tech request: school us on tig welding?

That post where the guy hooked up a "weldernator" to a tig gun got me thinkin....

But I don't know much about tig welding, I do know its like torch welding but with sheilding gas and an arc...

So, how bouts a "Tig 101?" Maybe just for steel at first, the basics, and then if someone has energy, elaborate on iron and aluminum?

Thanks,
J

 

TIG is like oxy/acetylene in principle, but is far more controllable IMHO. For the last 8 years I have spent anywhere from 10 to 30 hours a week operating a TIG welder. It is not easy for me to explain TIG technique because it is highly personalized.

Like I mentioned in the MIG post, everybody welds differently. Personally, I see TIG welding almost as a fine Art. You have enough control over heat, travel speed, fill rate, etc, to make your welds like a signature.

There are three of us that do nearly all the Welding at the Company I work for. All three of us can attain the same end result, but I can tell who did the welding on any given Project just by looking at the Beads.

What exactly are you wanting to know?

 

Well... i know everyone welds different... maybe go through your weld... the actions, settings, speed. so not that we will try and copy you.. .but rather we have some written ideas of how we are to proceed.

Thanks
Garth

 

I do almost all my TIGing on Stainless or Aluminum. I can’t tell you much about doing it on regular steel, other than the little bit that I do is done with 316SS filler Rod. We don’t do enough regular steel to warrant keeping filler rod for it.

At its most basic form, you can hook a TIG lead and a bottle of Argon to a Buzzbox and go to town. You will have to scratch-start the Tungsten much like you would a welding rod, but it’s a cheap way to get into TIG welding. You can buy an aftermarket High Frequency unit that will allow you to start an Arc without touching the Tungsten to the steel, but it is not really needed unless you are TIGing Aluminum. If you are planning on welding Aluminum, you will also need an AC/DC buzz box. AC is used for Aluminum and the High Frequency both stabilizes the arc, and helps to clean the surface of the Aluminum as you weld.

The company I work for has three Dedicated TIG machines. They are much more advanced than a Buzzbox and have more switches and gadgets than most people (including myself) know what to do with. They are water cooled, and use a Pedal for fine amperage control. You can use the “High Frequency” just to start the arc on Stainless, or continuously for Aluminum. “Crater fill” backs the amperage off slowly when welding aluminum so it doesn’t leave a pit at the end of each bead from the metal cooling to quickly. I normally just back it off manually with the Pedal myself. There are knobs that control pre and post Flow of the Argon, knobs to adjust the arc Time for even s***ches, and even “Pulse” controls that pulse between higher and lower amperages as you are Welding. This is very handy on thin Aluminum.

Welding Aluminum is not as hard as people think, but for a beginner it is very easy to overheat the bead and have a whole section fall completely out of the metal. It flows a lot different than steel does, the best way I can think to describe the flow characteristic is like Solder. Some people lay the filler on the joint and just weave over it with the Torch. I prefer to “Stab” the filler in and out constantly as I go because it is easier to see what kind of penetration you are getting when your view is not blocked by the Filler rod. Stabbing also gives you the “Stack of Dimes” look, which in my opinion looks better on Aluminum than just a smooth bead.

I also use the Stab technique a on Stainless, Copper, and regular steel, but that is just because I like the look better. The other two TIG welders in the shop generally just lay the rod over the Joint and Weave over it. That gives you a nice smooth bead that looks like Mercury laying in the Joint, but I prefer to be a little more artistic about it.

Sharpening the Tungsten is another thing that is regularly argued about. A sharply ground Tungsten is imperitive for fine work and the way you sharpen it has much to do with the way the Arc behaves while Welding. A long point is best for Sheetmetal because it Spreads the Arc. A short point concentrates the heat much better and is used mainly by Pipefitters and on Heavier Metal because it gives you much more penetration. Personally, I sharpen my Tungstens like a Hollow Ground knife blade. Long angle for most of the Point, with the very tip sharpened at a Shorter angle. This allows me to use 3/32” Tungsten for a wider range of Metal Thickness, plus seems to give me even more control of the Arc at low amperages, like when welding 24g SS.

Aluminum is done with a Balled Tungsten. This is normally done by switching to DC “Electrode positive” long enough to start an arc. This melts the Tungsten and forms a Ball on the tip. You then switch to AC for the actual welding. Unless I am welding thin aluminum, I don’t bother with that method. The Tungsten will ball itself at higher AC amperages like what you would use welding on ¼” plate.

