Introduction: How to Weld - TIG Welding

Picture of How to Weld - TIG Welding

TIG Welding is one type of welding amongst a few choices you have - MIG, Stick, Oxyacetylene, etc.

TIG can be used to weld copper, titanium, even two dissimilar metals, and is handy for making tricky welds (e.g. s-curves, or welds on round things)..

TIG generates heat via an arc of electricity jumping from a (tungsten metal) electrode to the metal surfaces you intend to weld - usually aluminum or steel.

TIG stands for Tungsten Inert Gas, after the tungsten electrode, and the sheath of inert gas (argon or an argon mixture) surrounding it.

Big thanks to Mose O'Griffin, who narrated, taught, and demonstrated.

Also, If you're interested in MIG welding, see this instructable:

Step 1: Choose the Electrode

Picture of Choose the Electrode

Your TIG is likely to have the right electrode in it already.

For aluminum, the best choice is a pure tungsten rod.

You can alternately choose from any number of tungsten alloys (including thoriated tungsten - which is radioactive!) which are uniquely suited to welding particular alloys of metal.

For reference, this example uses the specific alloy 6061 Aluminum (the "steak and potatoes" or "normal" type of aluminum)

Step 2: Grind the Electrode

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Grind the tungsten rod to a point.

Do this, especially if the rod is a brand-new cylinder and doesn't have a pointed or rounded tip yet.

The tip will become rounded due to heat as you weld.

Lincoln recommends a balled tip for AC welding, and a pointed tip for DC welding.

The pointed tip will give a smaller, more directed arc. The arc will tend to dance around, when from a rounded tip.

Step 3: Insert the Electrode Into Its Collet

Picture of Insert the Electrode Into Its Collet

Unscrew the back of the electrode holder, insert the rod, replace back.

The tip of the electrode should be about 1/4" away from the protective sheath, but not much more.

Skip this if you already have your electrode ready.

Shown below are two different types of electrode holders.

Step 4: Choose the Settings

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The typical TIG rig will have three main electricity options - AC, DCEP, and DCEN.

AC is for aluminum - choose "AC".

Set the "Cleaning/Penetrating" setting to the more "Penetrating" side - around 7 on a scale from 1 to 10.

Set the "Air on" to about 5 seconds, if you have the option to do so.
This is the amount of time the gas stays on after the arc stops, to keep your weld from oxidizing/rusting.

Set the "Max Amps" pretty high - perhaps around 250.

For specific settings, check out Miller's settings calculator.

For the curious:

Cleaning/Penetrating is a modification to the positive/negative ratio of the AC that changes the depth of your weld (cleaning is more shallow).

DCEP means "DC, Electrode Postive". This setting is used for balling the tungsten tip, or stick welding.

DCEN means "DC, Electrode Negative", and is for welding steel.

The difference between the two DC settings is the direction the electricity flows - to the metal from the electrode, or to the electrode from the metal. This makes a big difference in the amount of heat the metal absorbs, and the width and depth of the weld.

Step 5: Turn on the Gas

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For aluminum, use pure argon.

For steel, you would use an argon/carbon dioxide mixture.

The gas is important to keep the weld from becoming corroded, as metal will rust (or in the case of aluminum, oxidize) ridiculously quickly at the high temperatures the metal reaches.

Step 6: Prepare Metal and Welding Table

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Some kind of large metallic area is necessary to let electricity flow through your metal. We're using a welding table, purchased for the purpose. Otherwise, a large piece of sheet metal will do perfectly well (just make sure it's flat).

Beauty Tip: Use a wire brush to scrub the surfaces of the metal. It's good practice to keep a dedicated aluminum brush (separate from what you use to clean steel). If you want really nice-looking welds, you can also wipe down the welding rods with acetone.

If you don't care about the way the welds look when finished, don't bother and you'll be fine. However, your welds will be a little weaker and not as pretty.

