tungsten stability ac tig aluminum problems

[Andrew J 649]

Thanks MMW and ryanjones2150. The story with the cup sizes is long, but basically i have a decent selection for 1/16" and 3/32" but not 1/8". Right now all i have to use with 1/8" tungsten is the standard style (or what i think of as the long style) cup. I was convinced that the right type of tungsten would be found eventually, but that when it was , it would be best in 3/32". Turns out i do think for my air cooled torch & aluminum situation, larger tungsten will be the answer.
The reason i have been experimenting with lower amperages was sort of a take off from what Jody said in one of his videos, which was essentially "take your time" in regards to starting up a weld. Get the material hot, get good cleaning action, and then proceed. So i started slowing down the initial puddling and everything was coming out much better. The welds looked cleaner and shiny-er, and i had absolutely no contamination issues. What also happens at these low amperages is that the tungsten holds its shape much better, and so you have more control. The other thing about low amperages is that there is a lot less ambient heat coming off the weld area, which means (for me anyhow) a much easier time feeding filler rod. I have off-and-on battled with contamination from not properly shielding the working end of the filler rod when welding AL, resulting in big problems. If the amps are low, its quite easy to keep the filler close in, and therefore keeping it in the shielded zone of the gas.
Of course all this lower amperage stuff is only possible with the added helium. That said, even WITH the helium, I'm not going to be able to do the work i need to do on larger sections by this method. Ill need to go up to at least 130-150 amps. So. I loaded up the #17 with a 1/8" 1.5% lanth (which is the biggest i have at the moment as i said before), and set the machine to 140. See the attached photos of the tungsten prep before and after balling, the material (1/4" X 2" 6061... though i mistakenly wrote 1-1/4" for the width) before and after welding, and the final shot of the tungsten after the weld. Not too bad. Still a bit strangely shaped, but not out of control. I think i wrote it in one of the images, but to answer here, the post flow is 8 seconds. Is that too short?
I think the next step would be at minimum, get better alumina cup and gas lens combo for 1/8" and maybe even 5/32" as MMW said. After that, either a bigger air cooled torch as MMW said as well, or just go water cooled and see if that clears things up. I know all of the above will only improve things.
The good news is, the job i was waiting on came in yesterday. So yes, I've got to get things sorted, but at least there's now a little green to go towards the effort.

[ryanjones2150]

Ok, for me, a regular cup is fine for aluminum unless I need to stick out the tungsten and get into a tight spot. It's not like stainless steel in that respect. For post flow, what you need is to keep the gas flowing until the tungsten isn't red hot anymore. It needs to be shiny silver when you're done or it's not enough post flow. A couple of seconds to start while you let the cleaning action work is good, ten is overkill and needless heat input. Once you start, motor on out. If the heat starts getting out of control, taper off, let it cool and start back up. You have the right idea, you're paying attention to the things that need attention paid to. Pretty soon you'll wish all the jobs that slid into your shop were aluminum.

[H80N]

Ok, for me, a regular cup is fine for aluminum unless I need to stick out the tungsten and get into a tight spot. It's not like stainless steel in that respect. For post flow, what you need is to keep the gas flowing until the tungsten isn't red hot anymore. It needs to be shiny silver when you're done or it's not enough post flow. A couple of seconds to start while you let the cleaning action work is good, ten is overkill and needless heat input. Once you start, motor on out. If the heat starts getting out of control, taper off, let it cool and start back up. You have the right idea, you're paying attention to the things that need attention paid to. Pretty soon you'll wish all the jobs that slid into your shop were aluminum.

FWIW..... Post Flow rule of thumb is one second postflow for every 10 amps

so 100amps would be 10 seconds and so on....

[ryanjones2150]

Sounds reasonable to me.

[H80N]

Sounds reasonable to me.

Just a rough guide.....

[Andrew J 649]

Thanks ryanjones2150 and H80N. I think you guys were both on to something more important than i thought it was. My post flow, which i thought was 8 seconds, was actually 5, which going by your rule wouldn't even be close. I bumped it up to double at 10 seconds and the tungsten stays silver. This does seem to help keep the tungsten from eroding prematurely. I also finally got in some 2% lanth, which i'd say is another improvement. Also got in a pyrex cup which allows me to minimize stick out and still see fairly well. When i start doing larger pieces again, which will be soon, i'll know for sure if these changes are enough. Probably still should get a higher amp rated air cooled torch at the least.

[Andrew J 649]

The saga continues.

