. Here is what each component does and how to choose wisely.

TIG Machine Types: Transformer, Inverter, and Multi-Process

Older transformer machines are heavy, simple, and nearly indestructible. They run on conventional technology, so they are bulky and offer limited arc control, but a well-built transformer unit can outlive its owner.

Inverter machines are the modern default. They convert incoming power electronically, which makes them dramatically lighter and gives the electronics far more influence over the arc: fine low-amp starts, pulse settings, and precise digital displays. Miller’s TIG welding knowledge hub has a useful overview of how these machines shape the arc (Miller Welds TIG resources).

Multi-process machines combine TIG, stick, and often flux-cored welding in one box. They are attractive for hobbyists who want one machine for everything, but check the fine print: some budget units only offer DC TIG, which rules out aluminum, and some omit the foot pedal or high-frequency start that proper TIG work depends on.

Machine type	Weight	Arc control	Best suited to
Transformer	Heavy	Basic	Fixed shop stations, rough service
Inverter	Light	Fine, often pulse-capable	Most TIG work, portability
Multi-process	Light to medium	Varies by model	Hobbyists wanting one machine

Two numbers matter most when comparing machines. First, AC/DC capability: DC is enough for steel, stainless, and titanium, but aluminum requires alternating current, so an AC/DC machine is the flexible choice. Second, amperage range: a 200-amp AC/DC unit handles the vast majority of sheet and plate work, while thin material demands a machine that starts and holds a stable arc as low as 5 to 10 amps.

The Torch and Its Consumables

Torches come in two cooling flavors. Air-cooled torches rely on ambient air and the shielding gas to shed heat. They are simple, light, and maintenance-free, but the cables are thick and heavy, and their output is limited, typically up to the mid-hundreds of amps with reasonable comfort.

Water-cooled torches circulate coolant through the handle. They manage higher amperage and longer duty cycles but add complexity: extra hoses, a cooler or water line, and connections that can eventually leak. For occasional bench work on thin material, air-cooled is honestly easier to live with; for production or high-amperage aluminum, water cooling pays for itself.

The torch head itself is a stack of small parts:

• Back cap — seals the torch body and sets how far the tungsten protrudes.
• Collet body — routes gas and houses the collet.
• Collet — the split chuck that clamps the tungsten when you tighten the back cap.
• Cup (nozzle) — shapes the gas envelope around the arc.
• Gas lens — a mesh insert that replaces the standard gas distributor.

A gas lens improves shielding gas coverage by creating smoother laminar flow around the tungsten. The practical payoff is a wider, calmer gas envelope, so you can often lower your flow rate, extend the tungsten further out, and still get cleaner welds. It is one of the cheapest upgrades in TIG welding. If you are sourcing torch parts and cylinders, a walk-through like the Airgas Welding Equipment Guide helps you match consumables to your torch model.

Controls, Cables, and Gas Delivery

The foot pedal is the heart of TIG heat control. It lets you start soft, ramp up as the puddle forms, and back off at the end of a bead, all without stopping. Machines without a pedal often use a fingertip amperage control on the torch, which is handy for overhead and out-of-position work where a pedal cannot reach, though it lacks the same smooth modulation. Some offer both.

Don’t overlook the humble hardware: quality interconnect cables with tight DINSE-style connectors, a ground clamp kept clean and biting onto bare metal, and a properly rated gas regulator and flowmeter so you can read your flow in cubic feet per hour instead of guessing from a dial. Cylinders, regulators, and argon supply details are covered in the Airgas Welding Supplies buyer’s guide.

A Practical Buying Framework: Hobbyist vs. Professional

Priority	Hobbyist / occasional welder	Professional / production
Machine	Inverter AC/DC, 160–200 A	Higher output, high duty cycle, pulse
Torch	Air-cooled, lighter	Water-cooled, flexible heads
Controls	Foot pedal first	Pedal plus fingertip or 2T/4T
Extras	Gas lens upgrade later	Spares, service network, multi-process

Buy the widest amperage range and best arc control you can afford, choose the torch based on how long and how hot you actually weld, and resist paying for features you will never switch on. If you are considering TIG as a career path rather than a hobby, structured Aluminium Welding Course: What You Learn, Costs & Careers programs usually include machine setup and equipment theory as core modules, which saves a lot of trial-and-error spending.

Tungsten Electrodes: Choosing Colors, Sizes, and Preparing the Tip

If one component confuses new TIG welders more than any other, it is the tungsten electrode. It sits inside the torch, carries the current, and forms the arc, yet it is non-consumable—it should never melt into the puddle the way a stick electrode does. Everything about your arc quality, from how focused it is to how much current it survives, starts with the little rod you load into the collet. Choose the wrong one, or grind it wrong, and no amount of hand skill will save the weld.

What a Tungsten Electrode Actually Does

Tungsten has the highest melting point of any pure metal, roughly 3,422°C, which is why it can sit at the tip of a 150-amp arc without turning to liquid. The electrode does three jobs: it conducts current to the arc, it concentrates that current into a sharp point so the arc stays stable, and it emits electrons efficiently so the arc lights and stays lit. Pure tungsten handles the melting-point part but emits electrons poorly, which is why manufacturers alloy it with small percentages of oxides—thorium, cerium, lanthanum, zirconium—to lower the work function and make arc starting easier. That alloying is what the colored bands on the end of each tungsten mean, and it is the most useful piece of information on the package.

