Trouble welding .032" aluminum with TIG

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Hello! I'm having a helluva time welding outside corner joints with .032" aluminum sheet.  I'm using a Syncrowave 250 DX with 1/16" Thoriated tungsten grounded to a fine point.  The problem is that when I go to strike the arc, I can see the arc dancing all over the place and the aluminum I'm trying to weld just disappears into a glob of molten metal.  I've tried messing with the gas flow, grinding a step into the tungsten, and heating the metal with a torch before I start welding.  No matter what I do, the arc remains crazy unstable.  Every once in a while I'll get a nice concentrated arc and I'll be able to make a nice weld but the next twenty beads I do afterward are terrible. I can lay down some strong, nice looking beads on flat pieces but when I butt two pieces together, either in a flat configuration or a corner joint, the arc decides it doesn't want to behave anymore and tells me to go pound sand. What gives?Last edited by killabeez; 02-05-2011 at 03:00 AM.Reason: Spelling fail
Reply:first thing that comes to mind is ground , make sure both pieces are grounded good , use more clamps or "third hands".and then depending on your welding machine/settings  your start current can be higher then weld current thus making the holeif nothing works, start the weld on the welding rod.--------------------------------------------------------------www.becmotors.nlyup, I quit welding.. joined welder anonymous
Reply:You might try a copper heat sink on the inside corner.
Reply:Hello killabeez, I believe Boilermaker374 has your answer, although I generally use a piece of stainless steel plate or angle depending upon the joint configuration. Another thing of equal importance is to be sure to carefully clean the weld joint before trying to weld it. A dedicated SS brush is a good thing, using a wipe down of acetone followed by Isopropol alchol is a nice additional touch. Just be sure to keep either of these chemicals away from where you are doing the welding due to being a fire hazard and allow a bit of evaporation/drying time. Since you are using a Syncrowave 250 DX I believe you also have an arc balance control on your machine, where is that set at? With the tungsten size that you mentioned using you may wish to set it slightly towards the penetration side of the balance. Good luck and let us know if you have had any better results. Best regards, Allanaevald
Reply:killa,Think the biggest problem we have here is a total lack of experience in tig welding.Looking at your other posts, I suspect you're going to need a LOT more hood time before you're comfortable with thin aluminum.  .032" material is NOT where you want to start.With that said, there are a few things you may want to check.On the Sync 250 set your AC balance between 7-8.Set the HF to continuous.Get rid of the thoriated tungsten for aluminum.  It will tend to form a series of small ba11s around the tip and drop tungsten into the bead.  Pure tungsten was the old standby with a balled tip.  I personally have gotten away from using it.  Better options available.  I use the 2% Lanthanated for aluminum and sharpen to a crayon tip.  If a balled tungsten works better for you, then you may want to try the zirconated.  Handles heat better than the pure, but still forms a ba11 on the tip.Get yourself some 1/8" thick coupons and use them to get a feel for "heat control" with the pedal.  Don't even worry about adding filler til you get the heat down pat.You've got a lot of "learning" to do before you tackle .032" material.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:Your story sounds much like mine the first time I tried welding aluminum.  For me it was trying to save an already dead radiator.  I didn't work, had to buy a new one anyway.FYI, 1.5% lanthanated is normally easier to find than 2%  Some welding shops round it up and call it 2%.  You can also do it with .040. tungsten.  The arc will start easier (maybe less current).  I think that Syncrowave has the ability to turn down the initial starting amps (check the manual).  That might help as well.With a clean, dedicated wire brush, make sure you removed the oxides.  If you don't, by the time you burn through the top layer, the insides will already be molten.Backing plate helps.   Copper is the best for this, but I've used stainless as well.Your gonna need filler.  I've never again tried to weld aluminum that thin, but I would think aluminum spool for MIG might be a good, available, choice for filler.  Like a spool of .035.  Don't try fusion welding of aluminum.  6061 will crack when fusion welded. (guess how I know  )Last but not least, make sure you have a decent ground.   If you are just laying it on the steel welding table, I think you might find that its actually arcing to the table.  again, scrape a little of the oxides off and clamp there.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:your arc is unstable because you are using the wrong tungsten, get a 1/16 PURE tungsten!  pure tungsten is the only way to go on aluminum everything else just dances.  this is much more noticeable on thinner material.  i do not understand why people use thoriated on alum....BUT to each their own.what kind of amperage are you set up with?  low low low low heat, if the material is disappearing before you get going, you have too much heat OR you have a bad torch angle.  i also wouldn't suggest more "penetration" (especially if you don't do this very often), if it was me i would keep it more towards the "clean" side.  keep the heat out of the material.  if you can't get it to cooperate, use a steel or copper plate on the other side of the joint.hope you have some thin fill rod for that material, 1/16 might be too big!
Reply:Originally Posted by ryanyour arc is unstable because you are using the wrong tungsten, get a 1/16 PURE tungsten!  pure tungsten is the only way to go on aluminum everything else just dances.  this is much more noticeable on thinner material.  i do not understand why people use thoriated on alum....BUT to each their own.