Since last writing on this subject 10 days ago i've upgraded to a sycnrowave 250 DX. One came up on craigslist here for a good price (serial #LJ260115L) from 2008 i believe. Even had a bottle with it. So I'm a happy guy, but would be even happier if i wasn't still having this tungsten issue, which if anyone can believe it, seems to have gotten worse with the new set up.

So now I'm running this sync 250 with a water cooled #20, and I'm having no luck whatsoever keeping a decent tip. I figured i wouldn't be having any issues, so i started out with the pure argon bottle, 3/32" - 2% lanth and ran a bead on a scrap of 1/4" 6061, not too bad but i noticed right away the same old problem. Checked my gas flow.. about 25 cfm with a good 15 second post flow. Next i tried 1/8"-1.5% lanth on a section of 3/8" angle (this is what the attachment is) with the amps set to 200 and using most of that just to start and backing off a bit to 170-ish after getting going. The new welder has no problem providing the power, and the torch only gets slightly warm, but I'm getting a totally out of control tip and a bit of a crackling sound especially with the pedal down full at 200 at the start up.
Lastly i switched back to my helium argon 50/50 and turned the amperage down around 150. Still pretty out of control on the tip. Im able to make the welds, but that tungsten aint right.
I'm scratching my head over this, as i really thought if i could just cool my torch down, things would only get better.

So, if everyone isn't already bored to tears over this topic by now, i'd appreciate any feedback.

(not sure, but the image looks like its coming up sort of small, so I'm going to crop and re-load)

[MMW]

How does the weld look? The tungsten you show will weld fine for a long time. Yes it does not look perfect but totally acceptable to me for the work I do & able to produce very nice welds.

Try turning the gas down to 15-18 cfh & try that. I never run more than 20 cfh.

Not sure how far you are from me (07853 zip nj) but you are welcome to come over & try my sync 250 to see if it is any different for you? Since it is the second machine I'm sure that is not the issue.

[Andrew J 649]

Thanks MMW, for the input, questions, and offer. If i can't sort this, i may take you up on that.
To answer, here are some comparison welds and tungsten shots.

The first two images are the tungsten shots showing a 2% lanth 3/32" diameter before and after making a weld.
In the before shot you can see the grind and a little ball i put with dcep on brass. In the after shot the end is a huge ball, bigger than the tungsten diameter, and its a bit shorter (as much of it migrated into the weld).

The third and fourth images are welds on two sides of the same T-joint in 1/4" 6061.

The first image shows the weld i just made today with the 250 sync and water-cooled #20 (and the tungsten described above). The gas used is the helium argon 50/50, but turned down to around 18-20 cfm. The amperage was set to 170 and the ac balance backed off to 50% (as i understand it, this should improve tungsten life, right?). The filler used is 3/32" 5356. So, as you can see its not pretty. The tungsten was coming apart as i welded and going into the weld... so, lots of black specks... and it didn't sound so good.

The last image is the other side of that same joint which i welded about two weeks ago with the 180SD and an air-cooled #17. To be fair i was using a larger (1/8") tungsten on that weld. The gas was the same, helium argon 50/50, though i can't recall the cfm. This weld however was made at a lower amperage (130) and i took longer to put it down. As you may recall from earlier in this thread, it was determined that i shouldn't be using this low amp, slow to puddle technique, and i agree. It makes a nice weld here, but the part is small. On larger work, this would not be practical.

[ryanjones2150]

Try not using DCEN to ball the tip. With that 2% lanth you can just roll right out with it and let it ball however it ends up balling. Having that sharp-ish point helps for tacking things up too, just doesn't last long. <br />
<br />
How does your machine do on steel? DCEN?

[Andrew J 649]

Thanks ryanjones2150, I've been balling and leaving sharp. But i figured i should post the balled version so that we could rule that out as the culprit. I sort of imagined that if others saw only a sharp tungsten, most would say to try balling it.
As for the dcen there seems to be no issues. Welds nice and smooth, keeps a good sharp point with ease. Pictured a little sample i just did. two pieces of cold-rolled mild 1/2" x 1/2" with a 1/16" gap between, about 160 amps.

[ryanjones2150]

I don't have the machine you have, but what is your AC balance and frequency set at?

