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Question On Aluminum Tig Welding???

Posted: Sat Jun 25, 2016 6:55 pm
by rahtreelimbs
I have some parts that I tack welded for work. Don't know the grade of metal. Welding .125 to .052. I started the weld on the thicker piece and washed it over to the thinner metal. For this application tacks are all that is needed. My question is what causes the black soot. It seems to be more pronounced when the weld is done on the cold side. Thanx in advance. Image

Re: Question On Aluminum Tig Welding???

Posted: Sat Jun 25, 2016 7:50 pm
by exnailpounder
Gas problem....next case :lol:

Re: Question On Aluminum Tig Welding???

Posted: Sat Jun 25, 2016 7:57 pm
by rahtreelimbs
Using a gas lens I had a 3/4 or so stick out to see what I was doing.........gas problem something to think about.

Re: Question On Aluminum Tig Welding???

Posted: Sat Jun 25, 2016 8:32 pm
by RamboBaby
The black soot means that either
A. You dipped yourr tungsten into the puddle
Or
B. You allowed the puddle to grow into the tungsten.
It's one or the other but it's usually B. Usually doesn't cause a problem unless you get a big glob on the tungsten. When that happens it will weld like total crap and you have to change it out. If it's just a little bit on the tungsten then it usually burns of within a few seconds.

Re: Question On Aluminum Tig Welding???

Posted: Sat Jun 25, 2016 9:22 pm
by Farmwelding
exnailpounder wrote:Gas problem....next case :lol:
I have had the same problem with some beads and I found has was the issue. Just turned it up a few cfh.

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 12:19 am
by MinnesotaDave
Man, way more amps and hit it faster.

When I was welding 1/4" to 1/16" I was still over 200 amps with the tungsten pointed almost entirely on the thick piece.

The soot I see is from not forming a good puddle before adding filler.

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 6:28 am
by motox
you need to keep the filler in the shielding gas.
more amps.
craig

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 11:57 am
by rick9345
MinnesotaDave wrote:Man, way more amps and hit it faster.

When I was welding 1/4" to 1/16" I was still over 200 amps with the tungsten pointed almost entirely on the thick piece.

The soot I see is from not forming a good puddle before adding filler.

;) ;) I do that consistently, not waiting for puddle :lol:

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 8:22 pm
by zank
I'm going to be the dissenting voice here and say there is nothing wrong. I get black soot like that outside of the etching zones on a lot of my tacks and that is with a new clean tungsten, before I introduce filler, and I know the gas coverage is good. It seems to depend on what grade I am welding. It happens a lot on 7005. My theory is that it is the high zinc in that grade. It does seem to improve a bit as the metal generally heats up. Maybe I should try pre-heating. The tacks are nice and clean though, so I just wire brush the soot away and start welding.

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 10:10 pm
by LtBadd
if gas coverage was an issue then the tacks would not be so clean, however the tacks are definitely cold

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 10:33 pm
by zank
I should add though that there is no fusion near the root and the joint is just bridged. Is that ok for the application?

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 10:56 pm
by RamboBaby
That's an awfully wide area of cleaning. Where do you have your ac balance set? It almost looks like you're burning back some type of clear coat.

Re: Question On Aluminum Tig Welding???

Posted: Sun Jun 26, 2016 11:15 pm
by MinnesotaDave
RamboBaby wrote:That's an awfully wide area of cleaning. Where do you have your ac balance set? It almost looks like you're burning back some type of clear coat.
If it's not the things you brought up, I usually see a wide cleaning band like that when someone uses too little amperage and "cooks it" waiting for a puddle.

Re: Question On Aluminum Tig Welding???

Posted: Mon Jun 27, 2016 3:24 pm
by rahtreelimbs
zank wrote:I should add though that there is no fusion near the root and the joint is just bridged. Is that ok for the application?
Perfectly fine for thus application.

Re: Question On Aluminum Tig Welding???

