AL tig welding setup q's

[Zedn]

A question for the ac tig welders.

I'm finally getting an acdc tig!

What tungsten do you use for aluminium with AC tig? I have read articles that all contradict each other. Some say straight tungsten (apparently not good with inverter), some say ceriated, some say thoriated, some say lantharated and also zirconiated (so pretty much all). Whilst saying that they say not to use the others.

I will be mostly welding sheet and flat bar. 1.5mm to 6mm.

I have thoriated so would like to use those, but some articles say they crack.

Looking for real world advise!

[Tonus72]

Hi,

This looks like a handy reference.

Tony


http://www.millerwelds.com/pdf/gtawbook.pdf

[Zedn]

Yes, i have read that. But like i said, it says one thing and other sites say another. Lincoln says Zirconiated or pure tungsten.

Aluminum Welding FAQs

This recommends Thoriated.

TIG welding Aluminum

When i read forum posts it is the same. Old school welders say pure tungsten others say different.

Interested to know what people on here use.

[mickmate]

I use pure but I have an old machine.

[Zedn]

Originally Posted by mickmate

I use pure but I have an old machine.

Thanks, any thoughts on what works with inverter?

I am thinking i will try the thoriated first since i already have them, and then go from there. My only concern is that i have never used AC tig before (only DC) and i want to know the set up works so i can focus on technique.

[Aussie Mike]

Bear in mind I'm no expert here, this is just what I've found.

I used 2% Thoriated (Red) for steel and stainless and sharpen them to a needle point. They seem to give good results.

On Aluminium I used to use Zirconated (White). You use the plain electrode on a bit of scrap before you start and it will form a ball on the end. They worked OK.

More recently I've switched to Ceriated (Grey) for Aluminium. I sharpen them to a pencil point, a bit flattened on the end. I find they give a more concentrated arc that is easier to control.

Cheers

[Zedn]

Thanks mike exactly the info I wanted.

Out of interest have you tried thoriated on aluminium?

[Aussie Mike]

Originally Posted by Zedn

Thanks mike exactly the info I wanted.

Out of interest have you tried thoriated on aluminium?

I think I did ages back when I was still trying to learn how to weld aluminium. So that'll be no gauge as to how well they perform

Cheers

[boxhead]

Mike beat me.
I was going to say pointy red tip on steel, rounded white tip on ally

[750hp]

The two best welders I've seen for automotive art were sharing and comparing their styles a couple of years back on this thread http://www.yellowbullet.com/forum/sh...ad.php?t=97936 I've copied and pasted bits from their posts.

Aaron from 6061 6061.com Intake elbows (site currently down): I usually use 5052 sheet because it is strong and it can be bent/formed without it wanting to crack like 6061. 3003 sheet is soft and easier to form into shapes, but not as rigid.
I use 5356 filler rod despite what some articles say. Most say the 4043 gives a better weld appearance. For me, 5356 seems to shine better. 4043 seems to work better (for me) when welding on cast intakes. I also noticed that hammer-forming a part after welding with 4043, it seemed to want to crack easier.
On my welder, I keep the balance in the 65-68% area, and adjust the positive amperage about 25% lower than the negative. On most welders, adjusting the positive and negative amperage independently isn't an option.
There are also waveform adjustments on the dynasty 350... I leave mine on soft squarewave.
Hertz anywhere above 300. When welding most of my parts, I can get the tip to stay sharp and not ball up with the ceriated tungsten. The high hertz adjustment and adjusting the positive/negative amperage values independently keeps the heat off the tungsten.

Here's an example of his work


John Marcella Marcella Manifolds Home Page : The newer style machines w/ an inverter have a hertz adjustment and with running more hertz it has a tendency to narrow the arc. If all your doing is looking to minimize the white fuzz on the side of the weld you can achieve it by running more negative balance and a higher hertz adjustment. However this is not of any importance when dialing in the correct settings. As far as machine settings it is very difficult to give advise because even though material thickness may be the same the size of the panel and even the thickness of the medal on the table you are welding on all greatly effect how fast the heat is dissipated. I almost never use the pulser, but lately I have been playing around with it and have had pretty good results. (the pulser does not change the look of the weld it just limits the amount of heat that gets put into the part). I personally rarely use 5052, I usually use 4043.
I prefer a different tungsten on different machines because the machine basically preferred different tungsten. On the sincrowaves the green was ok, but if I could get away with it I would use the red. I tried the ceriated that Aaron says he uses but I didn't like it, I ground the rest of the box and used them as scribs. On the aerowave it really likes the lanthenaited, however my dynasty hates it. What I use on my dynasty is the 2% thoraited (red). All the different types of machines will react differently. I use ceriated (orange or grey band) or thoriated (red). I don't really prefer one over the other. I never use green anymore... it seems to get contaminated too easy and the tip doesn't stay as sharp.
John's LS manifold

[Zedn]

Wow. That is some nice fabrication! Thanks for posting that.