There are a few Basics that need to be learned, but like any other kind of welding there is no replacement for experience and having someone who knows what they’re doing giving you pointers and telling you what you’re doing wrong. Once you get the basics down, it comes to practice, experimenting, and personal preference.

 

how often should I have to sharpen the tungsten?

 

I went and dug out the Welding book I was given while going through my Apprenticeship. Here is a scan of the page that shows the relationship between point style and penetration. Another thing to remember while grinding Tungsten is that the Grinding marks should always be in-line with the Tungsten. If you hold the Tungsten against the grinder Crossways, the grinder marks will cause the Arc to flow off the point erratically. It also creates tiny stress-risers that will cause the Point to break off after a couple of Hot-Cold cycles.

 

Is a "Buzz box" conversion kit available or are you talking do it yourself with purchased parts?

Bill

 

"how often should I have to sharpen the tungsten?"


To achieve professional results, you should sharpen it as soon as you **** it up. I keep about 15 sharp Tungstens at all times and as soon as I get a gob of metal on one, or screw up the point somehow, I change to a fresh one.

It is possible to weld with a screwed up point, but you lose Arc control. The Arc will start to wander around the point, or come off just one side of the point. A fouled Tungsten also Burns the metal that it is fouled with and leaves a smoky residue on the surface of the Weld.

The Vaporised metal that comes off a fouled tip is also what is supposedly causing Parkinson Disease a**** older Welders. I am Union, and get a Labor tribune once a month. for the last year or so, they have been advertising a Cl*** Action Lawsuit involving Metal Fumes and possible Parkinsons Disease a**** career Weldors. I did not apply for inclusion myself, but apparently this is becoming a well do***ented problem. They are now recomending that all weldors use breathing protection, especially when Stick and TIG welding, and Plasma cutting.

 

Thanks!

How much does the tig lead and regulator usually cost?

Tungston tips? Is there a special tool for shaping the tip?

What filler rod is used for general purpose steel work?

Thanks,
J

 

"Is a "Buzz box" conversion kit available or are you talking do it yourself with purchased parts?"


I am sure someone makes a Conversion "Kit", but when we use a buzzbox it is generally on large Jobs where we need more Machines. We have several small Miller Thunderbolts that are kept just for this purpose and we just buy Tig Heads, a spool of Lead, a spool of Hose, and however many Crimp-on Terminals that we need. You will also need an Argon Regulator and the appropriate fittings.

Most of our "field" TIG welding is done with the Miller "MaxStar" TIG/Stick unit. It comes in a plastic Case and the Unit itself is about the size of a VCR. It has a 10' TIG lead, a 10' Ground lead, and a 10' Stick lead. It can be plugged into 115v or 220v because it switches itself internally. The Duty Cycle is 100% at 80amps on 115V, or 100% at 140amps(I think) on 220v. It also has "Touch Start" built in. Instead of scratch starting, you just touch the Tungsten to the work for a second, then the arc starts as you raise it back up off the work.

I normally don't use mine on 220v, 115v will weld anything from 24g to 1/4" Stainless. That pretty much covers the Range of thickness's that I normally encounter. On stick mode, the 220v is needed. 115v will weld with the smallest Rods, but you get a much better quality weld with something like a 3/32" 7018, which requires the use of 220v.

These welders are great as long as you don't plan on welding any Aluminum (no AC), and they are small enough to put in a Truckbox. We have about 8 of them, so I get to keep mine with me most of the time. I also have one of the small 18" or 20" tall Argon Bottles that I carry around with it. It can be filled with a Transfer hose from a large Bottle, and makes my Welding set-up very portable.

I think the MaxStars were running right around $950, last time we bought some. The one I carry is the first one we bought so it has had almost Constant use for the last 3 years with no problems.

 

"How much does the tig lead and regulator usually cost?"


The last time I bought just the TIG head, it was about $60 bucks, and that was for a small one. As for the rest of it I really couldn't tell you, we send apprentices to get the stuff and I have never payed any attention to the reciepts.

"Tungston tips? Is there a special tool for shaping the tip?"

I have found that the best way to sharpen Tungsten is with a Medium grit wheel in a bench grinder. Always point the Tungsten directly towards the wheel, not crossways to the wheel.

"What filler rod is used for general purpose steel work?"

