Gentlemen im having a Helluva Time...aluminum

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Hey gents  so here is the gest of everything. I havent welded alum in quite sometime. We have a nice Miller Syncrowave 250 circa 1997 . Has everything to do alum work AC, HF etc...Heres my problem. Was just trying to get some practice beads in finally had some decent material to practice on. The material is roughly 1/2 inch thick the filler is 3/32nd . I really need to know where to set the AC balance and AC intensity . I managed a couple of nice lines after about 20 horrible ones. Gas is 100% argon. 3/32nd tung 2% thor amps are between 100-125.I tried the ceriated but man did it suck . Burnt up wouldnt hold arc etc. . Should i be using max cleaning or max penetration. Honestly i have forgotten it all. One thing i did find was that im used to welding stainless so you keep the arc close but i got alot better results on alum when i wasnt nearly as close to the material and actually laid a few beads. I was about 1/2 inch away when i laid the decent beads ..... Any help would be greatly appreciated.....Have to say i didnt miss the noise of AC...lol
Reply:More amps.  Less arc gap too.My name's not Jim....
Reply:1/2" alum will make this a PITA. It's a giant heat sink and will pull the heat away pretty fast making it difficult to get a good puddle running. 100-125 amps is cold to do 1/8" alum and I'd find it next to impossible to probably run 1/2". Thats probably why you had to hold a 1/2" arc to get what looked like a decent bead. Usually we set the Syncy 250's at the school at 150 for the guys doing 1/8" alum. Usually set the balance at about 7 on that machine.Here's what we use for the night class. 1/8" alum cleaned with SS brush. 1/8" pure ( day instructor is old school) or 3/32" ceriated/lanthanated (what I run). Machine set at 150amps AC, set up to run the pedal, HF continuous, 7 on balance. They start ot runing single beads and then pads before moving to lap, T's, exterior corners and but joints in that order. Keep your arc close, 1/8" or so also..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:You need a lot more Amps & Helium for 1/2"  You should practice on something thinner, no point in spinning the power meter off of your house for practicing :-)Find some 1/8" to play with, it'll make it a lot easier to play around withClean the metal well enough to eat off of it.I run my AC Bal from 8-10, & use zirtung for Aluminum usually.Last edited by WeldingMachine; 12-23-2010 at 07:37 AM.Reason: same word twice..Buy American, or don't whine when you end up on the bread line.
Reply:Torn,You're going to continue to have a hard time "welding aluminum" until you learn the basics of tig welding.  From your comments, you're not even close.You may wish to go to Millerwelds.com and download a copy of their Tig Handbook.  An even better option would be to order their Student Pack ($25 incl shipping).  It includes a hard copy of the Tig Handbook as well as some other good information.For starters, with the Sync 250:1.  1/2 material (aluminum) using straight AC and argon, exceeds the machine capability.  Using an Argon/Helium mix increases the capability as does DC- and straight helium, but that's a whole nother subject.2.  Balance should be set between 7-8 (more penetration) for your work.  I don't have a clue what you're talking about with arc intensity, since the Syncrowave does not have the capability to vary the HZ (as the inverters do).3.  1/2" arc tells me you don't know what you're doing.4.  Thoriated tungsten IS NOT recommended for AC on a standard squarewave machine.  I prefer the 2% Lanthanated.  Some still use pure and let the tip ba11.  Some like the zirconated (haven't used it) as it will ba11, but takes heat better than pure.You don't just sit down at a machine, pick up a torch, and start welding aluminum.  You've got to understand the basics, which you haven't seemed to have done.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:Gentlemen thanks for all the replies its a huge help. Ive only been welding stainless steel for about 3 years and this was my first attempt at alum. I will try all the suggestions out and try to find some thinner material to paractice on . Thanks again...
Reply:1/2" electrode to workpiece distance seems excessive.  Holding such a large arc gap will make your machine put out more volts (and overall power) to make the arc span the longer gap.  However, excessive arc gap can cause a multitude of other "side effects": 1. it can flare the arc heat out excessively to the side, giving you poor control over the puddle's size and position.  2.  The width of the heat affected zone can be too wide, potentially exceed your shielding gas coverage.  3.  Uncontrolled "flared out" arc heat can melt the tip of your filler rod before you get a chance to dip it into the molten parent metal puddle.  (If you are dropping any melted blobs of aluminum filler metal falling on unmelted parent metal surfaces, expect that to be causing oxidation inclusions and poor welds.)If you find you are welding "flat out" with "the pedal to the floor" at full amps on that thick aluminum stock and even with a "max penetation" AC balance setting, are still struggling to get a good size puddle in your parent metals, some pre-heating of the workpiece can help this situation a great deal.  Even for the thickness of aluminum you are welding, I'd think a several second long blast from a propane powered "weed burner", (typically 300k+ BTUs) should do the trick.  (Your TIG machine, by comparison, is probably putting out no more than 15k BTUs of overall "arc power" at full tilt.)  High-BTU air-propane powered weed burners can be had for fairly cheap (<$50), and operate off commonly available BBQ-size propane tanks.  The push-button ignitor feature is useful for quick torch ignitions when occasional work "re-heating" in between weld beads may be necessary.  I'd recommend using it only in an area where there is nothing flammable for several feet in any direction.Edit - just noticed you are welding on the 1/2" aluminum stock just for practice.  If you are not planning on tackling a project made out of material this thick, you might want to just try and get some thinner, 1/8"-3/16" or so aluminum stock to practice on instead.  After you have your settings figured out by running some puddles on top of a piece and dipping the filler, try butt-welding some pieces together.  Last edited by jakeru; 12-23-2010 at 03:49 PM.