Color Codes: Matching Tungsten to the Job

Tungsten color coding follows the AWS/ISO standard, though a few legacy designations still circulate in older shops. The practical rundown:

Color Band	Type	Typical Current	Best Fit
Green	Pure tungsten (99.5%)	AC	Traditional choice for AC aluminum work; forgiving on a ball tip, but the lowest current capacity of the group
Red	2% thoriated	DC	Excellent electron emission and arc starting; the long-time standard for steel and stainless on DCEN
Gray	Ceriated (2%)	DC, some AC	Starts easily at low amperage; good for thin material, tube work, and repair
Gold	1.5% lanthanated	AC and DC	Versatile all-rounder with high current capacity; handles aluminum and steel without a swap
Blue	2% lanthanated	AC and DC	Similar to gold, slightly harder-wearing; a favorite for heavy AC aluminum work
White / Violet / Orange	Rare-earth blends (ceriated-lanthanated mixtures)	AC and DC	Modern multi-purpose electrodes positioned as safer alternatives to thoriated types

For a beginner who wants one tungsten that does almost everything, lanthanated (gold or blue band) is the usual recommendation. Pure green tungsten is still commonly taught for AC on aluminum because it forms a clean ball tip, but it has noticeably lower current capacity and struggles on thicker sections. For aluminum-specific prep, our guide to aluminum cleaner for welding covers the oxide removal that goes hand in hand with tungsten choice on aluminum joints.

Health and Handling: The Thoriated Question

Thoriated tungsten (red band) contains about 2% thorium dioxide, a low-level radioactive material. In normal welding it poses no radiation hazard to the welder, but grinding it produces a fine dust that should not be inhaled. The CDC’s NIOSH welding resources and its toxicology profile for thorium both flag dust exposure as the route of concern, and OSHA’s general welding, cutting, and brazing standards require employers to control airborne contaminants from these processes. In practice: grind thoriated tungsten inside a local exhaust hood, wear a properly fitted respirator rated under OSHA’s respiratory protection standard 1910.134, and wet-wipe or HEPA-vacuum your grinder bench rather than blowing it off with compressed air. If that sounds like more shop infrastructure than you want, ceriated or lanthanated tungsten gives nearly the same arc performance with none of the radiological paperwork, which is why American Welding Society guidance increasingly points hobbyists and small shops toward rare-earth alternatives. Our Airgas welding supplies guide walks through how packages are marked so you can compare tungsten labeling side by side at most suppliers.

Sizing, Tip Geometry, and Grinding Direction

Tungsten diameter should roughly track your amperage range: 1/16-inch handles about 20–60 amps, 3/32-inch covers roughly 60–150 amps, and 1/8-inch is for heavier current above that. Oversized tungsten at low amperage gives an arc that will not focus; undersized tungsten at high amperage overheats, tapers, and drops an oxide ball into your puddle.

Preparation is where most arc problems are actually born. The rule that matters most: grind longitudinally, running the grinding wheel parallel to the electrode axis, never around the circumference. Longitudinal grind marks act like microscopic flutes that channel electrons forward, producing a stable, focused arc that stays pointed where you aim it. Circumferential grinding scatters the arc sideways and causes the wander beginners mistake for shaky hands. Miller’s TIG welding knowledge base also recommends dressing the tungsten on a dedicated, contamination-free diamond wheel kept for tungsten only.

Taper geometry changes with the current. For DC on steel and stainless, grind a long, narrow taper—roughly a 2-to-1 length-to-diameter ratio with an included point angle near 30 degrees—for deep, focused penetration. For AC on aluminum, traditional practice balls the tip: ramp the current up and let the end form a shallow dome slightly wider than the rod, which resists the spitting you get from a sharp point on AC. Modern inverter machines with balanced AC waveforms are increasingly run with a truncated or lightly ground flat tip on aluminum instead of a ball, giving better arc starts and longer electrode life.

When Contamination Strikes

If the tungsten touches the puddle, the arc goes wide and mushy and the electrode picks up molten base metal. You cannot fix a contaminated tip by grinding around the affected area—you cut or snap off the contaminated end with side cutters, regrind longitudinally to your target geometry, and reload. Welding schools drill this fix until it becomes reflex, which is one reason formal aluminium welding courses spend real hours on tungsten discipline before students ever strike an arc. The same discipline applies at the professional level; aerospace work, covered in our aerospace TIG welding overview, treats electrode preparation as a documented process step because arc consistency is directly tied to weld quality in thin-wall tubing.

The takeaway is simple: the tungsten is cheap, the arc it produces is everything. Match the alloy to your current, grind it lengthwise, keep it clean, and replace it the moment it looks doubtful. A well-prepared electrode does most of the work of a stable arc before you ever strike it.

Shielding Gas, Flow Rates, and Filler Metal Selection

Two consumables decide whether a TIG weld comes out clean or full of holes: the gas around the arc and the rod you dip into it. This part of the tig welding guide covers what gas to run, how much flow to dial in, and how to pick and feed filler rod.

Why Gas Does All the Work in GTAW

Unlike stick or flux-cored processes, TIG has no flux coating and no slag. The tungsten stays solid, the arc is exposed, and the weld pool is naked to the atmosphere, where oxygen, nitrogen, and humidity will oxidize and contaminate it within milliseconds. Shielding gas is the only barrier.

Argon is the default because it is inert, heavier than air so it blankets the puddle rather than drifting away, stable at modest flow, and it provides useful cleaning action on AC. Helium does the opposite job: it ionizes hotter, putting more energy into the arc, which deepens penetration on thick aluminum and speeds work on heavy copper alloys. Helium costs considerably more than argon, so most shops use it only when argon runs out of steam. Argon-helium blends split the difference, giving extra punch while keeping arc starts predictable.

