GTAW of Aluminum

[MinnesotaDave]

.......But it seemed counter intuitive because it was already so hot. I did manage to get a couple of beads decent enough to turn in for a grade, but there was 4 restarts from getting too hot and the weld face was around 3/32 wide with no distinct ripples. I mentioned all the different tungstens but results were similar with everything i tried.

My lap joint (flat and vert), using same set up, fared a lot better and I had a stack of dimes.......ish with pad plates in all positions. Is the tee joint really so different than the others, or is something not sinking in through this thick skull of mine.
oh also, i never felt like the puddle was established enough to walk the cup, so it was virtually all freehand.
this will be my first real post, besides intro, so if its not enough info or too much of something unnecessary then just let me know and thanks for everything so far.

Yes, the t-joint is different, takes a little more amps to get that puddle started.

Use enough amps to start a puddle and get moving in 3 seconds or less - stomp the pedal, do not "sneak up" on it.
Be bold, not timid.

If you take longer than 3 seconds to puddle, you will saturate the piece with extra heat and the weld will look like melted solder instead of a tig weld.

[Johnny Dixon]

Yes, the t-joint is different, takes a little more amps to get that puddle started.

Use enough amps to start a puddle and get moving in 3 seconds or less - stomp the pedal, do not "sneak up" on it.
Be bold, not timid.

If you take longer than 3 seconds to puddle, you will saturate the piece with extra heat and the weld will look like melted solder instead of a tig weld.

gotcha, will do, also gonna move up to the 3/32 lanthinated via southpaw. so that amp range of about 100 is right, just blast it and stay there til its right? do i need to oscillate it a hair while its in the joint or keep it stationary?

[MinnesotaDave]

gotcha, will do, also gonna move up to the 3/32 lanthinated via southpaw. so that amp range of about 100 is right, just blast it and stay there til its right? do i need to oscillate it a hair while its in the joint or keep it stationary?

That all depends on what you see, I generally hit enough amps that I don't have to move it - I just get a puddle.

I've also "speed tacked" outside corner joints on 1/16" aluminum at 230 amps for about 3/4 of a second.

So hitting it with high amps, then backing off as you weld, will become your norm.

You'll never know how much is too much on the initial blast until you try it.
When I taught my son I started with realatively high amp tacking so he would learn how to puddle quickly.

[Johnny Dixon]

That all depends on what you see, I generally hit enough amps that I don't have to move it - I just get a puddle.

I've also "speed tacked" outside corner joints on 1/16" aluminum at 230 amps for about 3/4 of a second.

So hitting it with high amps, then backing off as you weld, will become your norm.

You'll never know how much is too much on the initial blast until you try it.
When I taught my son I started with realatively high amp tacking so he would learn how to puddle quickly.

ya know, when im tacking it up, i do hit it hot, around 160 normally seems to work. that makes sense. working the pedal actually feels pretty intuitive too, so im not shy of having some amps on it. Ill definitely put all this into practice this weekend.
im on vacation for the holidays so im gonna just trying to get a LOT of seat time so that i will eventually start seeing the trees for the forest, lol.
There is a lot of information in my NCCER books, and theres a lot of videos on the net, but this is great guys, thank you, i dont care what the HVAC guys next door say, the welding community has some really good folks.

[Mikael]

You well done, Thanks for this great information.

[Willie B]

Aluminum, and copper move heat away from where it's needed at an alarming rate. To move along as fast as is reasonable uses less heat overall and minimizes the size of the heat affected zone. Don't give it time to conduct the heat away. As Dave said, start your puddle in a few seconds. I can't get the arc to land on both sides of the joint. I quickly heat each side till wet. Dab the filler, keep the arc there for a second to penetrate, then move down the joint, Good penetration is about keeping the arc close, near perpendicular to the joint, at the leading edge of the puddle. The "dime" look comes from the puddle freezing as soon as the arc moves away, and the melting of filler chills the puddle. The still wet portion of puddle is hidden inside the next "dime". The faster you move, the more distinct the "dimes" get. For smooth beads use lay wire technique, do not heat the filler with the arc.

[Johnny Dixon]

Thanks, it has improved somewhat, actually it started looming pretty decent. I've been backing off the heat and then stomping the puddle while dipping the filler, like manual pulsing I guess along with using the tips I've read here and other threads, Im still not ready for a welding test for a job I'm sure, however, I can see myself getting there soon. You know, willy b. I'm actually having more trouble with lay wire than free hand and that's on my list too. Probably because freehand is what I learned first. Also haven't tried swapping hands yet either (watch me be better laying it left handed, haha).
So the semester ended, btw, and my classes were GTAW [ hot and cold rolled steel 1/8" & 1/16" Vert and overhead] and Advanced GTAW [ 1/8" & 1/16" SS and Alum. Vert and overhead] grades were 94 and 80 , respectively. Thank you everyone for your help. GPA is 3.76. In pretty proud of this!

