Experimenting with Al AC tig

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I dont have any experience in welding, just recently got into it. I am running an older Miller Econotig, 25cfm Ar, 3/32" ceriated, #7 cup. I may have a total of an hour or two of torch time on mild steel. Today I switched my machine to ac, got some scrap Al and ran some beads. I am getting a very wandering arc:Is there something I am missing ? I wire brushed the base material, wiped it with acetone prior to running my beads. I know I need to work on my heat input, but I don't think wandering arc is normal.Thanks in advance for any feedback.
Reply:What amps are you running?You need at least 250 on the initial hit and that may straighten out the problem......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Your CFH is too high. Should be 15 to 18.Last edited by shovelon; 08-16-2014 at 04:03 PM.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:Thanks for your quick responses. I can put 150A down if I floor it. I will try flooring the pedal to establish an arc and back it off to keep it going. I will also turn down the Ar to about 17 cfh.I will let you know how it goes.Thanks
Reply:how thick is your scrap aluminum?I am not familiar with that machine, can you adjust the ac balance on it? When you say it is older I will assume it is a 60hz transformer based machine who's frequence i sstuck at 60 hz?If you can't adjust the ac balance and you run it for a minute or two at the default of 50%  EN 50% EP , than your tungsten will start to ball/bead up and you will get a wandering, arc, that's just the nature of the beast.  a 2% lantinhated blue tungsten holds it shape very well, that is what I use.In conclusion I believe with your set up wandering arc will be "normal" as soon as the tungsten balls up. Keepign the torch near the metal and moving as fast as you can may help, but since you are new, those aren't really going to happen till you get a lot of practice. IMHO.
Reply:It's a 60Hz transformer machine and I ran my beads on the backside of tread plate about 1/8" thin. Since I can't adjust AC balance, do you suggest I sharpen the tungsten just as I would do for steel ?
Reply:tread plate must be grounded well, all those bumps on the back dont' help any and a poor ground contributes to arc wanderabsolutely groudn the point sharp. there are numerous wrong advise on the web and youtube about balling up a tungsten for aluminum. it is nonsense, even old transformer machines will keep the tungsten sharp for a few minutes before it balls up a bit, really depends on your amps and wheather yoru torch is air or water cooled and type of tungsten. do not use pure tungsten/green, when I started, I read green was good, it is the absolute worst and balls up in seconds.
Reply:I ran more beads and the results are much better now. Thank you all for your feedback and advice !!! Here is what I did different this time:- 17cfh Ar flow- tungsten sharpened to a point, as soon as it began to ball up, out it went to the grinder- More current to initiate arc
Reply:Originally Posted by 1DucI can put 150A down if I floor it. I will try flooring the pedal to establish an arc and back it off to keep it going.
Reply:I never understood why welding books and websites recommend using a balled tungsten for aluminum but yet when welding steel they recommend using a poignant tungsten If appointed tungsten is good for steel why would it also not be good for aluminum?A bald tungsten spreads out the heat and that's truly not a good thing with aluminum that's why I don't recommends them
Reply:Careful with that thoriated tungsten Duane!!! It's radioactive ya know. You might start glowing or something! But you'll be able to weld in the dark without a flashlight (might be a good trade off!) LOL.. LOL..Real welders know how to penetrate!(Equipment)Whatever can be used to beat my opponent into submission!
Reply:Originally Posted by AluminumWelderI never understood why welding books and websites recommend using a balled tungsten for aluminum but yet when welding steel they recommend using a poignant tungsten If appointed tungsten is good for steel why would it also not be good for aluminum?A bald tungsten spreads out the heat and that's truly not a good thing with aluminum that's why I don't recommends them
Reply:Nice chart Dave. I've never seen the heat transfer in photos like that. Sure dose make it easy to explain!Real welders know how to penetrate!(Equipment)Whatever can be used to beat my opponent into submission!
Reply:I stand corrected what does the .125 and the .5 mm indicate in those charts...?
Reply:Thanks for posting up the chart and info Dave. MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Originally Posted by AluminumWelderI stand corrected what does the .125 and the .5 mm indicate in those charts...?