A third category is hydrogen-bearing mixes, usually argon with a few percent hydrogen. These are used almost exclusively on austenitic stainless steel, where the added heat gives smoother, more fluid puddles and deeper penetration. Hydrogen should never be used on carbon steel, where it risks cracking, or on aluminum. Filler and shielding choices are standardized by AWS standards, which is why the codes stamped on your rod and gas cylinder matter.

Flow Rates: Too Little, Too Much, and Just Right

Flow rate is measured in cubic feet per hour (CFH), read off your flowmeter. With a standard number 8 cup, most TIG work sits somewhere around 15 to 25 CFH, and practitioner flow-rate guidance consistently points to matching flow to cup diameter rather than guessing: larger cups need more gas volume, smaller cups need less.

The failure mode people overlook is too much gas. A jet of argon moving faster than the surrounding air creates turbulence at the edge of the stream, and turbulence acts like a vacuum that aspirates air into the shielded zone. The result looks exactly like a gas shortage: porosity, dull gray welds, and discoloration. Too little gas is the more obvious problem, producing open pores and heavy oxide film, especially on stainless where the back side will sugaring if it is not purged as well.

• Symptoms of low flow: porous surface, straw-to-purple heat tint, hissing arc sound.
• Symptoms of excessive flow: wandering arc, swallowed porosity, gas wastage, the same dull finish as low flow.
• Field check: hold a flame or incense stick near the nozzle edge of a running arc; if the flame bends sharply away and flickers, flow is high. Verify the flowmeter itself periodically, since cracked tubing and stuck floats are common.
• Drafts matter: even correct flow fails in an open shop door. Use screens and reposition the part before you lower your helmet.

Gas Lens vs Standard Cups

A standard cup simply dumps gas out of an open nozzle, where the stream tumbles and breaks up within an inch or so. A gas lens replaces that with a stack of fine mesh screens that straighten the flow into a long, laminar column. The payoff is generous: better coverage that lets you run a slightly longer arc for visibility, more forgiving hand position, and often equal or lower flow rates for the same protection. If you weld aluminum or anything positional, a gas lens is the cheapest quality upgrade on the machine.

Picking the Right Filler Metal

The rule is simple: filler should match the base metal family, and be one alloy grade higher when you need corrosion resistance. AWS classifications decode the rod for you, so learn to read them before buying.

Base Metal	Filler	Best For
Carbon steel	ER70S-6	General work; silicon-manganese deoxidizers tolerate mill scale and light surface oil better than ER70S-2
304 stainless	ER308L	Low-carbon grade reduces carbide precipitation in the heat-affected zone
316 stainless	ER316L	Marine and chemical service; molybdenum-bearing alloy matched to the base
Aluminum (general)	ER4043	Flows beautifully, wide puddle, forgiving on cast and sheet work
Aluminum (structural)	ER5356	Higher strength and better anodizing color match, but stiffer and less fluid
Dissimilar joints	Silicon bronze (ERCuSi-A)	Bridging steel to copper or brass at low heat without heavy dilution

Aluminum is where filler choice changes the whole feel of the weld. ER4043 wets out smoothly and is the right default for most hobby work and repairs, while ER5356 gives stronger joints and holds its color after anodizing, at the cost of a fussier puddle. Whatever you choose, aluminum rod must be scrupulously clean, which is exactly why proper aluminum preparation before welding matters as much as the alloy itself. For alloy steels and other high-strength base metals, verify filler compatibility against the base metal specifications before you strike an arc, as covered in our guide to alloy steel welding electrodes.

Filler Diameter and Feeding It Consistently

Match rod diameter to material thickness: roughly 1/16 inch (1.6 mm) for sheet under 1/8 inch, 3/32 inch (2.4 mm) as the everyday middle choice, and 1/8 inch (3.2 mm) for heavier plate. Too large a rod forces you to add amperage you do not want; too small and the rod melts before it reaches the joint, inviting tungsten contact.

Feeding is rhythm, not strength. Rest your feeding hand on a stable surface, keep the rod tip inside the gas shield at all times, and dip it into the leading edge of the puddle on a count of one, withdraw on two, advance on three. Never drag the rod out sideways through the shielded zone, and never feed it into the tungsten. Coordinate that with the foot pedal and travel speed until the motion is automatic, then practice the same sequence out of position using the drills in our all position welding rod guide.

Gas and filler are unglamorous choices made before the arc starts, but they account for most of the difference between a weld that looks professional and one that does not. Set your cylinder, check your flow, choose the rod that matches the metal, and the puddle will tell you the rest.

Setting Up Your Machine: Amperage, AC Balance, Frequency, and Pulse

Most TIG problems that look like “bad technique” are actually bad settings. The machine gives you the numbers to start from; your eyes, watching the puddle, tell you where to adjust. Get the initial dial-in right and your first pass lands in the right neighborhood instead of becoming a guessing game.

Starting Amperage: The 1 Amp Per 0.001 Inch Rule

For mild steel, the classic starting point is roughly 1 amp of output per 0.001 inch of material thickness. A 0.125-inch (1/8″) plate gets about 125 amps as a theoretical ceiling, though in practice you’ll often run a little lower because a TIG puddle spreads heat faster than you expect. Miller’s TIG welding knowledge hub frames the same rule as a starting point to be refined by observed results, and that’s exactly how to treat it.

