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Why can I never get a puddle on aluminum tubing?

Posted: Sat Dec 19, 2015 11:27 pm
by Goldhawg
Rookie to Tig, and I'm following Jody each week. I can work it pretty well on my flat 5" practice plates, but when it comes to tubing, I can never get it to develop a puddle. So I'm working with 14 gauge aluminum tubing, and today I cranked the Miller 210 to 100A and 65% balance. The tungsten tip has a dull point which does develop a slight ball, and using 20 CFM argon. Previously I had been running 75A w/no joy, so today thought I'd try 100A, but same result. To prep the tubing I have sanded, brushed w/SS brush and then wiped w/Acetone. But still looks like it has contamination. Also, I can't seem to get a stable arc on start up especially; it really wants to wander even though my torch angle is good. Thoughts?

Re: Why can I never get a puddle on aluminum tubing?

Posted: Sat Dec 19, 2015 11:57 pm
by LtBadd
Goldhawg wrote:Rookie to Tig, and I'm following Jody each week. I can work it pretty well on my flat 5" practice plates, but when it comes to tubing, I can never get it to develop a puddle. So I'm working with 14 gauge aluminum tubing, and today I cranked the Miller 210 to 100A and 65% balance. The tungsten tip has a dull point which does develop a slight ball, and using 20 CFM argon. Previously I had been running 75A w/no joy, so today thought I'd try 100A, but same result. To prep the tubing I have sanded, brushed w/SS brush and then wiped w/Acetone. But still looks like it has contamination. Also, I can't seem to get a stable arc on start up especially; it really wants to wander even though my torch angle is good. Thoughts?
if that's a solid block of Al the tube is setting on then that is the problem. The block would need to be pre-heated, this is a thick to thin weld joint.

Re: Why can I never get a puddle on aluminum tubing?

Posted: Sat Dec 19, 2015 11:59 pm
by MinnesotaDave
Turn your machine all the way up. That solid block is a huge heat sink.

Unless the pic is an optical illusion, that tube is much thicker than 14gauge.

Re: Why can I never get a puddle on aluminum tubing?

Posted: Sun Dec 20, 2015 6:16 am
by motox
listen to dave and crank your machine all the way up
and try a starting a puddle away from the edge
without the tubing on it first.
craig

Re: Why can I never get a puddle on aluminum tubing?

Posted: Sun Dec 20, 2015 6:35 am
by Goldhawg
Guys, the rectangular piece is also hollow; only slightly thicker than the piece I'm trying to tack it to.

Re: Why can I never get a puddle on aluminum tubing?

Posted: Sun Dec 20, 2015 8:23 am
by LtBadd
Goldhawg wrote:Guys, the rectangular piece is also hollow; only slightly thicker than the piece I'm trying to tack it to.
It would be helpful to know what machine you're using, and the settings, shielding gas, and tungsten (ie, pure, 2%, etc)

Can you start an arc on different material and it's good? If not then check for a compromise in the shielding gas connections and hose

Re: Why can I never get a puddle on aluminum tubing?

Posted: Sun Dec 20, 2015 9:39 am
by big gear head
What is the tube made of? Is it 6061, 7075, 3003?

Re: Why can I never get a puddle on aluminum tubing?

Posted: Sun Dec 20, 2015 12:01 pm
by Oscar
Assuming that's a weldable grade of aluminum, crank it all the way up. Mash the pedal until you can manage to blow a huge giant hole practically instantly. Reduce amperage by 15A. Repeat until you don't blow a hole, but get a good large puddle. Right about's there your amperage setting will be near correct. I remember seeing black crud like that with wayyyy too little amperage. Put on your big boy shoes and get that puddle going FAST.

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 9:22 am
by GFab70
I don't use sandpaper, I use a scotchbrite. They don't leave as much debris behind.