Reply:Superawesome charts Dave !!! Understanding theory and physics behind any process makes learning the actual process much easier. Duane, I sharpen my tungsten parallel to the stone. My stone got a bit groovy already, but its not too bad yet, I guess I will dress it to get it flat again. I also wipe the tungsten with acetone before installing it in the torch. Looking at the charts Dave posted, my tungstens look resemble the 35 degree image with a sharp point. Should I go with the 15 degree and dull point ? I need to work on my pedal control, I tend to run things too hot, my scrap piece of aluminum has many holes after today's session. Since my machine is an older Econotig, I don't have the ability to set the current limit available at pedal, it's always 0 to 150A so I need to watch it.Last edited by 1Duc; 08-16-2014 at 11:23 PM.
Reply:At 150 amps, I run about 45 degree taper, small flat on the tip, let it ball as I weld.If the ball gets larger than the tungsten diameter I re grind, or increase the size of the tungsten if it happens too quickly.My machine is not an inverter, I don't have adjustments for balance or frequency either.Use enough amps to puddle and start moving in 3 seconds or less - otherwise you are just saturating the piece with heat.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Originally Posted by duaneb55Thanks for posting up the chart and info Dave.
Reply:I noticed that as soon as my tungsten looses its sharp point, my arc begins to wander. Keeping this observation in mind and looking at the charts above I think I can get increased arc stability and control with a sharper tungsten angle. I need to find more Al and I will put this theory to test tomorrow.
Reply:More amps straightens out the arc wander - too little amps for the tungsten diameter and the arc will wander all over the place good luck and keep after it Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:You'll learn what works best for you but my blunt points are typically ground at a 45 or a little more with a flat spot of +/- 1/64".  Time to experiment as your thread title states and see for yourself what does what.Keep in mind pure tungsten is supposed to ball up so don't even bother sharpening that at all.  If it balls more than 1-1/2 times the tungsten diameter in a short period of time, you're either running too hot or the tungsten is too small for the required amperage.As for your peddle control - watch the puddle.  Once you punch it to get one established, the puddle will tell you if you have enough amperage or not as you dip the filler.  If it's on the ragged edge of being too cold the puddle will freeze (stick your filler rod) as you dip the filler.  Tapping the peddle a little just as you dip the filler can help keep the puddle stable.  To help keep the filler from overheating and melting off the end in a glob with a peddle jab/dip, pulling the arc toward the back of the puddle while dipping works but requires three actions (jab peddle, move torch and dip) all at once and takes practice.  There are obviously basics but overall techniques vary as much as there are weldors (persons) so keep experimenting and see what works best for you with your machine.  You'll likely find you'll use a variety of techniques based on what you're doing.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Dave and Duane, thanks for your advice !! I really appreciate and value it.
Reply:No need to redress wheel it will just groove againGet a $10 harborfreight diamond wheel and put it on your grinder side sharpens tungstens much better
Reply:Originally Posted by MinnesotaDaveI don't own the publication the pic came from, but judging by the increased penetration in the .5mm examples, I think it is referring to the diameter of the flat spot ground in the tip.  In general, a larger flat spot increases the penetration.it also explains why the 180 degree example only has the one photo, can't put a flat tip on it as it's already flat.Back in the day before all these newer tungsten mixes (and inverter machines) came out all I ever used for AC aluminum welding was 2% Thoriated tungsten (mostly 1/8 and 5/32 diameters).   I would grind a blunt point on it and then "ball" it by switching the machine to DCRP and strike an arc on a small copper plate slowly bringing the amperage up until it melted the size ball I was looking for.  And the size ball I was looking for was based on what amperage I was going to be running to weld with.   If you put to big of a ball on for the current you were going to be welding at you'd get to much of that arc wander.   To small a ball and you risked blowing off the end of the tungsten while welding or getting what's known as a "Thorium Spike" forming which would cause the arc to not go where you were wanting it to.
Reply:Originally Posted by 1DucMy stone got a bit groovy already, but its not too bad yet, I guess I will dress it to get it flat again.
