Welding Tips and Tricks

So fi tried running some aluminum in DCEN today on some 1/8" at like 120-130 amps with 100% argon. When I did it the aluminum just deflated and sunk in. I know in all the videos, they use helium, but why won't it work with just argon-to much heat directly from DCEN? I don't know maybe one of you does.

What are they teaching you in school?
Gas shield has nothing to do with it.
Aluminium melts at a lot lower temperature than does its oxide layer. You have to remove the oxide layer to weld the virgin aluminium beneath. the EP part of AC GTAW does this. If you use DCEN only, before you melt the oxide layer the virgin aluminium beneath melts and collapses away as you have found. That's why aluminium is tigged AC. You can use DCEP to remove the oxide layer and weld, but your gonna need a 1/4" or bigger electrode to handle the heat.

Coldman wrote:What are they teaching you in school?
Gas shield has nothing to do with it.
Aluminium melts at a lot lower temperature than does its oxide layer. You have to remove the oxide layer to weld the virgin aluminium beneath. the EP part of AC GTAW does this. If you use DCEN only, before you melt the oxide layer the virgin aluminium beneath melts and collapses away as you have found. That's why aluminium is tigged AC. You can use DCEP to remove the oxide layer and weld, but your gonna need a 1/4" or bigger electrode to handle the heat.

Aluminum can, and in certain circumstances is required to be, welded DCEN.

Pure helium is one requirement, for the heat transfer it allows. Surgical cleanliness is the other.

Roy Crumrine (@crummywelding on Instagram and one of the hosts of the WT&T podcast) has experience with it. He has posts here on the subject, under an old username, rediron881.

Here's the topic:
http://forum.weldingtipsandtricks.com/v ... php?t=2002

Steve S

I am aware that with special setup and technique it can be welded DCEN with helium. Highly specialised and kinda rubs the grain up the wrong way a little after all we've been taught. I don't do enough ally and don't keep helium so never gonna experiment. I'll stick with good ole tried and proven square ac with argon.

Coldman wrote:I am aware that with special setup and technique it can be welded DCEN with helium. Highly specialised and kinda rubs the grain up the wrong way a little after all we've been taught. I don't do enough ally and don't keep helium so never gonna experiment. I'll stick with good ole tried and proven square ac with argon.

This brings to mind a maxim about a lifetime of learning possibilities-
"The moment you believe you have all the answers, is the moment you have begun asking all the wrong questions."

And there's one thing I learned early about welding, and that's no one knows everything about welding. It appears to me to be much like the game of chess; easy to learn to play, a lifetime to master.

cj737 wrote:

Coldman wrote:I am aware that with special setup and technique it can be welded DCEN with helium. Highly specialised and kinda rubs the grain up the wrong way a little after all we've been taught. I don't do enough ally and don't keep helium so never gonna experiment. I'll stick with good ole tried and proven square ac with argon.

This brings to mind a maxim about a lifetime of learning possibilities-
"The moment you believe you have all the answers, is the moment you have begun asking all the wrong questions."

And there's one thing I learned early about welding, and that's no one knows everything about welding. It appears to me to be much like the game of chess; easy to learn to play, a lifetime to master.

Amen! I thought I was a great chess player til I played an old-timer down at the VFW...he kicked my ass so bad, every game..and he told me how he did it. He had me beat after my second move

The alternating current is half clean half heat, that's the simple version,

So it removes or more like bombards the surface of the aluminum in order to wreck that oxide layer and expose the jewel within that you are trying to melt, without removing the oxide layer you can pump as much darn heat on it as you want and the moment enough of it is hot enough, it sinks due to gravity, it sucks really......

So anyways, I have heard it can be done but I never did it and never had a need for it but that's probably why it didn't work.

Farmwelding wrote:So fi tried running some aluminum in DCEN today on some 1/8" at like 120-130 amps with 100% argon. When I did it the aluminum just deflated and sunk in. I know in all the videos, they use helium, but why won't it work with just argon-to much heat directly from DCEN? I don't know maybe one of you does.

