Tig aluminum DC

Looking to see what other people have to say about Tig welding aluminum DC only. Those of us without AC/DC Tig machines CAN Tig aluminum, instead of having to use the Mig spoolgun. I personally haven't tried it yet, I'm waiting on my Superultra 205 to arrive(while I wait for my Powerultra 205). But from what I have READ about it, it is very do-able, even with Argon instead of Helium, just have to clean the metal really well, due to losing the cleaning action of the AC. Everybody chime in, let's see who has done it, wants to try it, who says it won't work, etc.... Thin vs thick, settings blah, blah

Another option is to use both. The new Power TIG 255EXT has an advanced pulse that alternates between AC and DCEN for super deep penetration on thick aluminum with much less amperage required, yet still getting some cleaning action from AC. No matter how clean you get the material there will always be some oxide layer and with pure argon it just never comes out that good. You need the helium to really make it work. Of course you can go DCEP on thin stuff with a giant tungsten and get cathodic etching with pure argon. If you are a very experienced welder some of these things are possible, but there is a reason why most aluminum welding is done with AC.

Unless, like me, you only have a DC machine, then you have to work with what you have. also, just another option to try, maybe if you are just curious and like to try different methods, dont have helium, have a stick machine converted to TIg, etc.... Like I said - just want to open a discussion for those that like to / have to / think outside of the box.

If the reason you're DC welding aluminum is you don't have an A/C machine, it's probably going to be a misapplication of the process and won't work that well. The DC processes are not only effective for a limited (special purpose, rather) range of aluminum applications, but those also require other special purpose equipment (already mentioned; namely extremely large tungsten with water-cooling, or ultra high purity helium shielding gas), which doesn't make sense on a tight budget.

That said, if I were in your situation and had to DC TIG weld aluminum in a pinch, I wouldn't hesitate to grab some aluminum stick electrodes (they aren't that spendy) and experiment with DCEN TIG weld aluminum using them as flux-coated filler rods. Expect on having a flux-coated mess to clean afterwards, and good chance of getting some flux inclusions as well. Do your best to clean off all the flux afterwards. If you try this, let us know how it works for you.

I have done a lot of aluminum tig welding with DC- and pure helium. The process works very well. Very deep penetration. The bead typically will be shiny in the middle, sooty on the edges. It's a valuable procedure with thick aluminum. Nearly as fast as mig. It does require stringent precleaning since there is no cleaning cycle. What would require very high amperage with AC, could likely be welded with half that amperage with DC straight polarity. It also calls for a very short arc. Generally you simply lay the rod in the joint and move along that seam and fuse it together.

I personally have never tried alum. with DC but I know it can and has been done . I met a welder on a job site that used to work as a welder at disnyworld in Florida and he said they would dc tig aluminum all the time when he was there ( back in the 70's ). He told me how they would do it but that was 5 years ago and I do not remember what he told me. But I do remember that it did not sound like it was that hard to do. At the time I was a little skeptical of him possibly just pulling my chain but after working with him for a few months I believe it to be true. Today with all the advancements in tig machines most of the negative aspects of AC tig are a thing of the past. It used to be almost impossible to get a small bead tiging alum. but now you can dial in a machine to do what ever you need to do.

I played around with DC welding aluminum with flux and with out flux both with Argon.

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I remembered when I gas welded aluminum it worked well with flux so I tried it and it is easer, next test is with different lens in the helmet so I can see the weld better.
Then with Helium.