[FusionKing]

I wrote a long post and accidentally lost it...... so I'll be short and blunt. Not to be a jerk, but because I'm out of time and want to help.
Trust me I know what I'm talking about here.
Your tungsten is too blunt. Sharpen it like for stainless and make a small flat on the end.
Use 1/8th and quit using the 3/32.
On your bigger machine you don't need helium. You are wasting money.
You are starting way too slow, and welding too cold and too slow. It's obvious, both in your descriptions and pictures. Jody doesn't mean take forever.
Aluminum is welded HOT and FAST!!! Your settings are about half what they ought to be. Your work is overheated because you are going so slow it is cooking the weld and getting that frosty look.
When you set that big synchrowave on max amps, stomp the pedal, then back off, and go like **** your weld will be nice and shiny. (somebody else already told you)
Also I see a pic where you touched and still went on. Never do that. Stop and clean or you are wasting your time! Both the tungsten and the work.
I also seen a pic of a partially melted cup. Throw it away. Any aluminum on the lens, get it off or throw it away.
One other thing I see that may be a factor. Your material looks nasty. Not sure if you aren't cleaning it enough or what. Switch to new metal. You may freek out how much better you'll get. Otherwise clean it way better.
To weld hot and fast you are gonna have to learn how to feed rod way faster too....or you'll never get better.
Problem with teaching yourself is you get to believing it's this or that. A good teacher would have had you on the right track pretty quickly.
It's you man, not all the settings etc. More practice. Way less jacking around with everything and just weld. Technique trumps equipment everyday.
BTDT, HTH

(P.S. sorry if that sounded rude. Didn't mean it like that. I just realized you have been struggling with this for over a month!!)

[Andrew J 649]

Thanks ryanjones2150. I have varied my AC balance to get the best results between "3" and "8". I was under the impression that towards max penetration (or higher numbers on the dial) is harder on the tungsten, so i guess i mostly have been leaning towards greater cleaning (lower numbers on the dial)... as its tungsten stability/survival that I'm after. I was just looking at the manual which says that "3" is balanced 50/50. Would you recommend this?
As for frequency, i believe my only choices are HF start or HF continuous. Im using HF continuous. Or is there another frequency setting you are referring to. This particular machine doesn't have any of the optional controls that come standard with the 350 LX (which shares the same manual). Attached is a picture of the righthand side controls, or non-controls.

Thanks FusionKing. There is a lot of advise in there. Some of it on the topic of tungsten control etc., a lot of it on aluminum welding in general, and more on, i guess what i'd call general practices. All good advice I'm sure. I'm trying to keep my questions to areas that i think effect the life of the tungsten in the aluminum welding process, but i do realize that you can't isolate one issue, as all of the many parts play into the whole. Type of tungsten, gas coverage, ac balance, material condition/cleanliness, arc length, stick out... the list goes on and on. Clearly I'm a novice compared to many contributors here, but i don't think you need to be a seasoned pro to understand how to keep your tungsten from jumping off into the puddle. Admittedy 100% of my experience has been with mild steel, which I've been welding (and machining) for many years. In those years, and on that material, the rules have been comparatively simple - keep the tungsten sharp, clean, and shielded. I'm just trying to get at the info that I'm lacking in this area. If that puts me in the novice camp, well, then i guess i'll just be getting talked down to by some, but clearly not by all.

[H80N]

Thanks FusionKing. There is a lot of advise in there. Some of it on the topic of tungsten control etc., a lot of it on aluminum welding in general, and more on, i guess what i'd call general practices. All good advice I'm sure. I'm trying to keep my questions to areas that i think effect the life of the tungsten in the aluminum welding process, but i do realize that you can't isolate one issue, as all of the many parts play into the whole. Type of tungsten, gas coverage, ac balance, material condition/cleanliness, arc length, stick out... the list goes on and on. Clearly I'm a novice compared to many contributors here, but i don't think you need to be a seasoned pro to understand how to keep your tungsten from jumping off into the puddle. Admittedy 100% of my experience has been with mild steel, which I've been welding (and machining) for many years. In those years, and on that material, the rules have been comparatively simple - keep the tungsten sharp, clean, and shielded. I'm just trying to get at the info that I'm lacking in this area. If that puts me in the novice camp, well, then i guess i'll just be getting talked down to by some, but clearly not by all.

FusionKing may have sounded a little abrupt... but his advice is excellent and intentions good... do not believe he was talking down....

just trying to give the best advice in the most compact form

He does superb aluminum work.... well worth trying to emulate.... take look at some of his work from his FB page....

https://www.facebook.com/OutBackAlum...=page_internal

It speaks volumes