TIG Welding Aluminum on DC - Page 5

dsmabe · Sat Nov 15, 2014 5:38 pm

soutthpaw wrote:A lot depends on the machine. Many cheaper machines will not maintain an arc on 100% helium. A Dynasty will, my Everlast will support about 60% helium

Id like to try my everlast on straight helium, since I think it is a newer model of what you have.

AKweldshop · Sat Nov 15, 2014 7:12 pm

DeweyO wrote:southpaw - I have a Lincoln Precision Tig 185, square wave , micro start. Not the latest & greatest but sure not Harbor Freight either.

I had a Lincoln Squarewave 175 and tried it on 100% helium.

It actually welded ok.
A little dirtier puddle, but it was stable.

I'd stick to 75/25 Ar/He, or 50/50......

DeweyO · Sun Nov 16, 2014 8:34 pm

AKweldshop -

I have a piece of broken transfer case that I've been experimenting with. I used DCEN and Argon with the dial turned up to the max. 204 amps. In spite of being so dirty it welded pretty well, just drawing a bead. Full penetration and I went fast enough so as not to have it all drop out on me.

Scuba1 · Mon Jan 19, 2015 9:24 pm

Sorry to resurrect this old thread , but no one seems to have a physical idea of why helium seems to cause less warpage in a weld then argon does.
Let me start off to say that my welding abilities were good enough in the construction of semi modern German subs. But I am at the end of the day just a engineer that likes to build stuff and that by default involves machining and welding and a load of other procedures. I am also a commercial diver and that comes into this as well.
I used to cary a small bottle of argon to keep me warm, the reason was that when using the helium oxygen mix that you get to breathe makes you get cold if you use it for keeping the pressure up in your dry suit.
So for that purpose I had a bottle of Argon.
I think by now you know what I am getting at.
If not, let me explain in a simple way. helium does not only transmit electricity pretty bad (hence the uppers on amps needed to weld ) but it also conducts heat very well.
So think of it like hosing down your weld with water while you are welding.
I can math it out for anyone that is interested but if you get the general gist of my ramblings its all you need to know why DC Tig will work in welding no matter what.
Finding the right parameters is the trick..

ATB

Michael

DeweyO · Mon Jan 19, 2015 10:12 pm

By all means, resurrect. All info is welcome. I have no experience using helium, mainly because I never needed to because the only TIG welding I did was on AL. But now I'm in a new place. This puzzle has me really thinking and one thing is for sure - I'm not giving up! After a lot of input and my own research I think DCEN is the way to go, but not by itself. I think placing the casting in a cold CaCl solution and using 4145 filler just might do it, along with a s**tload of amps.

Mon Jan 19, 2015 10:22 pm

"Math it out" for me, Micheal.

I want to see it.

I have access to more helium than almost anyone you'll ever encounter in any welding forum ever.

I like helium for MIG welding, not just tri-mix for stainless, but for carbon-steel welds as well, and the net cost is zero.

I have also used custom helium blends (two flowmeters, one on He, one on Ar, teed together) to great staisfaction.

Your "thermal conduction" idea interests me, but is counterintuitive, so,

Yes, by all means, "math" it out.

Steve S

GreinTime · Mon Jan 19, 2015 11:49 pm

I like using nouns as verbs and adverbs.

Tue Jan 20, 2015 9:55 pm

GreinTime wrote:I like using nouns as verbs and adverbs.

"like"

MinnesotaDave · Tue Jan 20, 2015 10:24 pm

GreinTime wrote:I like using nouns as verbs and adverbs.

In our house, me and the boys call it the "verbanization of a noun."

Tomorrow after work I plan to burger at the local pub.

Joe55 · Tue Feb 10, 2015 7:22 pm

Please HELP!
I have a Maxstar 200 (DC only) welder and I have an aluminum welding project for my race car. I was really excited to see this posting. I tend to agree with those who said that aluminum can be welded with DC as long as it is cleaned properly.
I fabricated an oil pickup (basically a box) from 1/16" aluminum (3003). I need to weld the corners and also a threaded fitting to it. I am an experienced Arc and Mig welder. I am new to TIG welding and to aluminum welding. I tried to test weld some 1/16" aluminum scrap and totally melted it. I had no idea where to start so I started somewhere. Here's my setup: DCEN, 50A, W-20 torch with 3/32" ceriated tungsten sharpened to a blunt angle point, #6 cup, 1/16" 4340 filler rod, Ar/C02 75/25 (from my MIG that's all I have right now), 20 psi. The aluminum is new and I cleaned it with scotch-brite to remove the oxide layer.
Thank you in advance for any help that you can provide! - Joe

P.S. Great website! I've been reading posts and watching videos - very informative!