I am guessing you are trying to weld the round to the square, if so get a long clamp and tighten them together after cleaning. Then hook ground to clamp. Set the work on a 45° angle to help "flow" the puddle between both parts. Concentrate heat on the thicker or heavier piece until your puddle forms. Don't be in a hurry, let it heat and if you don't get a puddle in 5-15 seconds turn your heat up. Using a foot control is easiest. Keep your cleaning action on the low side and your frequency around 100 to help focus the arc. When a puddle forms the tiniest bit add filler rod and "flow" it to other half of part. In a corner joint you often will have to move torch between both weld pieces all the way around to keep puddle flowing where ya want it.

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Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 1:03 pm
by Cricket
Just to verify... you use 100% argon and NOT C25 right?

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 5:37 pm
by Oscar
GFab70 wrote: let it heat and if you don't get a puddle in 5-15 seconds turn your heat up.
Respectfully disagree 100%. If the parts are not "large", you end up heating the whole thing, and before you know it, the whole thing will become a glob of molten metal. I feel most will agree that you need to enough power to form a puddle in 2-4 seconds due to the high thermal conductivity of aluminum compared to other metals/steels. A higher-than-usual initial current will force you to travel a bit faster to out-run the heat-build up, but hey, if it were easy everybody would do it.

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 5:57 pm
by MosquitoMoto
My 2 cents -

When I first started out, in the name of caution I used to select relatively low amps for my aluminium and I'd sit there for 10 seconds waiting for a puddle to form...wasting argon and heating the hell out of the part, the bench and the whole suburb. Then when heat finally reached 'critical mass' the whole thing would become grilled cheese.

I'm with Oscar - get your amps up. If you are not seeing a puddle in 3 seconds or less, crank them up some more. Getting your local area very hot very quickly, then backing off, beats the hell out of slowly I heating the whole part and running a salvage operation from there on in.



Kym

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 7:26 pm
by MinnesotaDave
GFab70 wrote: I am guessing you are trying to weld the round to the square, if so get a long clamp and tighten them together after cleaning. Then hook ground to clamp. Set the work on a 45° angle to help "flow" the puddle between both parts. Concentrate heat on the thicker or heavier piece until your puddle forms. Don't be in a hurry, let it heat and if you don't get a puddle in 5-15 seconds turn your heat up. Using a foot control is easiest. Keep your cleaning action on the low side and your frequency around 100 to help focus the arc. When a puddle forms the tiniest bit add filler rod and "flow" it to other half of part. In a corner joint you often will have to move torch between both weld pieces all the way around to keep puddle flowing where ya want it.
This is really the long way to tack and/or start a puddle - and works fine on steel.

Enough amps to puddle in 3 seconds or less works much better for me on aluminum.
I tend to be impatient, but it does work better when I teach others this way too.

You are battling aluminum's awesome ability to pull heat away from where you want it.
Avoiding letting the entire piece saturate with heat it the goal.

Dump it in there faster than it can get away and get after it :D

+2 with Oscar and Mosquito

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 7:38 pm
by GFab70
To welders who are experienced the puddle times are achieved much faster and most times are under 2 seconds. I am trying to give this fellow enough instruction to find a starting place. For me to sit down and wait that long for a puddle is ridiculous for a beginner it helps establish a starting point.

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Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 10:07 pm
by dirtmidget33
When ever anyone starts out on aluminum they want to baby it which as others stated is the wrong thing to do. Mash the peddle :shock: you will get a puddle then will have to wash it over to other part. Which ever part has the best ground is the piece the arc will jump to. After puddle formed you normally got to add a little filler to bridge the puddle to next piece. You will wind up with large tacks until you get used to it. Would prolly be best to practice aluminum fillet welds on two straight pieces to help you get the hang of it.

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 10:15 pm
by Oscar
GFab70 wrote:for a beginner it helps establish a starting point.
how exactly does it do that when it destroys an entire practice piece, or even worse, an actual project?

