Aluminium welding on DC inverter

admin

Gday all, from what ive read all roads lead to welding aluminium on AC, as I only have a 170Amp DC Inverter, i was wondering if it as all possible to weld aluminium with it. I know its most likely highly unreccomended.Its just to weld some 19mm tube as bow rails on my brothers boat.
Reply:This should tell you all you want to know and morehttp://weldingweb.com/vbb/showthread.php?t=43291
Reply:Why is helium used instead of argon?  Is it just for the additional heat?  But then that additional heat makes it exceptionally difficult to control for thinner aluminum?  If so, why not just use the Argon in the first place?I am curious about this as I have basically free helium.  My father runs a balloon / helium distribution / catering company.  We frequently get partial tanks back from customers when their leases run out or their event is over and they did not use as much as they expected...Please excuse my TOTAL noob-ness as to Tig welding, as I have never even touched one let along used one extensively...  Until I stumbled on to this thread and the ones linked to from it, I thought AC was a requirement for Tig welding as one direction of current flow would heat the metal, and the other would clean/ blast the oxidation off of the aluminum.. Without that cleaning action, how is it possible?
Reply:This thread has a good deal more information than the one previously recommended.http://weldingweb.com/vbb/showthread.php...light=AluminumThis is the result of a search for Al TIG threads.http://weldingweb.com/search.php?searchid=1488769
Reply:thanks for that first link ! Very interesting.
Reply:I've read in one publication that Helium is required to obtain the high arc temperatures necessary to liquify the aluminum oxides, in TIG DCEN mode.  Apparenly argon gas can't get hot enough to melt the aluminum oxides, and you'll have the "big molten puddle under oxide skin" effect.I hope to play around with some Helium someday, so I can verify whether it is true or not.   But I know like probably most others here that TIG DCEN with 100% Argon has oxide skin issues.For oxy acetylene aluminum welding, you can use flux to dissolve the aluminum oxides, and the thought may cross ones mind to try that flux with TIG DCEN to dissolve the aluminum oxides.  However, I would envision that stuff burning up and leaving spatter on your TIG cup, tungsten, and collet body (I've never tried it though, so I don't know for sure...)Alternately, you might have some success trying to weld thin aluminum with a really big tungsten in DCEP mode.  If you try this, get as large diameter tungsten as can fit into your TIG torch.  Those with AC TIG setups with adjustable balance can tell the effect of increasing DCEP % (the "cleaning" side of the balance knob).  It is sometimes helpful to reducing penetration, and spreading the arc out wide.  It works great for build-up operations, actually.  It does really heat up the tungsten though.What is the thickness of your 3/4" aluminum tubing you want to weld; .065"?Last edited by jakeru; 09-13-2010 at 02:59 PM.
Reply:I have used flux on AC GTAW aluminum. The flux was used just as you stated to help with heavy oxide layer.  Also just to prove it will work I have a procedure for GTAW argon 5cfh/7018 on A36 outside in 10mph winds got good charrpies(sp)  too...  the argon was used only tho keep the arc stable and to keep the tungsten oxide free.
Reply:Wow... very eye opening Fat Bast!  Thanks for the info.  I think I will need to experiment with TIG + flux sometime.I'm thinking you must have not had your tungsten stuck out very far if you were avoiding oxidizing the tungsten with a 10mph wind though?
Reply:2can86You can stick weld aluminum with your DC  inverter.
Reply:You need 99.999% pure helium for it to work good. Also for  thin aluminum it does not work very well. The helium that is used to fill gallons will be too dirty.
Reply:DC TIG and thin wall, small diameter aluminum tube are not going to mix well at all.  I'm also guessing you're probly not all that experienced at welding small diameter, thin wall tubes, out of position, in an on-site environment, or welding aluminum in general, or you wouldn't be asking these questions.  On top of that, this is a job where the welds should look good in order for it to be considered a success, in my opinion anyways.   The results of you doing this project with DC TIG should be 'entertaining', so please post pics so we can all laugh at the melted pile of mess.Bottom line, if you want this project to come off acceptably, have an experienced aluminum tig pipe welder (with an AC TIG machine) do the job for you.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:actually, now that I think about it.. I just remembered they mix around 10% O2 into balloon helium to keep kids/idiots safe when they inhale helium to make their voice funny..
Reply:I have tested DC TIG with argon and flux. I used normal TIG rod and separate flux, normally used for gas welding aluminum. That let me use minimal flux for better visibility and easier cleanup. If you don't have access to one of the preferred processes, it seems like a useful tool in the toolbox. Here's my page with photos and discussion.http://hildstrom.com/projects/dctiga...lux/index.htmlI have also tested DC SMAW. Here's my page about that.http://hildstrom.com/projects/stickaluminum/index.htmlYouTube, Website
Reply:I have done it on accident before not knowing my machine was still on DC. I was wonder what the heck was going on it welded a little funky. I had 100% aragon. Then I tried it again another time on purpose on DC but it didn't seem to want to start a puddle and it was just kinda burning the aluminum. But it can be done with aragon. I know u can do it with helium and get great penetration. Try it and post a pic