MinnesotaDave · Wed Feb 11, 2015 11:08 am

Joe55 wrote:Please HELP!
I have a Maxstar 200 (DC only) welder and I have an aluminum welding project for my race car. I was really excited to see this posting. I tend to agree with those who said that aluminum can be welded with DC as long as it is cleaned properly.
I fabricated an oil pickup (basically a box) from 1/16" aluminum (3003). I need to weld the corners and also a threaded fitting to it. I am an experienced Arc and Mig welder. I am new to TIG welding and to aluminum welding. I tried to test weld some 1/16" aluminum scrap and totally melted it. I had no idea where to start so I started somewhere. Here's my setup: DCEN, 50A, W-20 torch with 3/32" ceriated tungsten sharpened to a blunt angle point, #6 cup, 1/16" 4340 filler rod, Ar/C02 75/25 (from my MIG that's all I have right now), 20 psi. The aluminum is new and I cleaned it with scotch-brite to remove the oxide layer.
Thank you in advance for any help that you can provide! - Joe

Joe55 - DCEN is for thick aluminum with 100% helium.

Make no mistake - 75/25 mixed gas will not get it done.

If you want to experiment using 100% argon and DC current, you will need to use DCEP and an 1/8" or bigger tungsten.
DCEP will give you the cleaning action you need, but will be super hot on your tungsten.
Expect to only be able to use about 40-50 amps on an 1/8" tungsten on this polarity.

It is difficult compared to running AC, but I've tried it and it does work on 1/16" aluminum.

rick9345 · Wed Feb 11, 2015 11:22 am

Ar/CO2 mix???????????

Tig really only likes Argon and/or Helium mixes

Like MN Dave, DCEN Helium($) ,big tungsten

After one checks $ Helium/bottle (nearly double flow of Ar to weld) cost,long run maybe invest in AC/DC Tig machine

MinnesotaDave · Wed Feb 11, 2015 2:51 pm

rick9345 wrote:Ar/CO2 mix???????????

Tig really only likes Argon and/or Helium mixes

Like MN Dave, DCEN Helium($) ,big tungsten

After one checks $ Helium/bottle (nearly double flow of Ar to weld) cost,long run maybe invest in AC/DC Tig machine

Big tungsten only for DCEP - it's pretty crazy really, the small ones just explode and/or disintegrate

On DCEN, little tungsten and Helium.

Joe55 · Wed Feb 11, 2015 5:26 pm

Thanks for the help! I will get a tank of Argon for the TIG and put the Ar/CO2 back on the MIG. Then I'll try welding some scrap with 1/8" tungsten. What shape works best on the end of the tungsten for this thin material?

rick9345 · Wed Feb 11, 2015 5:37 pm

I am always mixing up the + & - sorry mn Dave

pgk · Wed Feb 11, 2015 6:23 pm

That's some amazing looking work Roy, years ago I read a few posts on the Hobart forum from a guy with a user name of I believe Pangea. He worked in the aerospace industry and had mentioned that they would spec out DCEN for aluminum quite often, I like many had never heard of this so I contacted him and he set me straight on the process. More than one way to skin a cat.

I have only used DCEN a couple of times on aluminum, and what I found was when it was hot enough to add filler you better be ready to rock and roll. I will have to say your DCEN welds on aluminum look quite a bit better than mine. LOL

Pete

RedIron881 wrote:I've gotten into this debate many times with younger welders right out of school all the way up to welders twice my age and experience. The debate about TIG welding Aluminum on DC. They all say you Can't do it! One thing I've learned in my 15 years in welding is there no such thing as Can't in this industry, you just don't know how. So, figured I'd post something about it and see what all you welders around the world have to say.

Here is the recipe I like to use...

Set machine for welding Steel no more than 190-210 amps regardless of thickness, need a foot pedal for this
Standard or gas lens set up (Gas lens is a bit cleaner but not needed)
2% tungsten works fine 3/32-1/8 sharpened
4043 rod 3/32 (depending on thickness of course)
25-30 psi of Helium (use the helium to bump up the heat not the amps)
5 psi Argon (helps clean up the weld a bit but also not always needed)

A few Pros and Cons

Pros...

