Help me with TIG Aluminum penetration

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I'm a beginner with a Eastwood TIG 200. Trying butt welds on 1/8" aluminum. I can get a somewhat nice looking bead about 1/4" wide but it has little to no penetration (middle bead in the pics below). If I slow down alot and try for penetration, I end up with a really wide (1/2" or more) and flat, somewhat undercut weld. The bottom bead sunk in a lot and cracked. This is using the foot pedal set at 140amps, 3/32" electrode and rod, and about 15CFH. I tried dialing in max penetration on the AC balance and it helps a tiny bit but not much.What am I doing wrong?
Reply:For full pen. welds on aluminum get the puddle started fast with alot of amps then back off a little untill the puddle is the size you want. Then add a little filler and watch it sink into the metal a little and move forward a little and add more. It can be hard to get just the right amps/ travel speed to get reinforcement on the root and face of the weld. It takes some practice.
Reply:Also you should try some 1/16 aluminum, its allot easier to get full pen Attached Images
Reply:My guess is you are doing all the typical new guy alum tig mistakes. Amps are a bit on the low side. I'd push it up to at least 150 if not higher to start the puddle fast. I'll often set the amps even higher, say to 180-200 to get things going really fast. My guess is you are going too slow and are over heating the material from what I see. It seems counter intuitive, but more amps allows you to use less total  heat on alum. Alum is a wonderful heat sink and is pulling the heat out of the puddle faster than you are putting it in. when that happens, as soon as you get a puddle going, almost the whole area around it is hot enough to melt as well, hence the wide beads.It wouldn't also surprise me if you did those joints back to back without letting the material cool. Too much residual heat will just make things worse.Bead number 2 looks on the cold side as well, which is another typical new mistake where they correct by trying to go colder rather than hotter.I know some people will tell you to start off with alum. Honestly with all the students I've helped teach tig, I've found very few who could start off with alum and manage to do a decent job. The learning curve is just too steep with alum. Steel is a much easier and more forgiving material to work with. Top that off with the fact you are trying to do but joints, which are probably the hardest of all the joints to do. With alum, when things start to get out of control, almost always the answer is to go faster, often with more heat, not less, so you can outrun the heat that is building up in the material. This is extremely hard to do if you don't have the basics of heat control down very well. You need to be able to react instinctively and correct before the problem gets out of control. With steel, you can back off the heat, slow down and regain control. That just makes things worse with alum.Last edited by DSW; 10-26-2012 at 10:54 PM..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:Wow! Another FNG that picked up the basics of alum tig welding rather easily . You hit the nail on the head when you said that getting full pen is harder than partial penetration butt welds.I would not change too much, but get more coupons and keep going. At some point the solutions will become apparent when you get comfortable with the process. They say you don't get good until some 10,000 hours.After a while write down the best settings you came up with for alum and switch over to steel. Dial it in and run a bunch of steel plates. Then switch back over to alum and you will be amazed at how much better you got. It is a good idea to try out both AC and DC. As mentioned above, I instruct AC and alum only, but then I am not a teacher. Some are more comfortable teaching DC. I believe it is easier to teach alum on inverter tigs, and alum is the main goal of my victims. Of course the hard part is the setup, which you have already mastered.Good job and practice hard. Work that Eastwood.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Originally Posted by smokinwelderI start aluminum slow to allow the arc to clean the material some. Then increase than back off as I start going. You do have some decent welds here and there. Keep practicing. It will come. Or stop on by....I'll have ya welding in a hour with slick welds...
Reply:Thanks for all the tips. I'm outta gas so it's off to the welding supply for more and then to the scrappy for some small scraps I can turn into bigger scraps.
Reply:When your traveling with the torch, dip move forward, then move back into the puddle then forward dip and repeat. Hard to explain, but should look something like this.< etc. hope you understand what I mean. Jody has a good video of what I'm trying to explain ill try and find it
Reply:There ya goYouTube:
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Reply:Originally Posted by astaindsoul5446There ya goYouTube:

Reply:When the aluminum hits the table the first thing I do is crank the amps ALL the way. Its like the three cants of flying: you cant use the fuel in the hanger, you cant use the sky above you, and you cant use the runway behind you.If I have many (10) or more of the same item to weld Ill re-adjust the machine to allow a most comfortable foot position on the peddle.
Reply:Originally Posted by shovelonThat is exactly right. Jody does a good job on his videos.
Reply:Another tip is to make sure the edges, and even some of the back side are clean. Also good to have a backing plate to trap the argon and therefore keep some of the back side shielded.
Reply:WD,That's a typical Aluminum weld.   The beginning had penetration because you sat on it, then the end did because the entire piece got hot and you swirled on the end to prevent a crater.  That's the way 90% of my aluminum welds looked when I started out.The middle weld was the first one I bet.  The other two are too hot without enough filler. I'm far from great, but I think DSW is right on in his assessment.  The more you practice, the more it will come to you.  To get good penetration on aluminum, you gotta dip filler when the pieces are about to or just keyhole.  When things start to heat up, you have to move faster and not just come off the pedal.  You need to do a bit of both.  Hard to explain but you will get it in time.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum