Tig machine question, Miller Dynasty 200DX

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New machine, pretty new to Tig, will this machine handle welding a 5/8" thick Aluminum truck frame rail?. Any advice on settings, as I am really not understanding this machine yet, Any input would really be appreciated.Thanks, John
Reply:In a word, NO!!No amount of preheat is going to make up for thickness/mass of the material you're talking about.Sounds more like a job for a spoolgun/push pull gun, backed up with a lot of amps.Sorry.  Great machine, just not for this job.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Ah, so sorry to hear that, but after a couple of verticles on a 1/4" tee joint, I had to questions my antics. I will do this one with a spool gun and continue the school of hard knocks, thanks for the quick reply.
Reply:Off the cuff, I'd say you may have a pretty good chance with the full 200 whatever amps, 100% helium, DCEN, 1/8" thoriated tungsten, 1/8" max arc gap.  If this is not enough arc heat input, try preheating.It's been 25 years ago, but I think I was using 300 amps full throttle, DCEN, 100% He, on 1" aluminum groove weld, with no preheat.
Reply:Pulser, thanks for the input, if I was to go to DCEN, would I be better of using my xmt350? Already rounded up Helium, as I picked this up earlier this morning her on the web when some one was asking about welding 1/2" thick Aluminum, of course I picked up a bottle of helium when I picked up the dynasty, every one in the weld supply thought I was nuts. Any more advice would be helpful. If if comes to the DCEN on the dynasty, I will need more input on how to even set the machine. Thanks again.
Reply:I think for DCEN, you'll just clean the aluminum, set the amps like steel, use the biggest tungsten you've got, and hit the pedal hard to start the arc with helium. You can't do wave shaping, etc. with the Dynasty on DC. It is just whatever it is set at from the factory. If, IF you could keep enough base heat in the piece to be welded, and could bevel both sides, and fill with multiple passes, bothinside and out, you could do it. But I would say a powerful mig would be better for a truck frame, as there is a lot of aluminum there to act as a heat sink against you.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Thanks ROJO, I will end up using a spool gun as this one needs to be done in the morning, I haven't enough time to dial it in on a practice frame rail, need not bugger up the one that still in the truck. I will have to tear it up when I have more time to learn this machine. I find tig work fairly easy with the xmt and dom tubing, Aluminum is another matter. Maybe I should of picked up a machine with less knobs to turn...Thanks again
Reply:Sorry, came back with this a little late, since you've decided to go MIG, but for what it's worth ...As I said, it's been awhile, but I think around 300 amps DCEN, with Helium, will be all the power you need for thick aluminum (like 1").  Put the pedal to the metal, and go.  Of course, you'll need a water cooled torch, and plenty of protection from the heat and intense UV light.  When I did this type of welding, the chiller was not up to the job, and the torch power cable blew out with a water leak, a couple of times.  The boss had me use black electrical tape to "fix" the leak, which was quite the challenge, then finally he bought a new power cable.DCEN with Helium takes a very positive and assertive wire feeding technique.  My technique is to strongly shove several inches of 1/8" wire into the pool on every "dip".  Same as the rythmic dipping of filler on steel, except pushing not dipping.Also, you don't have the "cleaning action" of AC welding, so pre-weld cleaning is very critical.  Degrease (solvent like acetone), then mechanically rmove oxide (clean file and/or SS brush).Also, a big gas lens should help, you have a big hot pool to inert.  The surface of the weld may be have some "scum" floating over it, and also black "soot" along the weld edges, this is probably fairly typical. Hope this gives you the visual image of how DCEN He works.Let's get back to "all the knobs" on the dynasty later.Last edited by pulser; 12-07-2007 at 12:03 AM.
Reply:Thanks again Pulser, When I get a chance I will have to play with this concept, I can see the next investment will be cooler and a torch.