[lexxman]

Hi,all. I need a little help, I have to do a certification test on 1/4 and 3/8 aluminum. But I'm having trouble getting penetration in the corner of my fillet. I'm using a miller square wave 250 at 200amp with blueshield 2 gas. And I've going between a 3/32 and a 1/8 tungsten. I tried upping the amps ,but then I blow apart the tungsten or the cup. Top and bottom are good penetration , its the damn corner. just not enough. This the first time in years I've tried to do this and its pissing me off I can't get it.

[MinnesotaDave]

I can't imagine running that at only 200 amps. I'd be at your machines 250 amp max.

1/8" tungsten with balance at about 70% negative should keep the tungsten together.

I doubt a 3/32" tungsten would survive - but I could be wrong.

How do you blow apart a cup?
Only time I've done it was with a gas lens that I didn't put the extra white gasket on (didn't know it needed 2 on that style - my error).
As a result, the cup tightened against the edge of the collet body and broke the end off while welding.

[cj737]

If you are using a Pyrex cup, 200 Amps may be outside it’s tolerance, especially if you are also using a 17- torch. It’s been my experience, to get that corner to penetrate well with thick aluminum, a lower Hz and a slower travel (almost keyholing the bead) to insure you’re a driving the filler in is required. Adding less filler can also help so you don’t cool too quickly the puddle.

[lexxman]

Well to melt or blow apart a cup, it happens when the tungsten balls off to one side and over heats the cup. I'm using a wp20 torch. I've tried using different size cup to the bead smaller. I had a big torch,but I wasn't getting full amps out of it. I've been wanting to try a gas lens, are they better then a standard nozzle ?

[MinnesotaDave]

Well to melt or blow apart a cup, it happens when the tungsten balls off to one side and over heats the cup. I'm using a wp20 torch. I've tried using different size cup to the bead smaller. I had a big torch,but I wasn't getting full amps out of it. I've been wanting to try a gas lens, are they better then a standard nozzle ?

What is your balance set at?
Shielding gas flow rate?
Cup size?
Tungsten stick-out length?

Is blue shield 2 the 50/50 argon/helium mix?

[lexxman]

Balance I'm guessing about70%. my machine only has a cleaning/penetration adjustment1-10. gas flow 15-20 cup size 6-8 depending on space. stick out is not much and yes blueshield 2 is He/Ar mix. And the tungsten are green grounded.

[MinnesotaDave]

Balance I'm guessing about70%. my machine only has a cleaning/penetration adjustment1-10. gas flow 15-20 cup size 6-8 depending on space. stick out is not much and yes blueshield 2 is He/Ar mix. And the tungsten are green grounded.

Syncrowave 250? What number did you turn the cleaning/penetration dial to?

Stick out has to be long enough to get the tip into the corner.

Have you tried more shielding gas flow? Helium is lighter than air.

image.png (272.46 KiB) Viewed 3591 times

[dave powelson]

Balance I'm guessing about70%. my machine only has a cleaning/penetration adjustment1-10. gas flow 15-20 cup size 6-8 depending on space. stick out is not much and yes blueshield 2 is He/Ar mix. And the tungsten are green grounded.

Tapered point with slight blunt on electrode, Lanthiated 2% mucho better---anything but pure (green) tungsten
unless you really like that big melt ball, which UN-focuses the arc, makes it dance and requires much more amps
to do the job as opposed to pointed. The benefits of creating a stiff, focused arc are still not recognized by some.
If you want to get melt waaaaay down in that corner--you need a stiff, focused arc created by tapered point electrode.

For 3/8, some preheat would still be in order, maybe-to get some surface wetting, then the puddle, then the filler addition.
Dwelling on the AL excessively doesn't help.

For comparison with dynasty 350, 180 amps-max, 3/32 pointed electrode and settings tweaked to optimize
for AL welding, using straight Argon, for 3/8 plate fillet welds.