Clamp your metals so they'll stay where you want them when you weld.

And, if you have the stuff, spray down your welding table with anti-spatter (so if any metal leaks off, it doesn't stick where it lands, which is important if you're trying to keep your surface flat).

Step 7: Get Dressed Up!

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TIG will give you sunburns. TIG will make you see stars (or go blind). TIG will burn your hands.

Use thick leather welding gloves, and a welding helmet, and closed-toe shoes.

To avoid sunburn, wear a long-sleeved shirt or jacket, or a welding coat.

Clean your helmet - the better you can see what you're doing, the better you can weld.

Some people like auto-darkening welding helmets. Others don't like relying on the device's reaction time - you have to invest a lot, to get a good-quality, fast one.

We're using always-dark helmets.

You might use a bright flashlight, if you want to see what you are doing without lifting your helmet.

Step 8: One Last Check

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Hold the electrode in your dominant hand. Make sure it can move freely (untangled, unhampered cord).

Step 9: Weld!

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Hold the electrode about an inch away from the metal. Never touch the metal with the electrode. If you do, molten aluminum will leap onto the electrode. If this happens, stop, turn off the welder, remove the tungsten rod, and grind it down.

Jam down on the foot-pedal to quickly dump a bunch of current and heat into the metal.

The idea is to very quickly heat the metal and start the weld pool. You'll know it when you see it - the metal becomes fluid.

Start on an edge.

When the pool has formed, touch the rod in.

If you heat the metal for too long, it will warp. The longer the metal is heated, the more it will warp.

This is a "tack" weld, to hold the metal piece in place, so you can take off the clamps and do big long bead welds.

Once you have a weld pool started, you can ease off the pedal a little, to control the amount of heat and current being applied to the metal.

Welds shrink as they cool, so you can alternate sides to keep the welds even, and to keep one side of metal from getting too hot and warping. Hot metal can warp a great deal, and if you don't change sides, you might find yourself even 1/4" off of where the metal ought to be.

Step 10: Draw a Bead

After tacking, remove any clamps.

Start a weld pool by jamming down the pedal fast to form a weld pool.

Then lighten up on the pedal, to regulate the current.

If the metal starts to burn/melt away, too much current is being dumped in, back off the foot pedal.
If the metal gets a flaky, but not liquid look to it, put more power in (step on the pedal harder).

To weld aluminum, move the electrode towards the rod, while feeding rod into the pool. The rod should be to the side of the electrode that the weld will form or grow towards. This is known as "leading" the electrode.

To weld steel, the electrode travels first down the weld line, and the rod chases after, "following" the heat.

Step 11: Types of Welds

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Getting the knack of TIG welding is mostly in getting the weld pool to form, at the same time, on both pieces of metal.

The easiest type of weld is the "fillet", two metals jointed at right angles. (The one shown in this instructable).

The next is the "lap" weld, which is two metals resting flat against each other.

Trickier is the "butt" weld, where two metals touch along the edges - it is difficult to keep the electrode traveling in a straight line along the joint, and tough to keep the weld pool going well on both.

Corners require some skill, as the heat is not dissipated evenly.

You can create "cosmetic" or "strength" welds.

Cosmetic welds tend to look more even over long lengths. Create them by making a weld pool, dipping in the rod, and then moving to the next point. Use them on highly visible joints, like on bicycles.

Strength welds are a lot stronger - use them for things that aren't designed to be seen, or are designed for strength rather than beauty. Anything that needs to bear a load (e.g., a gas cannister or propane tank) will have a strength weld. These are the welds where you simply draw the weld pool along continuously, while constantly feeding rod in.


slanwar (author)2017-12-05

I though Tig welding will not use CO2.