[Johnny Dixon]

Definitely not proud of the autocorrect on my phone. I promise I can spell better than this

[Willie B]

Once the necessary knowledge is in the brain, there is no replacement for practice. Padding beads will seem a waste of time, but it is the fastest way to get arc time. Welding joints between two pieces of metal is also good practice, more time is expended on prep, less on actual welding, and you consume more material at higher cost.

[gocirino]

http://www.maxal.com/files/QuickSite...g_6-11_doc.pdf

solid overview on welding Al using GTAW (and GMAW).

The Maxal Aluminum Guide has since been updated to include 4943.... http://www.maxal.com/files/QuickSite...g_9-12_doc.pdf

[atg]

Open corner on .125" sheet for my home brew tig cooler. Seemed to weld really easily though maybe it is actually a cold weld? Seems like most guys really use a lot of amperage and more filler per dab to get those fat stacked beads.

[atg]

Open corner on .125" sheet for my home brew tig cooler. Seemed to weld really easily though maybe it is actually a cold weld? Seems like most guys really use a lot of amperage and more filler per dab to get those fat stacked beads.

Kinda lumpy. Maybe should have used 3/32" rod instead of 1/8". Oh well.

Does tapatalk turn anyone else's photos upside down?

[WeldOnTopOfSlag]

Something to keep in mind is when you're wire brushing your aluminum to only brush it one way so as to avoid pushing the contaminants you just brushed away back into the part you're attempting to clean.
Also toluene is amazing for cleaning aluminum, though it's a carcinogen so be careful. Great thread and sorry if these were mentioned previously in the thread, I am pushed for time and didn't read the whole thing yet.

[Fab54]

Trying to learn aluminum TIG this thread is very helpful. I upped my tungsten to 3/32, upped my gas pressure, it made a huge difference. Just ordered some 1% zirconiated tungsten, 3/32 4043 filler, and a gas lens. I think I might get there eventually but boy is this tough. I think the most valuable tool for TIG is a steady hand. Sucks to get old.....

[Willie B]

Trying to learn aluminum TIG this thread is very helpful. I upped my tungsten to 3/32, upped my gas pressure, it made a huge difference. Just ordered some 1% zirconiated tungsten, 3/32 4043 filler, and a gas lens. I think I might get there eventually but boy is this tough. I think the most valuable tool for TIG is a steady hand. Sucks to get old.....

Lots of old guys here. I'd say my biggest handicap is vision. I use cheater lenses in the helmet, room lighting. The steady hand issue is a matter of finding something to prop on. I use copper bars, bar clamps, the table, or whatever I can. It gets better.

Try 4943 It's stronger, and wets really nice, you'll love it.

[GDSFab]

Normally if you have already removed the Oxide layer from the material, wiped everything down, and taken your time to make it really clean, you can float over 90% EN with no problems at all. Normally a rule that I follow myself is that i want just enough EP to get rid of that crud, but thats considering that your gas/tungsten/plate/joint is clean.

Another thing you could do before you puddle on it is to let the cleaning action cook out all the trash for like a second or two, then puddle and move along. Should help get rid of that trash soot you're dealing with. Hope that helped at all.

[Donald Branscom]

Argon is the correct shielding gas.
Helium added to the mix is used when the weldment is more that 1/4 inch thickness.
Helium is used for increased penetration.
Argon makes the arc stable and keeps away the oxygen.

[Alex77789]

Wow, thank you guys for the good information. I even don't need to ask you questions now, I've found a lot of answers. TNX!)

[HughF]

A link to the 'AC Tig howto' that was put together for our UK forum...

http://www.mig-welding.co.uk/forum/t...started.64695/

[Aaron@6061]

Hi nmaineron,
E4043 is a better choice (over 5356) since it isn't as prone to crack.

I disagree with this, at least in the application that have found it to be untrue. I've literally made 1000's of the parts below.

Before welding the thick flange on these parts (to the right of the arrows), I first form the sheet metal to conform to the round opening. Joints welded with 4043 rod were a noticeable amount more prone to cracking than ones welded with 5356 rod. This is when welding 5052 sheet.

[shovelon]

I disagree with this, at least in the application that have found it to be untrue. I've literally made 1000's of the parts below.

Before welding the thick flange on these parts (to the right of the arrows), I first form the sheet metal to conform to the round opening. Joints welded with 4043 rod were a noticeable amount more prone to cracking than ones welded with 5356 rod. This is when welding 5052 sheet.

You are right on this. 5356 is actually more ductile. It all comes down to technique. Most cracks are due to lack of throat. Packing the start thicker will prevent the crack from starting. I am actually doing a job that a previous welder had a crack centerline of the weld with 5356 and due to lack of throat.

[Aaron@6061]

100% agreed on the lack of throat comment. That seems to be a very common aluminum welding issue. Pack it in on the start, and on the stop and ramp off slowly.