[Arclight Ironworks]

@ lexxman - recommend using max amperage (250A) with your machine for both 1/4in and 3/8in Ally work. GREEN Tungsten with balled end will work; BLUE Tungsten (with micro ball -or- blunt angle profile) is even better.

Lanthanum in the matrix acts as an "emission-enhancing oxide" and improves arc starting/stability ---> 2% La Tungsten has an electron work function (eV) that is ~ 30% lower than pure Tungsten, allowing the electron's to more easily jet from the cathode (Tungsten) across the cold boundary layer (air/plasma interface) to the anode (work piece).

We use 1/8" diameter BLUE Tungsten for 99% of all Aluminum work, regardless of material thickness. Only variable is the tip profile/shape we apply to the Tungsten.

Watch Aaron (6061.com) as he applies PreHeat to thick/thick Aluminum via his TIG torch. This is also a slick technique.

http://www.youtube.com/watch?v=Yq5mrzYCeEI

[MinnesotaDave]

Balance I'm guessing about70%. my machine only has a cleaning/penetration adjustment1-10. gas flow 15-20 cup size 6-8 depending on space. stick out is not much and yes blueshield 2 is He/Ar mix. And the tungsten are green grounded.

Tapered point with slight blunt on electrode, Lanthiated 2% mucho better---anything but pure (green) tungsten
unless you really like that big melt ball, which UN-focuses the arc, makes it dance and requires much more amps
to do the job as opposed to pointed. The benefits of creating a stiff, focused arc are still not recognized by some.
If you want to get melt waaaaay down in that corner--you need a stiff, focused arc created by tapered point electrode.

For 3/8, some preheat would still be in order, maybe-to get some surface wetting, then the puddle, then the filler addition.
Dwelling on the AL excessively doesn't help.

For comparison with dynasty 350, 180 amps-max, 3/32 pointed electrode and settings tweaked to optimize
for AL welding, using straight Argon, for 3/8 plate fillet welds.

Just out of curiosity, and meaning no disrespect, can you explain how tapering an electrode "focuses" an arc when the more an electrode is tapered, the wider and more shallow the penetration?

Also, since the wider the flat spot on the end of a taper, the deeper the penetration, isn't that pretty similar to having a shaped ball on the electrode?

This "flat spot" result occurs due to electricity tending to leave a surface at a right angle to the surface, as I understand it anyway.

image.jpeg (35.3 KiB) Viewed 3571 times

[Arclight Ironworks]

@ MinnesotaDave - that image is a solid descriptor. The origin of that figure is from a 1980 DOE Report authored by Key of EG&G, Anode/Cathode Geometry and Shielding Gas Interrelationships in GTAW.

Note, the base material for all runs was 304SS. Regardless, the same principles ring true for other base metals.

This .pdf should be read by all TIG'rs because it's practical.

[MinnesotaDave]

@ MinnesotaDave - that image is a solid descriptor. The origin of that figure is from a 1980 DOE Report authored by Key of EG&G, Anode/Cathode Geometry and Shielding Gas Interrelationships in GTAW.

Note, the base material for all runs was 304SS. Regardless, the same principles ring true for other base metals.

This .pdf should be read by all TIG'rs because it's practical.

Thanks for the link I don't believe I've seen the full document before.

[TheBeardedWelder]

Great thread!!!

[lexxman]

Balance I'm guessing about70%. my machine only has a cleaning/penetration adjustment1-10. gas flow 15-20 cup size 6-8 depending on space. stick out is not much and yes blueshield 2 is He/Ar mix. And the tungsten are green grounded.

Syncrowave 250? What number did you turn the cleaning/penetration dial to?

Stick out has to be long enough to get the tip into the corner.