Davew62 (author)2015-12-25

Yep, no problem, just use a D rated micro circuit breaker - industrial use type. Also when sharpening tungstens it's better to use a belt sander, just turn it over and sharpen the tungsten on it, it leaves a near perfect finish, obviously if you're welding ally leave the tungsten flat. When welding ally you are effectively reversing the current flow AC instead of DC the electrons flow towards the tungsten and in doing so break the oxidation allowing you to fuse it, Argon simply allows this process to happen, without sheilding the ally would melt away underneath the oxidated layer.

ChristoferS2 (author)Davew622016-12-02

Can you please explain what you mean when you say "you are effectively reversing the current flow AC instead of DC"? AC is alternating current DC is direct current.

irham yahya (author)2016-05-26

why the alumunium very difficult to weld, what else if the surface not be grinding?

there any tips for solve it !!! thanks

Kreat0r (author)2015-12-23

how many amps does a 200Amp need to function ?

I have 40 amps, would that be enough?

steveastrouk (author)2015-03-01

Oh god, DO NOT EVER grind a point on a wheel like that, you are a tiny step from a disaster with an exploding wheel and serious injury.

Kinnishian (author)steveastrouk2015-09-21

Could you do an update about what particularly were the problems with that method of grinding?

For example, is it enough if the OP was standing to the side instead of infront of the grinder? Or were there also issues with how the piece was being held?

Thanks for the elaboration :)

steveastrouk (author)Kinnishian2015-09-22

You never hold something that can slip DOWN between the wheel and the rest. If he slips, the rod will jam into the gap between the rest and the wheel, and the wheel may well explode. The only safe way to do is point up the wheel, on the front, never the edge.

Kinnishian (author)steveastrouk2015-09-22

well, damn, that makes sense when you lay it out actually. I don't suppose I would have considered it, because intuitively putting the rod into the disk, as one might spear something taller than yourself (I hope that made sense), doesn't feel safe. It feels like you're jabbing the wheel and very likely to catch on it. But I can imagine as long as you take the top of the wheel it might be doable and it's essential to not allow the part to fall into the well.

That said with his very aggressive grinder guard I feel like it would be hard to get the right angle. And the rod being so light feels like it won't slip out of our hand.. Yet the consequences of it falling in the wheel well would be terrible.

Kinnishian (author)Kinnishian2015-09-22

My comment sounds snarky where I say "makes sense when you lay it out actually." I did not mean it to sound snarky, I should have added a comma after "out."

PaulC46 (author)2015-09-21

For TIG welding steel, you must use pure argon or an argon / helium mix. Argon / Carbon Dioxide mix works for MIG welding, but will spit and pop and make a total mess of a TIG weld.

frostedlakes (author)2014-10-06

How does argon keep the aluminum from oxidizing?

Kinnishian (author)frostedlakes2015-09-21

I'm not sure if your question is clear enough. the aluminum does oxidize as normal, (i.e, you end up welding a an aluminum plate with a thin oxide layer" but the process with argon doesn't introduce new oxidization when it heats up, because it displaces the oxygen. I don't know how the weld manages to deal with the natural thin layer of oxide that rapidly forms on aluminum, but I believe/assume it just blasts away.

Darkish (author)frostedlakes2015-06-03

Well, oxidizing happens because of oxygen (in the air, in this case) ... if you have argon there, it displaces said oxygen. No oxygen => nothing to oxidize with.

Gumbatron (author)frostedlakes2014-11-14

Aluminium, or any other metal, can only oxidize in the presence of oxygen. Thre argon, being a heavy inert gas, displaces the oxygen from the weld site (until the weld has solidified).

ceo.egal (author)2015-04-08

I am going to be using argon 99.9% for aluminum, sst, and a bronze aka NiBrAl it is a nickel bronze aluminum mixture. It is a specialty metal for ACME propellers and Legend along with OJ. My question pertains to the NiBrAl specifically what is the proper or best gas to be using just out of curiosity previously i have used the Argon.

francis keith yana (author)2015-04-07

AdeelR (author)2015-03-23

best tutorial giving deep insight about TIG process including tungsten preparation and selection of suitable elements. Always thank you for giving special instructions. For more about TIG welding visit

dyethor (author)2014-05-21

Another tip is to have a brush dedicated for stainless. Only a stainless brush should be used on stainless steel. It you use a steel one it will contaminate the SS and it will rust in the spots you used the brush.

dyethor (author)2014-05-21

I like to use either pure argon or an argon helium mix for aluminium. The mix for bigger pieces, The theory is it adds more heat. As others have said you will know if you have CO2 in the mix .