Material thickness	Starting amperage (mild steel)	Typical filler diameter
22 gauge (0.030″)	25–40 A	0.045″ or 1/16″
16 gauge (0.062″)	50–70 A	1/16″
1/8″ (0.125″)	90–120 A	3/32″
3/16″ (0.187″)	130–170 A	3/32″ or 1/8″
1/4″ (0.250″)	180–220 A	1/8″

Three modifiers matter more than the chart itself:

• Position. Overhead and vertical-up run 10–15% lower than flat, because gravity pulls the puddle.
• Joint type. A lap joint on 1/8″ plate needs less heat than a closed corner that acts as a heat sink.
• Tungsten size. An oversized electrode at low current sputters and wanders; size it to the range you actually run.

DC Setup for Steel and Stainless

Carbon steel and stainless run on DC electrode negative (DCEN): current flows from the workpiece up through the tungsten, putting about two-thirds of the heat into the plate rather than the electrode. That keeps the tungsten cool and the arc concentrated. Set polarity to DCEN, switch high-frequency start on as a start aid only (never as a continuous arc), pre-flow around 1 second, and post-flow between 5 and 10 seconds. Stainless needs no special polarity work; it needs restraint on heat, which is pedal discipline.

AC Balance and Frequency for Aluminum

Aluminum needs alternating current because the oxide layer on top of the metal melts at about 3,700°F while the aluminum beneath melts near 1,220°F. AC alternates polarity each half-cycle: the electrode-negative half drives penetration, and the electrode-positive half blasts the oxide off the surface.

AC balance is the ratio between those two halves. Push toward more cleaning and you get a wider, frosty etched zone and better oxide removal, but shallower penetration and a hotter tungsten. Push toward more penetration and the etch zone narrows, the bead digs deeper, and the tungsten runs cooler. Machines display this two ways: some show “cleaning” percentage, others “penetration” percentage. Either way, a sensible aluminum starting point is roughly 65–75% penetration. If mill scale and oxide weren’t removed mechanically before welding, no balance setting will save the joint; prep comes first, as covered in Aluminum Cleaner for Welding: How to Prep Aluminum Right.

AC frequency controls arc width and focus. Lower frequency (80–100 Hz) gives a wider, softer, more wandering arc with generous cleaning. Higher frequency (120–200 Hz) concentrates the arc into a tighter, more directional cone with a distinct buzzing sound, which helps on fillet welds and corner joints where you direct heat into one side. Most modern inverter machines default around 100–120 Hz, a good all-purpose setting.

Pulse Settings for Thin and Heat-Sensitive Work

Pulsing alternates between a high peak current that melts the puddle and a low background current that lets it partially solidify, cutting total heat input without giving up penetration. On thin sheet, tube, or anything prone to warping, pulse turns a continuous heat source into a series of controlled tacks. Typical starting values are a peak around 60–100% above background, a pulse rate of 1–5 pulses per second for visible puddle control, and a 50% on/off time ratio. Slow the pulse rate until you can actually watch the puddle freeze rhythmically; if you can’t see it, you can’t use it. This style of controlled, low-distortion work is standard in Aerospace TIG Welding: Standards, Techniques, and Training.

Pre-Flow, Post-Flow, and the Foot Pedal

Pre-flow releases gas just before the arc starts so the puddle is shielded from the first millisecond. Post-flow keeps gas flowing after you release the arc, doing two jobs: it shields the still-glowing weld from atmospheric oxygen (which causes the blue and gray discoloration on stainless), and it cools and protects the tungsten, which is at its hottest the instant the arc dies. A rough guide is about 1 second of post-flow per 10 amps, capped around 15–20 seconds; too short invites oxidation, too long just wastes cylinder gas.

The foot pedal is what makes TIG a controlled process rather than a fixed one. Start low to establish a puddle, ramp up to burn through a thick corner, then back off to 40 amps while you chase a thin edge, all inside a single bead. Set the machine slightly higher than your cruising amperage and modulate down with the pedal; that gives you headroom to add heat instantly without stopping. If your machine has only a torch-mounted fingertip control, you lose that finesse, so keep your travel speed variable instead and expect a flatter heat profile.

TIG Welding Technique: Torch Angle, Travel Speed, and Adding Filler

Equipment specs get all the shopping-guide attention, but once the arc starts, none of it saves you if your hands are doing the wrong thing. TIG is a coordination skill: one hand holds the arc, the other feeds the rod, and your eyes read the puddle. The mechanics are well understood, and once you internalize a few geometry rules, good beads become predictable rather than lucky.

Body Position and Hand Support

Start with posture. Sit or stand so the torch travels in a straight line without your arm crossing your body, then plant your torch hand. Most experienced welders rest the side of the hand, wrist, or forearm on the table, workpiece, or a padded rest and pivot from that contact point instead of floating in free air. A rested hand shakes less, and a steady hand keeps arc length consistent. Support the filler hand too, resting it on the joint so the rod tip stays in the puddle zone instead of hunting for it.

Travel direction matters as well. For most flat butt and lap joints, weld forehand: push the puddle forward, torch ahead of the pool, watching the joint ahead of you. Backhand, dragging so the puddle trails, concentrates heat and deepens penetration on heavier material, while forehand spreads heat and improves visibility on thin stock. Learn both, but expect forehand most often as a beginner.

Torch Angle and Arc Length

The most quoted angle in TIG is roughly 10 to 15 degrees from vertical, tilted back in the direction of travel. Straight up tends to shove the shielding gas ahead of the puddle; excessive angle drives the arc sideways and opens the joint unevenly. On fillet welds, keep the torch bisecting the joint, about 45 degrees to each plate, plus that travel tilt.