Have you tried more shielding gas flow? Helium is lighter than air.

image.png

I think Monday I'll order some blue tungsten and try those.
Yes that's the machine. And yes I set it in the 7-10 range.
I will try some more on Monday, I need to get good penetration while keep weld size to 1/4". Most times the stuff I do is a lot thicker (about an inch or more) so I always pre-heat with a torch. The He/At mixed gas burns hotter then straight Ar.

[dave powelson]

Balance I'm guessing about70%. my machine only has a cleaning/penetration adjustment1-10. gas flow 15-20 cup size 6-8 depending on space. stick out is not much and yes blueshield 2 is He/Ar mix. And the tungsten are green grounded.

Tapered point with slight blunt on electrode, Lanthiated 2% mucho better---anything but pure (green) tungsten
unless you really like that big melt ball, which UN-focuses the arc, makes it dance and requires much more amps
to do the job as opposed to pointed. The benefits of creating a stiff, focused arc are still not recognized by some.
If you want to get melt waaaaay down in that corner--you need a stiff, focused arc created by tapered point electrode.

For 3/8, some preheat would still be in order, maybe-to get some surface wetting, then the puddle, then the filler addition.
Dwelling on the AL excessively doesn't help.

For comparison with dynasty 350, 180 amps-max, 3/32 pointed electrode and settings tweaked to optimize
for AL welding, using straight Argon, for 3/8 plate fillet welds.

Just out of curiosity, and meaning no disrespect, can you explain how tapering an electrode "focuses" an arc when the more an electrode is tapered, the wider and more shallow the penetration?

Also, since the wider the flat spot on the end of a taper, the deeper the penetration, isn't that pretty similar to having a shaped ball on the electrode?

This "flat spot" result occurs due to electricity tending to leave a surface at a right angle to the surface, as I understand it anyway.

-electron flow is on the circumference of the conductor, tapering the OD concentrates this flow, down to the very tip; which also helps in arc initiation. This creates a high current density arc coming off the tip.

-this study with pics--was on straight DC on SS--not AC on AL

-On AC on AL with sharp tungsten, which ideally will only see a slight, tangential melt/blend of the tiny blunt, even after minutes of arc-on---is just a tiny partial sphere at the tapered point--nothing like a pure tungsten melt ball that's larger than the electrode dia. creating a drop on current density at the end, plus allowing for unstable arc that dances all over the place

-"Also, since the wider the flat spot on the end of a taper, the deeper the penetration, isn't that pretty similar to having a shaped ball on the electrode? '

--on AC, AL---I don't think so. For heavy thickness work, I'll use long taper then about 90˚ included angle at the point.
Actually terminating the long taper into a angled point rather than a blunt seems to hold the point longer, as it melts and blends, still getting pretty easy AC starts.

-this biz of arc focusing on AC was first demo'd to myself by Thermal-Arc factory rep. in 1996 with a TA 300 GTSW inverter. TA's point was that it was now possible to get a stiff arc, right down into the corner, seeing wetting and fusion quickly.

-in '97 I setup and showed this to Miller Road Show guys, using their invision machine.
By 2000, Miller had realized that this stiff focused arc on AC was a big deal, especially with inverters and began advertising 'focused arc'.

[MinnesotaDave]

-electron flow is on the circumference of the conductor, tapering the OD concentrates this flow, down to the very tip; which also helps in arc initiation. This creates a high current density arc coming off the tip.

-this study with pics--was on straight DC on SS--not AC on AL

-On AC on AL with sharp tungsten, which ideally will only see a slight, tangential melt/blend of the tiny blunt, even after minutes of arc-on---is just a tiny partial sphere at the tapered point--nothing like a pure tungsten melt ball that's larger than the electrode dia. creating a drop on current density at the end, plus allowing for unstable arc that dances all over the place

-"Also, since the wider the flat spot on the end of a taper, the deeper the penetration, isn't that pretty similar to having a shaped ball on the electrode? '

--on AC, AL---I don't think so. For heavy thickness work, I'll use long taper then about 90˚ included angle at the point.
Actually terminating the long taper into a angled point rather than a blunt seems to hold the point longer, as it melts and blends, still getting pretty easy AC starts.

