TIG Welding Aluminum with DC

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I know I know I know.  I was always taught AC only for TIG welding Aluminum because the alternating current breaks up the oxidation layer.HOWEVER, I heard there is a certification for DC Aluminum TIG.How is this done?  I was thinking a super high Pulse could maybe break that oxidation up like an AC current could.How is this done?
Reply:Search on DCEN aluminum welding. There are several threads. You should use helium, and it makes for good, instant penetration, but it is harder to do than AC tig.
Reply:ive done it before, its not real pretty, but if you do it right and wire brush it after it will look like a wire brushed ac weld... only with twice the penertration. pretty much just set it to dc- i kept the tungesten sharp and just run with it. the first dip wont really look like a puddle it will look like the metal is just melting, then once you dip it will bring the bead up to height.
Reply:I have read a lot about it. But before going into that . . . I tried it.  At my skill level it is basically impossible.  The metal just grays and almost sort of ashes -- no matter what I tied I could never get it clean enough before trying a start.  Trying to heat the metal just made it seem to oxidize in front of me.Now . . . what I've read.  The metal must be clean (as in clean -- no oxide, no dust, no hydrocarbons, no nothing -- you get the idea -- perfectly clean as usual but cleaner and then clean it again; clean the filler wire, clean the shop, . . . .  ).  Gas -- pure helium.  Starting -- don't wait for the shine of a puddle -- it won't happen.  When it looks like it might be melted, go for it.Good luck.
Reply:Done lots of it...It sucks.. ...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by zapsterDone lots of it...It sucks.. ...zap!
Reply:Did a bunch light pole bases years ago.  Tube was about 8" diameter and 1/4" thick, base was 3/4" thick.  DCEN with Helium, 1/8" 2% thoriated tungsten, 300 amps, 1/8" filler.  Works great for heavy aluminum, no preheat needed.  Requires large diameter filler wire shoved into the weld pool rather forcefully.