Arc length is the other half of the geometry. Keep it as short as you can control without touching the tungsten to the puddle, roughly the diameter of the electrode. A short arc keeps the cone narrow and focused, cuts heat spread and warping, and lets the gas column do its job. A long, lazy arc scatters heat, wanders, and invites atmospheric contamination. For a look at how tightly these tolerances are held in demanding work, our Aerospace TIG Welding: Standards, Techniques, and Training guide walks through the technique discipline involved.

Reading the Puddle: Heat, Feed, Move

The puddle is your instrument panel. Its width tells you heat input, its shape tells you whether you have penetration, and its color on stainless tells you if you are overheating. The working rhythm is heat, feed, move:

1. Establish the arc and let the puddle grow to the width you want.
2. Dip the rod tip into the leading edge of the puddle, then withdraw just enough to stop feeding.
3. Advance the torch a hair, then dip again.

Evenly spaced ripples mean the rhythm is holding. That rhythm ties directly to travel speed and amperage: more heat means faster travel and fewer dips, less heat means slower travel and smaller, more frequent ones. If your ripples are uneven, your rhythm changed, not your machine. And feed the rod, never the puddle. Pushing rod into a pool you have not melted yet creates cold, lumpy beads. Melt the puddle, then let it take the rod.

Filler Feeding Methods

• Hand feeding is the default. Pinch the rod between thumb and forefinger, advance a few millimeters per dip, and re-grip as needed. Keep the rod under the gas envelope at all times so the hot tip does not oxidize and drag contamination into the puddle.
• Laying the rod in the joint works for straight beads on thin material: rest the filler in the groove and melt it as you travel. It is fast, forgiving, and very uniform on thin sheet and tubing.
• Walking the cup is the pipe and structural approach. Rest the ceramic cup on the workpiece and rock it in a figure-eight to advance the torch, giving mechanical consistency over long runs.

Match filler diameter to material thickness, and when unsure, err thin, since an oversized rod chills the puddle and drags heat away from the joint. For material-specific selection logic that carries across processes, see our All Position Welding Rod Guide: Types, Uses & Tips.

Using Bead Appearance as Feedback

Every finished bead is a report card. Even, closely spaced ripples mean consistent rhythm. A wandering width means arc length or angle shifted mid-run. A gray, sugared surface means shielding was insufficient. On aluminum, the frosted white band beside the weld is AC cleaning action and should look uniform; patchy frost means balance or travel speed drifted. That surface prep starts before the arc strikes, and our Aluminum Cleaner for Welding: How to Prep Aluminum Right covers degreasing and oxide removal in detail.

Drills to Build Coordination

Do not jump straight to joints. Spend a few sessions on deliberately boring exercises:

1. Puddle control: run a filler-free puddle on flat plate, holding constant width for three inches, then repeat at half speed.
2. Dip rhythm: count dips out loud to set a tempo and try to make every ripple identical.
3. Line tracking: follow a chalk line, watching the leading edge of the puddle rather than the arc.
4. Corners: start and stop at joint intersections, where most real-world defects live.

Twenty focused minutes of these beats an hour of random scrap welding.

Welding Positions and Their Difficulty

Position changes everything, because gravity now works against the puddle. The general beginner progression:

Position	Difficulty	What Changes
Flat (1G/1F)	Easiest	Gravity pulls the puddle into the joint
Horizontal (2G/2F)	Moderate	Puddle sags; use slightly lower amperage
Vertical (3G/3F)	Hard	Vertical-down is fast but shallow; vertical-up penetrates but demands heat control
Overhead (4G/4F)	Hardest	Small beads, short arc, and patience are mandatory

Master flat first, then climb the list. Even professionals restrict rod size and pulse settings overhead to keep the puddle from sagging.

As Miller Electric’s TIG welding knowledge hub puts it, TIG rewards consistency of hand more than machine settings. Keep the arc short, hold your angle, and let the puddle tell you when to move. The rest is repetition.

TIG Welding Different Metals: Steel, Stainless, Aluminum, and More

The same TIG machine that runs a beautiful bead on mild steel can leave you chasing a puddle that refuses to form on aluminum, or a scorched, sugared mess on stainless. Your hand skills did not change; the metal did. Thermal conductivity, melting range, reaction with oxygen at temperature, and compatibility with your filler all shift with the alloy. This part of the tig welding guide is about reading those differences before you strike an arc, because GTAW punishes the assumption that all metals behave alike.

Prep Comes First, Whatever the Metal

Every material below starts with the same four steps, because prep is roughly 70% of the result in TIG work:

• Remove the oxide layer. Aluminum oxide melts near 3,700°F while the aluminum beneath it melts around 1,220°F, so an uncleaned surface gives you a puddle full of floating gray specks. Steel and stainless carry mill scale and oil that cause porosity. Aluminum Cleaner for Welding: How to Prep Aluminum Right covers the dedicated degreasing and brushing routine aluminum demands.
• Degrease. Wipe with acetone or a dedicated solvent, then handle the joint with clean, white cotton gloves so skin oils never reach the joint.
• Fit the joint tight. Gaps force extra filler, extra heat, and distortion. Aim for a hairline fit on butt joints.
• Tack strategically. Four small tacks on a plate joint, more on a pipe circlet, so shrinkage pulls evenly instead of closing the gap on one side.