-this biz of arc focusing on AC was first demo'd to myself by Thermal-Arc factory rep. in 1996 with a TA 300 GTSW inverter. TA's point was that it was now possible to get a stiff arc, right down into the corner, seeing wetting and fusion quickly.

-in '97 I setup and showed this to Miller Road Show guys, using their invision machine.
By 2000, Miller had realized that this stiff focused arc on AC was a big deal, especially with inverters and began advertising 'focused arc'.

Excellent write-up, interesting and very much appreciated.

I see your reference to the "skin effect" of AC current concentrating near the surface of a conductor.
That's a topic I've not considered with aluminum tig and how it may affect the tungsten - I will definitely have to explore this in more detail.

I wonder how your inverter Dynasty and TA 300 results compare for the transformer based Syncrowaves like the OP and myself are running?

I do not think I can get my Syncro 350 to keep a sharpened tungsten on AC.

This weekend I will try max balance (68% neg for my machine) and see at what amps I can keep a tungsten with a sharp tip. Should still be enough cleaning action for new aluminum I would think.

At least it will be interesting and I know what to watch for based on your write-up

[dave powelson]

Excellent write-up, interesting and very much appreciated.

I see your reference to the "skin effect" of AC current concentrating near the surface of a conductor.
That's a topic I've not considered with aluminum tig and how it may affect the tungsten - I will definitely have to explore this in more detail.
*****Since current flow is both ways in AC on the electrode...I suspect that has everything to do with noted effects of pointed tungsten and AC arc tailoring--especially on high end inverters

I wonder how your inverter Dynasty and TA 300 results compare for the transformer based Syncrowaves like the OP and myself are running?
****ummm....weld AL up to 6X faster than with big ole tranny; while achieving more satisfactory results. (I'd previously had 3-300/400 amp trannys); which equates to real savings in power and gas--for myself $2500+/year. TA 300GTSW lasted 16 years; real savings a good $36K---less total new unit cost + accessories/parts/torches of $9500= $26,500 net. Welder, etal came FREE to me.
But I didn't buy inverter for cost savings. I got it for labor/time savings, especially on AL. That old TA grossed in welded value of work for my shop, in excess of $500K. The pulse option on it was a plus for some SS.
The dynasty's ability to infinitely tailor the arc in AC is a hoot. One can use some old school settings, compensate for unwanted effects and still be happy with the result. There's usually about 3-4 ways to tailor the arc and still get decent results. My favorite, by far, on old, dirty, tired AL wrought and especially AL cast is Zank's Krazzee idea of setup, which has been described here and on WW.
The TA had brute power with limited arc tailoring--say it's like a Nascar cup car.
The dynasty has even more power, but can be infinitely adjusted--like a McClaren F1 car. It's an impressive machine that one can continuously learn to do more with.

I do not think I can get my Syncro 350 to keep a sharpened tungsten on AC.

This weekend I will try max balance (68% neg for my machine) and see at what amps I can keep a tungsten with a sharp tip. Should still be enough cleaning action for new aluminum I would think.

Just dial it in for min cleaning action, use anything but pure tungsten. Lan works best on inverters, per Jody Collier and meeself and others. Another mantra of mine 'Massive focused heat succeeds where other methods fail.'
Cleaning action pales compared to focused heat on AL.

At least it will be interesting and I know what to watch for based on your write-up [/quote]

[MinnesotaDave]

Excellent write-up, interesting and very much appreciated.