I honestly couldn't tell you. I do very little welding on carbon Steel and what little I do is done with 316 Stainless filler because that is what we have. We do have some filler rod that is very similar to Brazing Rod. It is used mainly when TIGing Galvanized Steel. The melting temperature is much lower, so it doesn't burn off as much of the Zinc. It is still pretty nasty though and if you weld enough galvinized you will get what is called "Metal Fume Fever". In other words, it will make some people puke their Guts out... I get pretty nauseous, but have never puked. It makes your Cigarettes taste like **** too.

 

bftwcs is givin out good info.
I use a Miller Syncrowave 250 at my home shop, yes it is a little overkill ($2900), its a Hopup thang, you all know. Humor aside, a overkill unit will go lower in amp's than the smaller units, at least with Miller equipment.
I do a lot of steel at home and 'luminum at work with a Esab 252, the Esab has fried a few boards and killed the high freak, I work with some novice mechanics, they must have fried them.

One trick that works with me when welding steels (or any DC straight welding), if you need to hit a small or narrow target to lay a bead, I leave a flat on the tip of the electrode. The flat is about a 3rd of the electrode diameter, with a long steep angle, kind of like a sharp pencil that had the lead broken off at the lead edge of the wood. A new electrode works best with this grind, the end is kind of polished.
Try to keep a stone on a bench grinder just for electrodes and try not to grind a rut in the face of the stone.

When I weld sheet steel, at home I only have AK sheetmetal, I will shear off a narrow strip and use it for filler rod. This ensures that the filler alloy is the same as the work, one draw back is that with a filler that is that thin,
is you can not hang too close to the arc with the filler (it melts and rolls on your leg), I hang back 2 inches and stab it in when needed. Also clean the sheared filler strip, no oil or rust, it will pollute the weld.
Brian

 

"bftwcs is givin out good info."

Yeah, good thing TrailerEd is the only person on the HAMB that is in the same Union that I'm in. The Trade Unions still look upon stuff like this as "Trade Secrets", even though the skills are widely known nowadays...

I have been *****ed at before for discussing Welding techniques with other Trades. Doing it on the WWW could get me a real good *** eatin'

 

Damn!!!! Nice post. I now want to build a TIG!! So, can I just buy an old Buzzbox and the TIG parts? I would REALLY be thankfull if you could do a how to on this in-depth or even better a drawing????????????? Puleeeez?

 

miller maxstar tig/stick

 

"how to on this in-depth or even better a drawing"


TIG leads for a Buzzbox are simply a common cable, like what your Stick Stinger is attached to. You just unbolt the leads coming off the Buzzbox, and bolt on the TIG lead. Actually, if you are going to be switching back and forth between Stick and TIG, you would be better off to use Quick Connectors at the Buzzbox. Half a twist, and the cable is off.

The TIG lead has a Gas hose attached to it, usually with wraps of Electrical tape every few inches. The hose runs to your Regulator, and the TIG head will have a Thumb valve to shut off the Gas flow.

Most TIG work is done DCEN, or DC Electrode Negative. That means you are hooking the Stinger to the Ground side of the Buzzbox. Aluminum is done on AC.

Here is a picture of the TIG head. You can see the thumbvalve at the edge of the picture. A dedicated TIG machine uses a Pedal that controls the Gas supply and amperage and does not need the thumbvalve.

 

bftwcs-I'm 36 and I'm tellin'.

 

HaHa... I thought TrailerEd was the only one, besides Weeds, but he's retired anyway.... Ken Tucker that was in my Apprenticeship cl***? Thats the only Tucker I know in Local 36 besides Ed and he doesn't do anything with Cars.

(update)
Well, I read your info and I don't guess I know you. Which shop are you working for?

 

Great post!!
Lots of usefull info. I just picked up a Miller Maxstar 140. i havn't used it yet, but am really looking forward to practicing with it.
thanks for the tech

Rat...

 

the buzzbox conversion has got me interested too! will the amps go low enough on a buzzbox to tig sheetmetal, or is it out of the question due to loss of control? same thing could concievable be done with a small mig welder, no? lower amps, disconnect the wire feed...

if a homemade tig could be done and be "better" for sheetmetal than a mig, i'm all over it!

 

I don't know about doing it with a MIG welder. Never tried it. The Miller "Shopmaster" 300amp MIG has Stick Lugs down at the bottom of the Machine inside a Panel. You can MIG, Stick, or TIG off it, but thats a $5000 welder.

The Miller Thunderbolts I mentioned are just Small, cheap Stick Welders with a Crank on top to control amperage. I don't remember how low they go on Amperage, but its plenty low for Sheetmetal or we wouldn't be using them. For 18g-12g I normally run in the 45-80amp range. The lightest I normally weld is 24g, but thats like trying to weld Foil together and I run 20-25amps. I doubt if any Buzzbox's go that low, but I also doubt that any Car Hobbyists are going to be welding 24g.

