Worse than Fido

[JohnT]

I bought some more scrap aluminum for practice purposes. It is 1/16 inch.
Thinking that outside corner joints wouldn't be too hard i decided to try to make a small tote box.
Well... Edges melted, filler globbed, arc was popping, and things never got any better.
I didnt have this much trouble the very first time i tigged.
Im using 1/16 E3 tungsten, 1/16 filler, #5 cup, 8 lpm argon and 60 amps. (Tried several amp settings from 35 up to 65)
Is this stuff too thin to be practicing on? Contaminated argon? Or just need more practice
Its too ugly even to show pictures.

[Rambozo]

Pictures would help diagnose the possible cause. I would say start with a bead on 1/8" plate as your first practice pieces. Be sure everything is spotlessly clean. Sand or stainless wire brush then wipe with acetone. Also be sure you know what your "scrap" material is. There are some aluminum alloys that are not weldable. Some weld fine, but then crack, while others are not pure enough to weld at all.

[JohnT]

I did the bead on plate thing and even did some joints with thicker stuff, so i thought I'd "graduate" myself.
Granted, i do not know what this stuff is, I bought a 12"x48" piece for $5 at the local recycling place. Cleaned and acetoned just like my previous practice pieces.
I already destroyed this attempt but i will take pics of the next.
Thanks for the quick reply Rambozo

[Blaster]

Have you tried bead-on-plate on this stuff?

Does your machine "pulse"?

Outside corners on thin material is one of the hardest things to weld in Aluminum, maybe try a couple of butt welds too...

[JohnT]

Thats a good idea Blaster. I didnt do bead on plate with this stuff but I will tomorrow. Some butt welds too.
My machine is a PP164 with pulse options of either 1 or 25 pps.
Here is a question.... Does the 1 amp per thousanth apply to corner welds?

[Rambozo]

Lots of things can change how many amps you will need. I always advise using a pedal whenever possible. That way you can make adjustments while you are looking at the puddle. Especially with aluminum, you will need more power when you start out, but as the heat builds in the parts, you will back off quite a bit. So for something like a 1/16" outside corner, with no backing, you might start with 75 amps to get the puddle going, but be down to half that by the time you finish the weld. One thing that will help is to have a backing piece to help sink some heat and support the weld metal.

[Blaster]

You should definitely experiment with your pulse. It makes a Huge difference for things like what you're doing. It's hard to imagine but even at the highest setting (25pps?) it does a LOT!

Those "rules" aren't hard & fast for very much, not sure about your situation, 60A might be cold but I realize you're fighting burn-through though. Do you have a pedal? I don't worry so much about setting my Amps/Thousands because I'm peddling it anyway.

Depending on those pulse settings you can count on setting the Main Amps higher than you would without pulse though (realize that 50% background and 50% time-on means that main setting is being "diluted" some)