Carbon Steel: The Forgiving Starting Point

Mild steel is where most welders learn GTAW, and for good reason: it tolerates arc-length wobble, forgives slight contamination, and welds on DC electrode negative (DCEN) with plain argon. A 2% thoriated or lanthanated tungsten works well, ER70S-6 filler covers most sheet and tube because its deoxidizers handle light mill scale, and amperage starts near the classic 1 amp per 0.001 inch of thickness rule. Alloy steels add a wrinkle: higher-carbon and pre-hardened grades can crack in the heat-affected zone without preheat or controlled cooling, which makes filler selection a metallurgical decision rather than a convenience, as explained in Alloy Steel Welding Electrodes: Selection, Use & Safety.

Stainless Steel: Controlling Heat

Stainless also runs on DCEN with argon, but it punishes heat. It distorts readily, work-hardens if you dwell on it, and prolonged exposure above roughly 1,000°F can precipitate chromium carbides at the grain boundaries. That sensitization robs the metal near the weld of its corrosion resistance. The fixes are practical: keep travel moving, use the lowest amperage that still fuses, use a chill block or skip-welding sequence on sheet, and add back purging with argon on pipe root passes so the underside does not oxidize into gray or black “sugared” crust. Full procedure details for code work live in Alloy 20 Welding: Procedures, Filler Metals, and Best Practices. Bead color is a free diagnostic: straw-gold is acceptable, blue-violet means too much heat, and dull gray or crusted means shielding was insufficient.

Aluminum: AC, Oxide, and Heat That Runs Away

Aluminum conducts heat several times faster than steel, so the heat you put into the joint disappears sideways almost immediately. That is why aluminum usually needs higher amperage than the thickness suggests and a faster travel speed: you are heating the whole area quickly enough that the puddle can form, rather than melting a tiny crater that freezes the instant you move. You also switch the machine to AC, where the electrode-positive half blasts oxide off the surface and the electrode-negative half drives penetration. That cleaning action shows as the bright etched zone beside the bead.

Filler splits into two families: ER4043, which flows smoothly, resists cracking, and is the general-purpose choice for non-structural aluminum and castings, and ER5356, which is stronger and preferred for structural and marine work but less forgiving on castings. Scrub with a stainless wire brush reserved only for aluminum, and keep the job moving. Comparing this to wire processes? Aluminum MIG Welding: The Complete Practical Guide shows how much harder aluminum is without that cleaning cycle, while Alloy Wheel Welding: A Comprehensive Guide to Safe and Effective Aluminum Wheel Repair demonstrates the same prep discipline on a common repair job.

Titanium, Copper, Magnesium, and Dissimilar Joints

• Titanium: It needs exceptional cleanliness and full inert shielding because it absorbs oxygen and nitrogen at high temperature, turns brittle, and cracks later under load. In practice: argon on top of the weld, an internal purge on tube, a trailing shield for the cooling bead, and zero exceptions on cleanliness. Demanding aerospace work on this metal is described in Aerospace TIG Welding: Standards, Techniques, and Training.
• Copper and brass: Copper pulls heat even faster than aluminum, so expect maximum amperage, preheat on thick sections, or a silicon bronze filler used at lower heat for brazing-style joints.
• Magnesium: Welds on AC with magnesium-specific filler, but it burns readily and demands strict contamination control and ventilation.
• Dissimilar metals: Choose a filler metallurgically compatible with both sides, or drop to a bronze filler for brazed-style joints, since a rod that suits one alloy may crack the other.

Metal	Polarity	Typical Filler	Key concern
Carbon steel	DCEN	ER70S-6	Clean fit-up
Stainless	DCEN	ER308L / ER316L	Heat input, back purge
Aluminum	AC	ER4043 / ER5356	Oxide removal, fast heat loss
Titanium	DCEN	ERTi / matching grade	Total shielding

Classifications such as ER70S-6, ER308L, and ER4043 are defined by AWS filler metal specifications published by the American Welding Society, and every rod box prints the classification, so you can verify you are holding the right alloy before the arc ever starts.

Common TIG Mistakes, Troubleshooting, and Fixes

Every disappointing TIG weld is telling you something. A gray bead, a mid-run pore, an arc that refuses to hold position: none of these are random. They are symptoms with specific causes, and once you learn to read them, half your frustration disappears. The fastest way to improve is to work the way a repair tech does. Identify the symptom, name the cause, apply the fix, then adjust your setup so it does not happen again.

Tungsten Contamination: The Arc Suddenly Goes Wild

The most common beginner error is touching the tungsten electrode to the workpiece or dipping it into the puddle. The instant that happens, molten metal wicks onto the tip and the arc goes wide, noisy, and unpredictable. The bead underneath usually comes out shallow and lumpy as well, because a contaminated electrode cannot focus an arc.

The fix is simple but annoying: stop, let the joint cool, break or grind off the contaminated tip, and regrind it to a clean point before restarting. Prevention matters more. Ease the amperage up with the foot pedal instead of striking hard, feed the filler rod in from the side so it never crosses the tungsten, and hold an arc length of roughly one electrode diameter. If arc starts are still awkward, practice on scrap plate by striking and lifting the arc hundreds of times before you return to a real joint.

Porosity: Bubbles Trapped in the Weld

Porosity shows up as pinholes or a sponge-like texture, and it is almost always a gas or cleanliness problem. The usual gas suspects are flow that is too low, a draft blowing the shield away, a clogged diffuser or gas lens, the wrong gas, or a leak in the line. The other big contributor is dirty metal: oil, mill scale, paint, and moisture all release gas as they heat. Aluminum is the worst offender, and a proper wipe-down with a dedicated solvent or cleaner is often the missing step, as covered in Aluminum Cleaner for Welding: How to Prep Aluminum Right.