Posted: Mon Jun 27, 2016 3:27 pm
by rahtreelimbs
MinnesotaDave wrote:
RamboBaby wrote:That's an awfully wide area of cleaning. Where do you have your ac balance set? It almost looks like you're burning back some type of clear coat.
If it's not the things you brought up, I usually see a wide cleaning band like that when someone uses too little amperage and "cooks it" waiting for a puddle.
Right on the money Dave. You have to take into account my limited tig skills especially on aluminum. When I cut the parts to be welded I cut extra because I knew a burn thru was more than likely......and I did burn thru a few.

Re: Question On Aluminum Tig Welding???

Posted: Thu Jul 07, 2016 3:45 pm
by Modestas97
Hi everyone
Recently buy a tig welding machine, (Stamos s-alu 220 inverter) air cooled.
equipment
equipment
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always wanted to learn welding some aluminum, because in past all my projects end up in need welding aluminum...
So from very first day of trying , I'm getting this mess...aluminum not melting,but just burning
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steel seems to be ok
steel seems to be ok
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tryed different sizes, still got that mess
tryed different sizes, still got that mess
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been welding with mig for a long time,and its looks like gas issue,
using pure argon,the gas bottle is absolutely new,recently buy new one in case it's gas prob.
using pure argon,the gas bottle is absolutely new,recently buy new one in case it's gas prob.
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could it be something wrong with gas adjuster?
I tried different setups frequency and other but still getting same mess,
Or could it be something wrong internally with machine?
I hope you can see all pictures, thank you all

Re: Question On Aluminum Tig Welding???

Posted: Fri Jul 08, 2016 2:14 pm
by noddybrian
Welcome to the forum Modestas97.

Few thing to ask - can you post a picture of what you had the machine set on when attempting aluminum as the controls as set in the picture are totally random & not really suitable.

What thickness aluminum is it / looks thick but cannot advise without knowing.
What is your AC balance set at - in picture it's 50/50 !
Post flow is very low in picture
Can you confirm gas flow at cup - of choice with a " pea shooter " also check for leaks -there appears only one insulator on the gas lens setup in the picture - normally it requires 2 - there is a 1piece made but I never seen them here - only stateside
What size tungsten are you using
In picture your on DC - you are on AC when trying aluminum ?
What amps you trying - if you cannot get a puddle in under 5 seconds it's too low
I realize gas cost is problem here in the UK but those disposable cylinders are primarily intended as a get you out of trouble solution for hobby mig use - while you correctly have pure argon it's for mig welding aluminum normally - it's possible the purity is just good enough to get away with that but tig is less forgiving - could you borrow some a real cylinder of known purity to rule it out.
Sorry I have more questions than answer - but someone here I'm sure will find the solution once we have all the variables.

Re: Question On Aluminum Tig Welding???

Posted: Fri Jul 08, 2016 3:01 pm
by sedanman
If that pucture of the machine is from your aluminum attemps, the machine needs to be set on ac for aluminum.

Re: Question On Aluminum Tig Welding???

Posted: Fri Jul 08, 2016 9:14 pm
by Oscar
To add to the above comments, the black soot facing in one direction means you are welding in a draft/wind. You need to get out of the wind/eliminate all drafts before welding ANYTHING.

Re: Question On Aluminum Tig Welding???

Posted: Fri Jul 08, 2016 10:17 pm
by rahtreelimbs
Always on AC for aluminum.

Re: Question On Aluminum Tig Welding???

Posted: Sat Jul 09, 2016 12:00 pm
by Modestas97
Thank you all for your reply
here is a picture of setup,probably it's a main problem
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I'm using at the moment 2.4mm tungsten
aluminum is 7mm at 30mm
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no gas leaks, plenty gas at cup
first guys can you tell me how to setup correctly, thanks

Re: Question On Aluminum Tig Welding???

Posted: Sat Jul 09, 2016 2:12 pm
by noddybrian
OK - controls still seem rather randomly set but we can make progress now.

You now have 4T selected - are you going to run like this on just the torch switch or are you going to use the pedal ? I ask because it adds another level of complication explaining if we don't need to - if it were me I would run either the pedal or torch switch on 2T also 1-1/4" * 1/4 " will heat up quite quickly as you will need almost maximum amps to get a puddle but will saturate quite quickly - if your learning I would try to find some off cuts of sheet 6 " > 8" square in about 1/8" thickness - this will be easier to learn control on - remember the rough rule of 1amp per thou thickness so 1/4" takes 250 amps in theory - while it's sort of true to get a puddle you would'nt need that once welding.