I see your reference to the "skin effect" of AC current concentrating near the surface of a conductor.
That's a topic I've not considered with aluminum tig and how it may affect the tungsten - I will definitely have to explore this in more detail.
*****Since current flow is both ways in AC on the electrode...I suspect that has everything to do with noted effects of pointed tungsten and AC arc tailoring--especially on high end inverters

I wonder how your inverter Dynasty and TA 300 results compare for the transformer based Syncrowaves like the OP and myself are running?
****ummm....weld AL up to 6X faster than with big ole tranny; while achieving more satisfactory results. (I'd previously had 3-300/400 amp trannys); which equates to real savings in power and gas--for myself $2500+/year. TA 300GTSW lasted 16 years; real savings a good $36K---less total new unit cost + accessories/parts/torches of $9500= $26,500 net. Welder, etal came FREE to me.
But I didn't buy inverter for cost savings. I got it for labor/time savings, especially on AL. That old TA grossed in welded value of work for my shop, in excess of $500K. The pulse option on it was a plus for some SS.
The dynasty's ability to infinitely tailor the arc in AC is a hoot. One can use some old school settings, compensate for unwanted effects and still be happy with the result. There's usually about 3-4 ways to tailor the arc and still get decent results. My favorite, by far, on old, dirty, tired AL wrought and especially AL cast is Zank's Krazzee idea of setup, which has been described here and on WW.
The TA had brute power with limited arc tailoring--say it's like a Nascar cup car.
The dynasty has even more power, but can be infinitely adjusted--like a McClaren F1 car. It's an impressive machine that one can continuously learn to do more with.

I do not think I can get my Syncro 350 to keep a sharpened tungsten on AC.

This weekend I will try max balance (68% neg for my machine) and see at what amps I can keep a tungsten with a sharp tip. Should still be enough cleaning action for new aluminum I would think.

Just dial it in for min cleaning action, use anything but pure tungsten. Lan works best on inverters, per Jody Collier and meeself and others. Another mantra of mine 'Massive focused heat succeeds where other methods fail.'
Cleaning action pales compared to focused heat on AL.

At least it will be interesting and I know what to watch for based on your write-up

[/quote]

I shouldn't have used the word "compare" that way. I meant, how will your results transfer to an old transformer machine that can't tailor like your inverter. Neither my syncrowave nor my Airco 300 (miller 330 abp) will behave the same as your inverter.

Yes, lanthanted is great for inverters, but I'm not running an inverter.

I know inverters have many clear advantages over transformer machines, but if your results don't transfer to an old machine, I don't see how telling the OP to use your methods will work?

Again, I specifically mean no disrespect - you just seem to keep ignoring the fact that sycrowaves are not inverters?

Clearly this is another good excuse for me to buy an AC/DC inverter and do side-by-side comparisons
(I have DC inverters, not too helpful in this case...)

[dave powelson]

Excellent write-up, interesting and very much appreciated.

I see your reference to the "skin effect" of AC current concentrating near the surface of a conductor.
That's a topic I've not considered with aluminum tig and how it may affect the tungsten - I will definitely have to explore this in more detail.
*****Since current flow is both ways in AC on the electrode...I suspect that has everything to do with noted effects of pointed tungsten and AC arc tailoring--especially on high end inverters

I wonder how your inverter Dynasty and TA 300 results compare for the transformer based Syncrowaves like the OP and myself are running?
****ummm....weld AL up to 6X faster than with big ole tranny; while achieving more satisfactory results. (I'd previously had 3-300/400 amp trannys); which equates to real savings in power and gas--for myself $2500+/year. TA 300GTSW lasted 16 years; real savings a good $36K---less total new unit cost + accessories/parts/torches of $9500= $26,500 net. Welder, etal came FREE to me.
But I didn't buy inverter for cost savings. I got it for labor/time savings, especially on AL. That old TA grossed in welded value of work for my shop, in excess of $500K. The pulse option on it was a plus for some SS.
The dynasty's ability to infinitely tailor the arc in AC is a hoot. One can use some old school settings, compensate for unwanted effects and still be happy with the result. There's usually about 3-4 ways to tailor the arc and still get decent results. My favorite, by far, on old, dirty, tired AL wrought and especially AL cast is Zank's Krazzee idea of setup, which has been described here and on WW.
The TA had brute power with limited arc tailoring--say it's like a Nascar cup car.
The dynasty has even more power, but can be infinitely adjusted--like a McClaren F1 car. It's an impressive machine that one can continuously learn to do more with.