Those posts sum it up completely. Everyone likes something different.

Looks to be all about trial and error to come up with what works best for the user and machine.

[mickmate]

I can't weld like that but have worked with a couple of guys that can. They told me not to hold the filler rod right in the joint but to feed it in in a regular rhythm as needed and use it to control the temperature of the weld pool. That would be as well as the pedal of course. It's a trick to get going as there's a lot of noise, magnesium alloys burning etc all going on. The trick I found is to use the amp per thou rule and get right into it with full heat to start the melt of both parts to be welded and then use the filler wire to help control the puddle heat. Also play on some scrap to get your AC balance so it's getting penetration without getting sooty or peppery.

[Tonus72]

My TIG notes from night school...

Edit: PM sent, will email better

[Aussie Mike]

That AC balance I've found is an important setting. It controls the offset between negative and positive in the AC current flow. The positive current flow is what does the cleaning action. It blows the oxide off the surface of the material. The negative current flow provides the heat for weld penetration.

It's also sometimes called "Clean Width" on the dial. You can experiment with it on some scrap material running beads back and forth and see what difference it makes. The more positive you set it you will see the bands at the sides of the weld widen as more of the aluminium is "cleaned". You'll want to set it so you get a nice neat weld with not too much discolouration at the sides from the cleaning action.

Edit* Another thing to remember/observe is the Positive current flow puts more heat into your electrode than the Negative. You will find your electrode will ball up quicker with more positive offset. With some trial and error you will a find a happy medium that works for you.

Cheers

[Zedn]

Picked up some stuff today. The guy at the shop said most people but zirconiated and 5356 rod. I just got 1 tungsten so will try both.

Should I ball the zirconiated on dc first or use it sharp?

I think I will go to ceriated eventually but they didn't have any.

[Zedn]

Also, I have seen a lot of people talking about frequency adjustment 60hz to 300hz. Is this the frequency of alternating current or the pulse frequency.

There is no option to adjust ac frequency on my machine.

Edit: I just looked at some more expensive machines and i see AC frequency is adjustable on these. My machine doesnt have this, does that mean it is 50Hz based on Australia AC supply? Can you still achieve reasonable results without this adjustment?

[Aussie Mike]

Mine has pulse. I use this function a bit. I sometimes dial it back to about 0.5 Hz and use the pulse function like pulsing the foot pedal. You can sync feeding the filler rod in with the high amp cycle of the pulse and make quite a neat looking weld.

Using high freq makes for a more controllable arc. Jodie on welding tips and tricks has a few vids on it.

Cheers

[Andrew429]

Hi Zedn,

I use 2% Lanthanated Tungsten (blue tip), it works well on both AC and DC.
A sharp (with a very small flat spot) 2.4mm 2% lanthanated tungsten works well for me with the following settings: AC Freq: 120 Hz ; AC Balance: 30% + ; by this I mean the machine is DCEN (Negative) 70% of the time and DCEP (Positive) 30% of the time. This is the balance that Mike is referring to.
Frequency adjustment can also help, 60 Hz gives you a wider arc (and can work well on thicker material), 120 Hz gives you a more focused arc, 250 Hz (what my machine is capable of) just gives me a headache from the noise and I don't see much change in the weld bead !
I started out on an old transformer with fixed 60 Hz and 50/50 balance, it will give you more than reasonable results once you get your eye in.
Foot pedal control will be important to you.

[AC-460]

I do it every day of the week...
If you are using AC the best is Zirconiated it has a white end as Boxhead suggested.... grind a small shamfer on the electrode...
only small 1/3 of diameter of electrode ...not a point
Use straight Argon Gas

[Zedn]

Well it was very short lived.

To start with i found the tungsten kept burning up. I was thinking maybe it was too much current or the AC balance was wrong. After about three times with the tungsten burning up, the welder then wouldn't shut of. I tried both foot pedal and torch switch and both did the same thing. Plus it leaked gas inside. Switched to DC and it did the same thing.

Dont know whats wrong with it, but its not working. Its like it is just works at full current or something.

Organising to send it back now. Im going to get my money back and buy a better one.