Pickup a small tank of Helium and maybe try using some thicker aluminum to practise on, dc on aluminum doesn't need much amperage compared to ac. Like the posts above make sure the aluminum is clean, clean clean. I haven't done much aluminum using dc but I did notice that it didn't get that shiny look to it when it was ready to add filler. Good luck

Not to belabor a point, but, I can think of heaps of folks who should learn this technique; all who have a DC TIG only. It provides a much wider reach of welding when you can TIG aluminum. A bottle of Helium is far less expensive than a new AC/DC Inverter. Perhaps those who haven't tried it don't weld aluminum, or have AC in their shop. But lots of folks don't.

As for the OP, who's in school experimenting, this a great place to learn, try and discover. Just gotta follow the rules of 100% Helium with aluminum on DC is all.

I use 50%/50% frequently with my AC box on thick aluminum because I'm amp-limited (200). Cheaper to add He than to buy a new $4k TIG box.

Never welded AL.

But if I had to weld a cracked aluminum tipper`s body. (one of previous job boss wanted somebody to fix his trucks, was welding noob then). You have AC Tig machine.

How would you prepare and weld such task? (Let`s say crack is on the side and at angle 45 dgerees up, you can`t clean inside oxide layer)

I would grind out the crack almost all the way through. Then weld one pass with filler. This first pass will likely be full of porosity and flakes of junk. But you grind out some of that nastyness and do the same thing over again. After one or two or three times most of the oxidation and contaminates will be gone. Then you have a solid base that will allow you to build on till you fill it out.

...Or, you grind it open, preheat with Propane to purge impurities, then clean with Acetone and Stainless brush. Then weld it up. Same process I've used heaps of times welding Jon boats impregnated with alkaline heavy water and mud. Its not fun, its not easy, but its very doable. I have never used He on these jobs, just straight Ar, though I have something coming up I might just whack it with...

Thanks for insight, glad that I didn`t agree back then to use mig (Lincoln magnum I guess) that boss showed me and weld aluminium. Only thing I knew back then, that for AL welding you need round rollers and special liner. I would make a great hole in that tipper.

Hi guys I'm new to the forum but not new to welding. I have been welding for a couple aerospace companies in Southern California. Anyways yes you can weld aluminum in DCEN with 100 percent helium high purity grade not balloon grade. If you know how to weld it it comes out just as nice as ac or even nicer, especially if it is really thick aluminum like 3/8 or thicker.

Gon-Welding951 wrote:Hi guys I'm new to the forum but not new to welding. I have been welding for a couple aerospace companies in Southern California. Anyways yes you can weld aluminum in DCEN with 100 percent helium high purity grade not balloon grade. If you know how to weld it it comes out just as nice as ac or even nicer, especially if it is really thick aluminum like 3/8 or thicker.

Welcome to the forum, is this process used at your facility? Got any photos you can post?

LtBadd wrote:

Gon-Welding951 wrote:Hi guys I'm new to the forum but not new to welding. I have been welding for a couple aerospace companies in Southern California. Anyways yes you can weld aluminum in DCEN with 100 percent helium high purity grade not balloon grade. If you know how to weld it it comes out just as nice as ac or even nicer, especially if it is really thick aluminum like 3/8 or thicker.

Welcome to the forum, is this process used at your facility? Got any photos you can post?

Yeah! Pictures or it didn't happen....

Haha yeah here are a few jobs I did with DCEN, it's my first time posting pics. so hopefully they show up. And yes where I currently work we use DCEN.

You and the shop you work at rock. You've set the benchmark very high.


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Now THAT is aluminum welding! One question..what are those?

Pretty darn cool Gon-Welding951

Since the amperage is dramatically less with DCEN on aluminum, mind telling what amps (approximately) those were welded at for reference?

Very nice work

Thank you guys. Usually on 1/4- 3/8 around 205 amps anything thicker like 1/2- 2" 210- 250 amps. My favorite set up is a 3/32 red band tungsten #7 gas lens and 40- 60 cfh on helium.

What is the max thickness of Al you can weld with 160amps DC? (curious `bout this machine Migatronic Rallymig 161i)

Gon-Welding951 wrote:Thank you guys. Usually on 1/4- 3/8 around 205 amps anything thicker like 1/2- 2" 210- 250 amps. My favorite set up is a 3/32 red band tungsten #7 gas lens and 40- 60 cfh on helium.

Thanks for the info - pretty cool process