You say you have plenty of gas ? don't over do it - too much flow is bad - in still air 15 CFH is fine - also remember you don't have separate pre flow on this machine so be aware starting on aluminum it's not very forgiving especially at high amps so use a bit of your post flow to compensate.
You appear to be on AC now - that's correct.
AC balance is on 50 / 50 - you want as marked on your machine about minus 2.5 maybe 3 depending on how clean the metal is.
Post flow is way low - you will be up on the amps so I'd go round 8 seconds but feel free to play till you keep the tungsten silver - also if your attempting 1/4" aluminum your really getting to the edge for 2.4mm tungsten amps - I'd jump up to 1/8" to eliminate another possible issue & thoriated is great on DC for steel or stainless but not the best on AC - I would have to agree with Jody & simplify things with one tungsten for everything ( 2% Lanthanated )
In the original pics you seem to have a foot pedal plugged in but not enabled on the switch - can you confirm this or how you want to run - it matters as I assume though not pictured it's the retarded Chinese toe pedal with the amps pot on the side ? decide if your running short bursts on the torch switch till heat catches up or pedal - if using pedal lower right switch needs to be on and maximum amps needs to be set on pedal pot - if using torch switch the forget left amp knob thats start amps on 4T - set amps on 2nd knob - forget 3rd as it's pulse background and 4th thats end amps 4T. - I would suggest for simplicity use torch switch - set 2nd amp knob to say 180 ish & holding torch at what appears 90 degrees try to get a puddle established & run with it even if you don't add filler yet - if your used to Mig then torch angle was not too important - if you feel you can see what your welding your angle is likely way shallow ! when starting on Tig torch angle is never quite what you think ! play with the amps till you can get a clean silver puddle in hopefully 3 or 4 seconds - up the amps till this happens - but thinner larger pieces of material will make this easier - if you chose to run the pedal - switch lower right switch on & leave pedal pot on max & floor pedal till you get a puddle - then back off as heat builds - once you get this it will all come naturally with seat time especially if you could gas weld to start with - sorry about the ramble but it's way easier to show than tell !

P.S. if you don't mind folks knowing where you are there could even be a member close enough to meet up & figure it out with you - not too many UK active members but worth a try - I've shown a few people the basics when they bought new machines - once you work out how different manufacturers label the controls it's no big deal.

Re: Question On Aluminum Tig Welding???

Posted: Sat Jul 09, 2016 3:41 pm
by Oscar
The main question is: why are you trying to weld 1/4" aluminum with only 83A? Why did you decide on this as the main welding amperage?

To summarize what was already said and my recommendations:
  • Use foot pedal
  • 2T setting
  • Set main welding amperage to 200A
  • Zero-out beginning & ending amps.
  • Pre-flow: 0.5s
  • Post-flow: 7s
  • Cleaning: -3
  • 2% Lanthanated tungsten with a blunt tip and small flat spot

Re: Question On Aluminum Tig Welding???

Posted: Sat Jul 09, 2016 4:11 pm
by Modestas97
We gona try few more attempts,if it's still gona be the same,then gona have to bring it somewhere to welding specialist,

I'm not using pedal at the moment, just want to keep it simple as possible,to get that melting process,
got some different sheet to work with,but still with 2.4mm thungsten, this is my setup at the moment, and once again everything go wrong , hold torch at 90 degrees, space between tungsten and aluminum 2mm,(new tungsten) and just pressed the torch switch , tungsten started just melting...
(p.s going to order different tungsten, as you mentioned those are not really freandly with aluminum)
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different side...
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sorry for really lame question,but is that on top line left side second adjuster for main amperage??

Re: Question On Aluminum Tig Welding???

Posted: Sat Jul 09, 2016 4:16 pm
by Oscar
I still see black soot. Are you welding outdoors?