 

BTTT

 

Can't do it with Mig. Mig is constant voltage, Tig is constant current.

Chris

 

Thank you for all of this information.

I have a buzz box now and I am interested in
using it for tig. If I understand correctly
you turn on the gas on the gun with your thumb
each p***.

When I use my mig, my current technique for sheet metal is to tack
the joint at the ends and every few inches and then weld
short runs alternating along the joint mostly to avoid
heat build up.

I have welded sheet metal with gas where I tach the end
and then just weld the length of the joint and hammering
if it needs to be flushed out or straightend.

So if the tig method is similar to O/A it sounds like the
similarity is the stabing the filler rod in the puddle.

Question is do you just weld down the joint or do you
tack all over and fill alternatly?

And are you constantly turning the gas on and off like my
mig gun does with the trigger or do you just leave it
going in between welds?
I never thought about it before but is argon harmful to
breathe?

And this high frequency thing you talked about is that
refering to a regular tig machine or another piece of equipment to add to the tig gun when using a buzz box.
If so do you have more info about that?

thanks again for sharing your trade secrets.

 

Thank you, thank you, thank you, thank you

Garth

 

ron covell (professor hammer)

go to ron covell's website and order his video
"basic techniques for working with steel"
he recommends using tig over mig and you get some demonstration of the tig process.... essentially he uses the same technique you use for oxy/acyt - you tack 1 inch apart...then tack between your tacks...keep splitting the difference until your about 1/4 inch apart..then you zip up small areas at a time so as not to over heat - hammer out anything you need to as you go along.......
it's a great video.... i've about worn mine out.....

 

I don't know where you might buy a small invertor for TIG use in the states, but over here in the UK we have this place
http://www.machinemart.co.uk/product.asp?p=010112160&r=2034&g=105

if you take a look you will see a comercially available scratch start TIG, what you call a buz box,this will give you some idea of what to look for.
So Far all the info given is spot on and first rate.
Once you get the hang of using TIG all you need to become proficient is PRACTICE practice and more practice. Get to know your macine and it's settings and it will come to you.It aint rocket science as any welder will tell you, just looks hard to do.
John.

 

the fill rod i would suggest for the majority of basic sheet metal work would be ER70S-2 1/16"

 

this is all really good info-

what i'd like to point out about TIG welding (especially for sheetmetal) is that if it's done right, you'll transfer less heat to the work and avoid warpage that you would get with other welding. like with the quarter panel post, there was a suggestion to not tack the whole panel up- and deal with the warpage as you go......with TIG, this would not be much of a problem. that said- it's really based on you're experience with patch panels and the welding process you are using. TIG can be a real fine, clean process that does not require much filler- as with all welding it takes practice. take it from me.

machines- here in silicon valley there was a guy(seriously it was like a one guy operation) that made small 110 VAC TIG machines for the food industry called HODCO.
These machines were designed for stainless steel and will do about 100 Amps. Real trick little machine.
Be on the lookout for stuff like this- i picked one up for $75 not too long ago- which makes it the worlds cheapest TIG welder- i think.

 

Question is do you just weld down the joint or do you tack all over and fill alternatly?


Personal opinion again. I prefer to control warpage with lots of Tacks, then skipping around and cooling as I weld. Other people just take off welding and worry about the warpage later.

As for the Gas, I generally just leave it on. It only takes a second or two to cool a weld. Is Argon Dangerous? It is heavier than air, so if you got your lungs full of it you would suffocate. They always joke about having to turn people upside down to get the Argon out of their Lungs, I don't know if that works or not

The only time you really have to worry about it is in a confined space. I have worked in confined spaces a couple times and use an Apprentice with an Air Monitering Device to make sure the Argon levels aren't getting dangerous. I have only had the alarm go off once, and after we pointed a small fan into the confined space it kept enough air circulating that it didn't happen again.

The high freq units are built into most TIG welders, or you can buy a seperate unit for your Buzzbox. I have never used the seperate unit, but from what I understand they set on top of the Buzzbox and your leads run through it.

In use, High Freq just jumps High Frequency Sparks across the Gap to start an Arc without actually touching the Tungsten to the work. On Aluminum, High Freq stabalises the AC Arc, plus cleans the surface of the Joint as you Weld. You can actually watch the High Freq sparks blowing the surface oxides off as you weld.