CHEVY6998 (author)2008-01-02

ANY process ofTIG whether it be DC or AC, Steel/Stainless/ or Aluminum should all use only 99.9% purified Argon. 75/25 is not inert and contaminate your welds. This exceptions to this rule and exotic alloys such as Titanium. Ti requires the introduction of Helium and controlled chambering.

I second Chevy6998 I TIG weld for a living, and know for a fact that you only use purified argon for the most common types of welding (Aluminum, Carbon steel, Stainless steel). With the exception of the introduction of helium, hence the reason some people refer to TIG as "heli-arc" (pronounced Heely-ark) If you use an argon/CO2 mixture, you will realize it RIGHT AWAY. Why? Your tungsten will start burning up, turning black, throwing sparks, and "hissing." In other words, you will ruin your Tungsten tip. Also, you need psi to be set at 15-20 psi. 15 will do just fine in most conditions, preventing the waste of gas.

BFeely (author)Fredrick_chilton2014-04-27

Me too. At work we use nothing but argon for our TIG welding. which consists of dissimilar steels joined with 308 stainless.

Thirded. The only gases used in TIG processes are Argon, Helium, and rarely Nitrogen. Argon provides a more stable arc, whereas Helium produces a "hotter" arc. Nitrogen is occasionally used to weld deoxidized copper. Very few TIG processes use C02 as a stabilizing agent, and usually in low ratios (90/10) for exotic metals.

ratz2 (author)JoshuaTerrell2012-03-10

Agree with all above. Never heard of using CO2, except from Joshua above for exotic metals.

monty324 (author)2014-04-15

One inch arc length is mental. I use about one milimeter.

Mig Welder (author)2010-07-27

You don't necessarily have to invest a lot for a good fast AD helmet. I got mine for around $45 and it's great. It has infinite shade adjustment (9-14(or 13?)). You can also change the sensitivity so it doesn't turn on when you look at lights. Finally, you can also change the reaction time (in milliseconds I think) which is nice. . .

Ragnarok-zero (author)Mig Welder2010-09-17

good auto dark tig helmets cost more than mig/mag/mma ones, most cheap helmets won't go to below 20amps many tigs do 5amps a lot of older ones do 10amps mine goes to 3 amps, not many if any cheap masks are suitable for the whole range of a tig welders amps, even a lot of more expensive ones will only go down to 5amp.

7808 (author)Ragnarok-zero2013-11-15

my harbor frieght auto dark darkens at the flick of a lighter, if i welded for a living though id probably invest in a nicer helmet

Ragnarok-zero (author)78082013-11-15

some helmets react to all sorts of things, doesn't mean it's changing light to dark fast enough, if you are using it for tig welding and it isn't rated for it, expect sore eyes and headaches or worse, good tig helmets detect the light as well as the HF start of the welder, tig welding isn't cheap, always use a helmet rated for the job you are doing, if there is one type of kit you don't want to skimp on it's safety gear especially eye protection.

Mig Welder (author)Ragnarok-zero2010-09-17

Is the arc really that incredibly bright at such low amperage?

mfriend1 (author)Mig Welder2012-10-22

its not that bright, its the u.v. radiation it put off when welding with t.i.g.. you should always use a welding helmet even with such low amperage

OVERLOADED (author)Mig Welder2012-02-21

i think it relies on voltage as well, power in wattage is a product of both amps and voltage.