-Don't have AC and need to weld aluminum!
-No Preheat for thick parts
-Makes for a great small root pass (preheats for the cap) or one large pass
-Burns much hotter so you can get in and out with minimum warpage but still getting good penetration

Cons...

-Dirty looking weld (until you figure out the right angles). If the material is dirty it really shows in the top and bottom of the weld (as in the photo) but comes right off with a wire brush. This was just handles for a base plate so didn't need to clean up nice.
-Wire will ball up very easy if not added properly. It's not forgiving so add it in the right spot
-Uses a lot of Helium which isn't cheap but if you're welding of a machined billet plate that can't warp too much...

Anyone else ever try this? If not give it a try.

DeweyO · Wed Feb 11, 2015 7:39 pm

Joe -
I'm by no means an expert on the subject but my gut says DCEN TIG on such thin material is going to be a serious challenge unless you have a lot of experience. It's all about the shape of the puddle. DCEN kind of goes straight thru whereas AC is triangular which allows some base metal to stay solid and give support to the molten metal above. This URL is addressed to DC TIG on 2XXX castings but also includes some plate/sheet AL. I found it a fascinating read.

http://www.dtic.mil/dtic/tr/fulltext/u2/613871.pdf

Bill Beauregard · Wed Feb 11, 2015 9:08 pm

My experience with DCEN was on 1/4" T joint. It wasn't as bad as I expected. "A skin" forms, and thickens. It never leaves, so you have to guess about puddle. I found with a good sized puddle, it was possible to shove the filler past the oxide layer which lay as a fragile solid on top. After it cooled I was able to clean it up with a handheld wire brush. No stacks of dimes, but a sound weld.

Bill Beauregard · Wed Feb 11, 2015 11:30 pm

Scuba1 wrote:Sorry to resurrect this old thread , but no one seems to have a physical idea of why helium seems to cause less warpage in a weld then argon does.
Let me start off to say that my welding abilities were good enough in the construction of semi modern German subs. But I am at the end of the day just a engineer that likes to build stuff and that by default involves machining and welding and a load of other procedures. I am also a commercial diver and that comes into this as well.
I used to cary a small bottle of argon to keep me warm, the reason was that when using the helium oxygen mix that you get to breathe makes you get cold if you use it for keeping the pressure up in your dry suit.
So for that purpose I had a bottle of Argon.
I think by now you know what I am getting at.
If not, let me explain in a simple way. helium does not only transmit electricity pretty bad (hence the uppers on amps needed to weld ) but it also conducts heat very well.
So think of it like hosing down your weld with water while you are welding.
I can math it out for anyone that is interested but if you get the general gist of my ramblings its all you need to know why DC Tig will work in welding no matter what.
Finding the right parameters is the trick..

ATB

Michael

Math is nice, but scientific theory is also. If I'm not mistaken helium is the second lightest element. Ain't nobody gonna use hydrogen as shielding gas, it isn't inert. Light being similar to vacuum, intuition would say it would be a good thermal insulator. It seems the opposite is true. These atoms have plenty of room between them to bounce around, and in doing so, transfer heat. Is my logic starting down the path to the answer? Or am i taking the wrong turn?

Bill Beauregard · Wed Feb 11, 2015 11:58 pm

Dewey;
I'm not snubbing you, I can't get a message out for some reason. I'm in Mt Tabor.

Thu Feb 12, 2015 12:05 am

Check your inbox /out box. Won't send if full

Bill Beauregard · Thu Feb 12, 2015 9:03 am

It says 0%, 3%,and 5% full. I'm confused, computer troubles are beyond me. I don't understand, and I'm not even blond.

Bill Beauregard · Thu Feb 12, 2015 9:04 am

It says 0%, 3%,and 5% full. I'm confused, computer troubles are beyond me. I don't understand, and I'm not even blond.

Thu Feb 12, 2015 2:01 pm

Right. That's not the problem. Moving on. Tappatalk or computer browser

soutthpaw · Fri Feb 20, 2015 8:44 am

DCEN. Also had a really strange haze cloud around the puddle that makes it much harder to see than AC argon TIG. Usually the black "soot" that forms on the puddle on DC makes it hard to see the toes of the weld as well no matter how much you clean it. Ar/He mix on AC can give the benefit of both worlds.