As a starting point, most standard cups run well around 15 to 20 cubic feet per hour of argon, while gas lenses tolerate slightly higher rates because they deliver a smoother column. More flow is not safer: excess flow pulls surrounding air into the shield and creates turbulence, which produces the same porosity you were trying to avoid. If your regulator reads erratically or the needle jumps when you open the valve, sort out your gas hardware before blaming your technique, and Airgas Welding Supplies explains what to look for in regulators and flowmeters. Weld indoors away from fans, and extend post-flow long enough to cover the crater.

Arc Wander and an Unstable Arc

An arc that dances sideways, refuses to start cleanly, or sputters usually traces back to the tungsten: contaminated, incorrectly ground, too blunt, or the wrong type for the job. Other common causes are polarity set backwards, an arc length held too far from the work, and magnetic arc blow from the ground clamp position. Confirm you are running DC electrode negative for steel and stainless and AC for aluminum, regrind the tungsten to the recommended taper, and move the ground clamp so current flows evenly through the joint.

Burn-Through, Lack of Penetration, and Heat Problems

Blowing holes in thin metal means too much amperage, too slow a travel speed, or an arc held too long in one spot. Reduce amperage, shorten the arc, move faster, and use the foot pedal to back off when the puddle gets wide. The opposite problem, a bead sitting on top with no fusion, comes from too little heat, travel that is too fast, or a joint with no bevel and poor fit-up. On thicker material, increase amperage, grind a proper joint bevel, and let the puddle wash into both walls before adding filler.

Bead Appearance Problems

The shape of your bead is direct feedback on your settings and coordination:

• Convex, crowned beads: too little heat, too much filler, or travel that outruns the puddle.
• Undercut: a groove melted into the base metal beside the bead, from excessive amperage, too long an arc, a steep torch angle, or moving too fast without enough filler.
• Uneven ripples: inconsistent travel speed and irregular filler dips. Slow down and match feeding to a steady rhythm.
• Blue, brown, or black tint on stainless: excessive heat input. Heavy tint damages the passive layer and can reduce corrosion resistance, so drop amperage, travel faster, use pulse if available, and improve gas coverage.

Symptom, Cause, Fix at a Glance

Symptom	Most likely cause	Fix
Erratic, wandering arc	Contaminated or badly ground tungsten	Regrind longitudinally, verify polarity and tungsten type
Holes in the bead	Low gas flow, drafts, dirty or wet metal	Check flow, block fans, clean and degrease thoroughly
Blown-through thin sheet	Too many amps, slow travel, long arc	Lower amperage, shorten arc, move faster
Bead sitting on the surface	Too few amps, fast travel, tight fit-up	Raise amperage, bevel the joint, slow down
Undercut at the toes	High amps, steep angle, fast travel	Reduce amperage, soften angle, add filler
Heavy tint on stainless	Excessive heat input	Use pulse, travel faster, extend post-flow

For deeper process fundamentals, Miller Welds’ TIG welding knowledge hub is a solid reference. Work through one symptom at a time, change a single variable, and retest. That is how a difficult weld becomes a repeatable one.

TIG Welding Safety, Practice Plan, and Conclusion

Everything in this guide is useless if you get hurt learning it. TIG looks calm and quiet compared to stick welding, but the arc is still producing intense ultraviolet and infrared radiation, hot metal stays hot longer than you think, and the gases and fumes involved are not harmless. Before you strike your first arc, lock in the safety habits below, then follow the six-week practice plan that turns theory into muscle memory.

Arc Radiation and Eye Protection

The biggest immediate risk to a beginner is the arc itself. UV radiation from a welding arc causes photokeratitis, essentially a sunburn on your corneas, and the pain usually arrives hours after exposure. OSHA requires filter lenses with appropriate shade numbers for arc welding under 29 CFR 1910.252, and notably, gas-shielded arc work on ferrous metals requires a darker filter shade than the same work on nonferrous metals. In practice, most TIG work on steel lands around shade 8 to 12 depending on amperage, while aluminum AC work at high output usually calls for a darker shade.

Cover your skin too: a lightweight cotton or leather jacket, gauntlet gloves, and closed shoes. TIG UV will give you a painful forearm tan in a single session, and synthetic fabrics can melt against the skin.

Fumes, Ventilation, and Respiratory Protection

TIG produces fewer fumes than stick or flux-core processes, but it still produces them, especially when welding coated, plated, or stainless materials. OSHA’s ventilation requirements under OSHA 1910.252 call for mechanical ventilation when welding takes place in spaces of less than 10,000 cubic feet per welder, or in rooms with ceilings lower than 16 feet. A simple box fan blowing across your workspace is not a substitute for proper exhaust.

This matters more than most hobbyists realize. NIOSH has linked manganese exposure in welding fumes to neurological and neurobehavioral effects, and welding in confined spaces significantly raises exposure levels. If you can smell the work, you are breathing it. Use local exhaust ventilation, work outdoors or in a well-drafted shop, and follow an OSHA-compliant respiratory protection program when engineering controls are not enough, as described in 1910.134.

Electrical and Fire Safety

TIG machines run on high open-circuit voltage, so treat leads, torch bodies, and the workpiece with respect: dry hands, no damaged insulation, no cable draped over your shoulder, and a clean, solid ground connection. Replace cracked torch housings rather than taping them.