I do not think I can get my Syncro 350 to keep a sharpened tungsten on AC.

This weekend I will try max balance (68% neg for my machine) and see at what amps I can keep a tungsten with a sharp tip. Should still be enough cleaning action for new aluminum I would think.

Just dial it in for min cleaning action, use anything but pure tungsten. Lan works best on inverters, per Jody Collier and meeself and others. Another mantra of mine 'Massive focused heat succeeds where other methods fail.'
Cleaning action pales compared to focused heat on AL.

At least it will be interesting and I know what to watch for based on your write-up

I shouldn't have used the word "compare" that way. I meant, how will your results transfer to an old transformer machine that can't tailor like your inverter. Neither my syncrowave nor my Airco 300 (miller 330 abp) will behave the same as your inverter.

Yes, lanthanted is great for inverters, but I'm not running an inverter.

I know inverters have many clear advantages over transformer machines, but if your results don't transfer to an old machine, I don't see how telling the OP to use your methods will work?

***what will help to one extent or another is pointed tungsten--anything but pure, plus setting cleaning action to minimum. Ceriated, lan or thoriated will all hold a point much better than pure. I'm sorry but I thought this was constructive approach to getting more from a tranny, working within its limitations.

Again, I specifically mean no disrespect - you just seem to keep ignoring the fact that sycrowaves are not inverters?

***I'm wholly aware of that and suggested what can help with a tranny, having owned 3 before switching.

Clearly this is another good excuse for me to buy an AC/DC inverter and do side-by-side comparisons
(I have DC inverters, not too helpful in this case...)[/quote]

[5th Street Fab]

Hi,all. I need a little help, I have to do a certification test on 1/4 and 3/8 aluminum. But I'm having trouble getting penetration in the corner of my fillet. I'm using a miller square wave 250 at 200amp with blueshield 2 gas. And I've going between a 3/32 and a 1/8 tungsten. I tried upping the amps ,but then I blow apart the tungsten or the cup. Top and bottom are good penetration , its the damn corner. just not enough. This the first time in years I've tried to do this and its pissing me off I can't get it.

Hey so I use the miller syncrowave 250 all day for aluminium. For 1/4 to 3/8 I'm around 275 amps 1/8" ceriated tungsten. I don't like pure. it seems to weld with an argon helium mix and 310 without. I keep my balance on 6 no higher. The puddle dances and gets unstable when you're higher with a syncrowave. I always ball my Tungsten don't let it ball naturally or you won't get as stable of arc.

I use my torch to preheat like Aaron in that video. You don't want to much preheat or it lowers the strength of aluminium.

When you strike your arc you need to sit there for a few seconds and let everything flow in. I don't add filler until it flows together by itself and wets in. This is where you get your penetration. Once you've got everything established you can move forward make sure it flows with you. If not you need more heat. And make sure you don't add filler until it's flowing smooth and there's no bridge.

These are 1/4" to 3/8"

Sent from my XT1635-01 using Tapatalk

[lexxman]

Well now that I finally got logged back in. Thanks for all the info, I'm hoping to try some test pieces tomorrow. I re do the test on Monday.
@ Guide , thanks . What cup are you using? And yes the arc is unstable, at high amps. I was having trouble getting a smooth arc. I'm so use to weld fast , I have to remind myself to slow down.Your welds look great by the way.

[lexxman]

Hello. Just an update , so I'm sad to say I didn't pass damn restarts. Missed it by a hair, the good news is the boss is going to buy a new machine. Other then the restart,I had good penetration.

[cj737]

This is a great drill to get you over that final hurdle:
https://www.youtube.com/watch?v=OD6alwwP4mU