Weld aluminum with DC?

admin

My friend has a Snap On Flex TIG which I do not see a switch for AC, I think it is only DC as it only has a DC needle.  Anyway, I was at buddy's performance shop today and asked if you can weld aluminum on DC voltage and he said no you need alternating current... kind of made me sad.  Is he correct in that aluminum cannot be welding on a TIG machine in DC mode?
Reply:for DC TIG you need helium and the alum has to be CLEAN!!!!!ChuckASME Pressure Vessel welder
Reply:plus you need sharp red end tungeston and 5356 filler...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:Thanks guys - I knew it was possible.
Reply:Try using 75% Helium with 25% argon.  Wire brush (stainless brush) the faying edges immediately before weld and wipe with acetone or alcohol.  Just remember, once the puddles forms, weld like you mean it, as the aluminum heats, the puddle tends to spread if you dont keep your feed up.I r 2 a perfessional
Reply:DC GTAW for aluminum is still a Mil-Spec procedure.  Try it, let us know how much you hate it!CLEAN, CLEAN, CLEAN is the key.
Reply:i like it but you do have to go once you start no time to thinkChuckASME Pressure Vessel welder
Reply:I noticed that Mr. Zapster mentioned red (2% thoriated) tungsten on DC aluminum with helium. Is that because of the DC and helium? All of my Lincoln data says to use either pure tungsten or 2% zirconiated with AC and argon. Is thoriated better than pure tungsten on DC with helium when welding aluminum? I haven't yet done this but I would like to see how it works sometime. Thanks in advance.Last edited by gnm109; 07-10-2006 at 09:54 PM.
Reply:Originally Posted by gnm109I noticed that Mr. Zapster mentioned red (2% thoriated) tungsten on DC aluminum with helium. Is that because of the DC and helium? All of my Lincoln data says to use either pure tungsten or 2% zirconiated with AC and argon. Is thoriated better than pure tungsten on DC with helium when welding aluminum? I haven't yet done this but I would like to see how it works sometime. Thanks in advance.
Reply:OK, thanks. Got to save up for some helium to give it a try. LOL. The local purveyor of bottled gases where I go wants your first-born child and the deed to your house for welding gas these days. It seems that every time I turn around there's another price increase.......I'm not using that much but it's not cheap. Oh well....
Reply:DCRP/Argon can be done and the result as pretty as you get with AC. You are just limited in thickness.  Toss a 1/8 electrode on there and set current around 60-80A and run some beads on the 1/16-1/8 stock.
Reply:You don't need helium or 5356. I have welded 6061 "1/4 plate just fine with argon and 4043 on DC.
Reply:Originally Posted by PaulGYou don't need helium or 5356. I have welded 6061 "1/4 plate just fine with argon and 4043 on DC.