Fire is the other quiet risk. Sparks and slag can travel, and metal stays hot after the arc stops. OSHA requires a fire watch when appreciable combustible material is within 35 feet of the work, and that fire watch must continue for at least 30 minutes after welding ends. Clear the area, keep an extinguisher within reach, and never weld on containers that previously held flammable material.

A Six-Week Beginner Practice Plan

Deliberate, short sessions beat long, frustrated ones. Aim for three to four sessions a week, 30 to 45 minutes each, on cheap mild steel plate.

Week	Focus	What “good” looks like
1	Setup, arc starts, and dry runs without filler	Consistent arc length, no tungsten touches
2	Beads on flat plate: straight lines, figure-eights, circles	Even width, shallow ripple spacing, pedal control
3	Adding filler: butt joints on 1/8-inch plate	Rhythm of heat, feed, move; no dips into the rod
4	Lap and T-joints, then a simple fillet	Equal legs, no undercut, consistent tie-in
5	Out-of-position work: horizontal and vertical-up	Puddle stays where you put it; see our All Position Welding Rod Guide for filler choices
6	Switch to aluminum on AC, then revisit a failed joint from week 3	Clean, etched surface, no porosity, confident settings

Conclusion: TIG Is a Skill Built on Repetition

The through-line of this TIG welding guide is simple: understand the arc, control the heat, keep everything clean, and protect yourself while you do it. Setup gets you in the right range, technique comes from reading the puddle rather than the clock, and troubleshooting gets faster once you can name the cause behind a symptom. None of it arrives overnight. Progress shows up as smaller mistakes, recovered faster, session after session.

If you want a structured path rather than self-teaching, formal training is worth considering. Programs and certification routes such as an aluminium welding course or AWS Certified Welder testing teach the standards, inspection criteria, and habits that are hard to pick up alone, and AWS standards are the reference most employers actually check. Start with safety, practice with intent, and let the bead tell you what to fix next.

Frequently Asked Questions

Is TIG welding hard to learn?

TIG has a steeper learning curve than MIG or stick welding because you must coordinate your torch hand, filler hand, and foot pedal at the same time. Most people can run a clean bead on flat steel plate after a few focused practice sessions, but consistent out-of-position and thin-material work takes months of deliberate practice. Understanding the theory behind amperage, arc length, and heat control speeds up the learning process dramatically.

Can you TIG weld without filler metal?

Yes. This is called autogenous welding, and it is common on thin sheet metal and certain joint designs where the base metal alone can fill the joint. Autogenous welds are fast and leave minimal cleanup, but they cannot bridge gaps or build up thickness. For most structural or gap-filling work you will still need a separate filler rod.

What is the difference between AC and DC TIG welding?

DC electrode negative concentrates heat into the workpiece and gives deep penetration and a stable arc, which is why it is used for steel and stainless steel. AC alternates polarity every cycle: the electrode-positive half breaks up the tough oxide layer on aluminum, while the electrode-negative half provides penetration. Choosing the wrong mode produces a poor arc and a contaminated weld.

What shielding gas should I use for TIG welding?

Argon is the standard choice for most TIG work because it is affordable and gives good arc stability. Helium and argon-helium blends increase heat input and penetration, which helps on thick aluminum and copper, but they cost more and change arc behavior. Some stainless applications use argon-hydrogen mixes, but those are not suitable for carbon steel or aluminum.

Why does my TIG weld look gray or discolored?

Gray, dull, or heavily tinted weld beads usually mean too much heat input or inadequate shielding gas coverage. On stainless steel, excessive heat tint reduces corrosion resistance. Try reducing amperage, increasing travel speed, improving gas coverage with a gas lens, or increasing post-flow so the cooling weld stays shielded longer.

How much does it cost to start TIG welding?

Entry-level AC/DC TIG machines suitable for hobby work generally cost several hundred dollars, while professional inverter units with advanced features run into the thousands. Budget also for a torch, regulator, tungsten electrodes, filler rods, shielding gas cylinder, gloves, and a quality auto-darkening helmet. Buying a multi-process machine can reduce cost if you also want MIG or stick capability.

Do I need a foot pedal to TIG weld?

A foot pedal is not strictly required, but it makes heat control far easier, especially on thin material and joints where the part heats up as you progress. Many machines also support fingertip amperage controls or on-torch switches for out-of-position work where a pedal is impractical. Beginners should learn with a pedal first whenever the workpiece allows it.

Can TIG welding be used on aluminum?

Yes, TIG is one of the best processes for aluminum because the AC cleaning action breaks up the aluminum oxide layer that would otherwise prevent a sound weld. Aluminum’s high thermal conductivity means you usually need more amperage and a faster travel speed than steel, and fit-up must be tight because the oxide layer melts at a much higher temperature than the metal beneath it.

Is TIG welding dangerous?

All arc welding involves real hazards, and TIG is no exception. The arc emits intense ultraviolet radiation that can cause arc eye and skin burns, welding fumes contain metal oxides that carry health risks, and the process uses electricity and high temperatures near flammable materials. Proper filter lens shade, ventilation or respiratory protection, insulated gloves, and fire precautions reduce these risks substantially.

What tungsten electrode color should I use?

Color identifies the alloying element in the tungsten. Green (pure tungsten) is used for AC aluminum work, red (2% thoriated) is popular for DC steel welding, and gray (ceriated), gold or blue (lanthanated), and other rare-earth blends work well on both AC and DC. Many welders now prefer lanthanated or ceriated electrodes because they perform across a wider range of work without the handling concerns of thoriated tungsten.