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 10:20 pm
by dirtmidget33
this might help you, one of Jody's videos

http://www.weldingtipsandtricks.com/tig ... m-tee.html

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 11:00 pm
by GFab70
Oscar wrote:
GFab70 wrote:for a beginner it helps establish a starting point.
how exactly does it do that when it destroys an entire practice piece, or even worse, an actual project?
That's my point Oscar, when you are learning it doesn't matter what happens to scrap pieces. Starting slow does in fact show beginners what to look for as the puddle starts. I agree with everyone about how experienced welders do it. I weld just fine on thin or thick and I myself "get on the pedal" right out of the gate. What I am referring to is how to learn what to look for as a puddle begins to form and stomping the pedal to the floor is not the way to learn. It allows no time for the cleaning action to do its job. Saying that, saturating a small piece of aluminum with heat and allowing it to drop out is not a good way to learn either. In my opionion starting slow and discovering what to look for is a better learning experience. I primarily weld 1 inch square tubing .062 wall and have no problems starting a puddle slow and allowing a bit of cleaning action to do its job before the heat absorbs into my parts and creates a puddle. ImageImage

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 11:07 pm
by MinnesotaDave
GFab70 - that's a nice jig you have set up in that last pic :)

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 11:10 pm
by Oscar
GFab70 wrote:
Oscar wrote:
GFab70 wrote:for a beginner it helps establish a starting point.
how exactly does it do that when it destroys an entire practice piece, or even worse, an actual project?
That's my point Oscar, when you are learning it doesn't matter what happens to scrap pieces. Starting slow does in fact show beginners what to look for as the puddle starts. I agree with everyone about how experienced welders do it. I weld just fine on thin or thick and I myself "get on the pedal" right out of the gate. What I am referring to is how to learn what to look for as a puddle begins to form and stomping the pedal to the floor is not the way to learn. It allows no time for the cleaning action to do its job. Saying that, saturating a small piece of aluminum with heat and allowing it to drop out is not a good way to learn either. In my opionion starting slow and discovering what to look for is a better learning experience. I primarily weld 1 inch square tubing .062 wall and have no problems starting a puddle slow and allowing a bit of cleaning action to do its job before the heat absorbs into my parts and creates a puddle.
Very well, point taken.

Now, if only newbies starting out on aluminum TIG only welded scrap at first, hehe. A lot just go right in and want to learn on the project, then can't figure out why edges burn/curl back into themselves and can't get them to join.

Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 11:11 pm
by GFab70
MinnesotaDave wrote:GFab70 - that's a nice jig you have set up in that last pic :)
Thanks Dave. It's simple and easy to change parts out quicklyImage I had 2 stacks like this on the last order.

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Re: Why can I never get a puddle on aluminum tubing?

Posted: Mon Dec 21, 2015 11:29 pm
by MinnesotaDave
That's a good pile of work there :)

Re: Why can I never get a puddle on aluminum tubing?

Posted: Tue Dec 22, 2015 12:07 am
by GFab70
After they learn what the puddle looks like, then it's on to get the pedal to the metal and let it puddle fast. Get some filler in and blend your 2 parts, at that point everything calms down and acts normal.

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Re: Why can I never get a puddle on aluminum tubing?

Posted: Tue Dec 22, 2015 5:24 am
by AndersK
Based on my own learning curve GFab70 give very good advices.

I didnt improve my results much until I did the opposite of what everyone said, slowed things down alot.

The difficulties with aluminum when new to it is to know when to add filler. To early and it wont fuse, just make a mess. To late and one be practising filling holes... Best way to learn is to work on scrap and take it slow. Watch the puddle to spot the "mirror" before adding filler and train on not letting the bead grow until it touches the tungsten.

Still learning every day .... :mrgreen:

Re: Why can I never get a puddle on aluminum tubing?be setup

Posted: Tue Dec 22, 2015 4:13 pm
by MosquitoMoto
My apologies for double post. I think my iPad might be ready for retirement.

Via throwing at a wall....


Kym