Reply:just because in theory a 180 tip gives better penetration, and those pictures look great, it's not going to be what anyone uses. Because in reality your arc will wander too much and you spend so much time trying to get a stable arc, you will in fact probably add more heat than if you had used a pointed arc to begin with. we weld mostly thin aluminum .093 and thinner and our experience has been with a balled tip you spend a few extra seconds which causes the thin wall to blow through, so theory is nice, but not practical in the real world for thin metals. I've not welded much thick metals so can't say if the theory holds up better in those circumstances.
Reply:Originally Posted by AluminumWelderjust because in theory a 180 tip gives better penetration, and those pictures look great, it's not going to be what anyone uses. Because in reality your arc will wander too much and you spend so much time trying to get a stable arc, you will in fact probably add more heat than if you had used a pointed arc to begin with. we weld mostly thin aluminum .093 and thinner and our experience has been with a balled tip you spend a few extra seconds which causes the thin wall to blow through, so theory is nice, but not practical in the real world for thin metals. I've not welded much thick metals so can't say if the theory holds up better in those circumstances.
Reply:I'll have to try a balled tip again.when I was learning to tig aluminum a sharp tip helped. this person is in the same position and found the same thing true, i think that is why beginners find the recommendation to ball up the tungsten so hard to swallow because it makes welding harder for a beginner.
Reply:Originally Posted by AluminumWelderI'll have to try a balled tip again.when I was learning to tig aluminum a sharp tip helped. this person is in the same position and found the same thing true, i think that is why beginners find the recommendation to ball up the tungsten so hard to swallow because it makes welding harder for a beginner.
Reply:Lots of good info here. Looks like you got your arc wandering figured out. Along the tungsten topic though, I will let my tungsten ball naturally and redress to blunt point as needed. The thing I find with blunt or slightly balled tip is that it seems to take more current going back and forth in AC mode without spitting or breaking off.  The end of a sharp point will usually overheat at the higher amps needed for Aluminum. If there is a problem with tungsten failure I would probably go to the next larger size. When I first start on cold aluminum, I sometimes weld with my balance set to put more heat to the work to get it warmed up, then adjust for better cleaning.Last edited by bobhdus; 08-18-2014 at 09:01 PM.
Reply:Great Thread!  I got a lot of condensed info from this - should be a "Sticky".Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:I finally had some time to get back to my experimentation tonight. I got some 3/16" material to practice on and I found that although a sharp pointed tungsten is a good way to learn arc control on Al, especially on thin material, I've learned to appreciate a ball tipped tungsten. Since I was practicing on 3/16" material, the ball allowed me to deliver more heat to base material, something that a sharp point couldn't do especially as soon as I step on my pedal I had the point turn into a ball. I went back to some thin stuff I had lying around with the ball tipped tungsten and I can control the arc as well as I did with the sharp pointed tungsten last time I tried it. I also learned that I need to give the pedal a nice push to get a nice arc going and overcome arc wander. I can easily blow a hole in the thin material when I floor the pedal on startup, but I was able to find that sweet spot that instead of wandering arc flaking stuff off all over I can almost immediately go to stable arc and once I get it going I back the pedal off a bit to run the bead without melting holes in base material. To sum things up, tonight was a good learning experience, everything posted in this thread came into play.Thank you very much for pointing me in the right direction.
Reply:Hey good news - keep after it and have fun Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:I had issues with arc wander and wide arc with a 60 HZ machine. I had best results with smaller tungsten, and a blunter grind. Higher frequency overrunning will help stabilize the arc. This is accomplished with adjustment of spark gaps.
Reply:Originally Posted by MinnesotaDaveI welded two pop cans together with a balled tip. I also tried it with a pointed tip, about the same results.Don't get me wrong, low amp DC welding I use a long taper, don't need the penetration.The more amps I need to use, the more blunt I grind the tungsten.Theory and facts often complement each other when talking welding.
Reply:Much better today. Still have to work on my torch control. I notice I can do short runs pretty consistent, but longer runs are tough, I find myself 'out of position' passed the half point.