Ragnarok-zero (author)Mig Welder2010-09-18

no the oposite, it's that it's not very bright compared to higher amps the mask doesn't detect the arc and so the mask stays in the light mode does not darken to the proper welding shade, you will see a spec called "minimum tig detection" on some helmets, so for low amps you need one that detects low amps, and they cost a lot more than masks with a higher minimum amp detection that work fine with mig and arc but not the bottom of tig.

2 stroke (author)Ragnarok-zero2010-09-30

i have the flip type for stick welding at home ( its fitted with a shade 11) and my welder is a 70 amp cheap is the shade enough i dont know btw is there gasless tig like gasless mig

snowluck2345 (author)Mig Welder2011-03-27

look on craigslist before going to a store like harborfreight. I got a miller digital elite for $150 dollars on craigslist.

Spudmuffon (author)2013-03-05

I would not say that either of those welds are good the cosmetic weld even if that is what you are doing the puddles are too far apart the weld will break. The strength weld has so many things going on I am not sure what to talk about first off the right side of the weld there was not enough fill at the beginning. Then there was too much heat evidenced by smooth MIG looking weld.Then too much separation between puddles as well as being to cold if it looks like you can pick it with your fingernail or a piece of wire then it is too cold

Spudmuffon (author)2013-03-05

Honestly this gloves and welding leathers are not required a long sleeve non polyester shirt i.e. something that doesnt just melt if caught on fire is just fine. Gloves if I am going to wear a thick glove it is only on the filler rod hand gun control is all with a nice light glove for better feel and control.

Spudmuffon (author)2013-03-05

Aluminum always ALWAYS should be thoroughly cleaned. the wire brush is fine no problem but it needs to be done BEFORE you weld. Aluminum can oxidize very fast and will contaminate the strength and integrity of the weld. Welding aluminum clean just before welding if possible.

Spudmuffon (author)2013-03-05

Ok on the grinding wheel please make sure to 'sweep' across the face of the wheel grooving the wheel not only shortens the life span of your tool but it can be dangerous those wheels spin at a good clip and can shatter if grooved excessively

Spudmuffon (author)2013-03-05

To be fair a "red" tungsten or Thoriated the amount of radioactivity will not harm you in the least you get more radiation smoking a package of cigarets than if you ate the whole pack of tungstens

ratz2 (author)2012-03-10

If you want to see some excellent instructional videos on TIG and other welding check out (search for) wlediingtipsandtricks on YouTube! He also has a website.

Ragnarok-zero (author)2010-09-17

those gloves must be imposable to feed the filler accurately in, get some proper thin tig gloves you don't need those huge things for tig.

ratz2 (author)Ragnarok-zero2012-03-10

You don't want/need stick Arc welding gloves for TIG.
Some people don't even wear gloves if welding for small things, NOT that I would recommend that!
Get gloves that are made for TIG welding.

ratz2 (author)2012-03-10

I don't know if I would wear thick stick welding gloves for TIG.
They make thinner but still protective TIG welding gloves that allow you to feel more as you weld which can be helpful for TIG especially for feeding the rod.

CHEVY6998 (author)2008-01-02

I would strongly suggest a dedicated stainless brush for aluminum. Also one should always care about the way a weld looks and functions. A proper weld will look good by nature. A weak weld is a dangerous one.

stasterisk (author)CHEVY69982008-03-02

did you read the instructable? I only recommend seperate brushes.

ratz2 (author)stasterisk2012-03-10

Not only a dedicated brush for aluminum but a dedicated Stainless Steel brush. Other metal brushes could contaminate the weld.

iMakeItHappen (author)2010-06-19

is it possible to TIG weld w/o the gas? because i know in MIG welding you can use a flux core, and i wanted to know if the same applied here....

I've been wondering this too, but I dont think you can because the tungsten electrode needs a shielding gas to prevent it from being contaminated, and thre wouldn't be enogh shielding without gas.

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