Reply:Thanks, everyone for your responses.Here's what's happening with my welds.  As soon as I strike the arc, everything immediately in the vicinity of the tungsten disappears because the arc goes crazy.  I've noticed that if I depress the pedal down farther at the start, the arc stabilizes but the thin metal can't take the amperage.  The work is grounded well and I've got a block of aluminum to keep the joint square.  Boiler, I'll try the heatsink next.Allen, my balance is at around 6-7.
Reply:Here is what I have noticed with my 250 DX (without the pulser) on the thin stuff. If you try and start right at the joint its like the machine gives you the full amps for a split second, blowing the edges all to hell. what I do without using a heat sink is angle my torch off the joint aways like about a 1/4", press the pedal to get that first arc, and stabilize the arc as you bring it into the joint. FWIW I use the 100% green tip tungsten all the time on aluminum. One of our last "supervisors" had heard at some point that green was all to use on alum so he ordered me 2 packs of each 1/16 3/32 and 1/8  thanks I guess.
Reply:Never mind my first post, have you tried to turn down the amps? I can see you didn't bother to clean the joint , and probably the arc "goes crazy " cause the tungsten is too far from the work.--------------------------------------------------------------www.becmotors.nlyup, I quit welding.. joined welder anonymous
Reply:Originally Posted by killabeezBoiler, I'll try the heatsink next.Allen, my balance is at around 6-7.
Reply:Originally Posted by larpheadFWIW I use the 100% green tip tungsten all the time on aluminum. One of our last "supervisors" had heard at some point that green was all to use on alum so he ordered me 2 packs of each 1/16 3/32 and 1/8  thanks I guess.
Reply:Oh BTW, I actually checked the manual (at least on latest 250DX with integral cooler).  Seems you can also adjust the starting characteristics:Select 1 (light/soft start) − when welding atlow amperages on thin gauge material.Select 2 (medium/normal start) − factorydefault setting used for most welding applications.Select 3 (high/hot start) − when welding athigh amperages on thick(http://www.millerwelds.com/om/o363ag_mil.pdf)I suspect your 250 has similar settings.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Lesson learned?----- killabeez needs to thoroughly read the machine manual, then purchase and study Miller's intro. pack; along with other items they offer at no cost.That basic stuff really can help one avoid hassles as well as solve them--faster thanany message board where the rest of us are simply guessing at what is and is notthe machine setup, operator technique or lack thereof, etc.Blackbird
Reply:Originally Posted by con_fuse9Lanthanated and Ceriated have higher melting points than pure.  That means for a given setting, you might be able to use smaller diameter - which in turn will give you better starts.  I notice that Miller doesn't even list green for their square wave machines anymore....  See the bottom:http://www.millerwelds.com/resources...ints_tips.html
Reply:Not to Hijack this thread. But I DID manage to scrounge up one piece of 3/32 Ceriated (orange band) today. Must have came with the machine or something. I used it ground to a point and checked the machine for the soft/medium/hard start function (after tracking down my manual)....turns out mine was set on medium. Set it to soft and tested on a couple of coupons before I started repairing lids and panels on our 3kw generators.WOW  like a whole new machine. I AM Loving it!! Man I love this place.Thanks con_fuse9. Ill buy you a beer
Reply:Originally Posted by killabeezHello! I'm having a helluva time welding outside corner joints with .032" aluminum sheet.  I'm using a Syncrowave 250 DX with 1/16" Thoriated tungsten grounded to a fine point.  The problem is that when I go to strike the arc, I can see the arc dancing all over the place and the aluminum I'm trying to weld just disappears into a glob of molten metal.  I've tried messing with the gas flow, grinding a step into the tungsten, and heating the metal with a torch before I start welding.  No matter what I do, the arc remains crazy unstable.  Every once in a while I'll get a nice concentrated arc and I'll be able to make a nice weld but the next twenty beads I do afterward are terrible. I can lay down some strong, nice looking beads on flat pieces but when I butt two pieces together, either in a flat configuration or a corner joint, the arc decides it doesn't want to behave anymore and tells me to go pound sand. What gives?
Reply:There is nothing wrong with using 2% thoriated, but you DO have to ball it. grind it like you normally do and set the machine to DCEP to around 30 amps and strike a arc on a piece of scrap (can even be a piece of steel it doesn't matter) for a split second until you see the tungsten ball up, then switch back to AC and strike a arc on the same scrap for a second and it will be ready to weld with. If you try and weld with the 2% thor like normal it wall start making multiple split balls that will make you arc dance around.But I really don't think that is your problem from looking at your pics, looks like the material is not clean enough (I don't see any brush marks or any indication of cleaning) and the oxide layer is keeping you from doing a clean weld, you can see the black contamination. You need to go out and buy a few SS small brushes and only use them for this project. Aluminum may look bright and shiny but untill you take that brush to it and see all the oxides coming off its not clean. And you have to do both sides. And then wipe with acetone with a CLEAN rag, and clean your filler with the rag too.Good luck and post pics when you try again.
Reply:i use 2%  thoriated and have for 20 yrs for all my SS and Alumi i don't ball it  just grind to a crayon point and weld, it will make a small ball on its ownidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441