aluminum... consistant problem...

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hey guys...been welding some aluminum and i am having a problem....  i can weld the plate or tube very easily... but when i try to do a peice that i cut and clean... it just spatters. (see below)i am using a stainless brush that is dedicated to aluminum to clean the surface and the joint prior to welding and an acetone wipe after that.  you can see that i am welding fine up to the joint... and at the joint all hell breaks loose.suggestions?100% argon, 1/16" tungsten on AC (tried 2% and pure... same result) with 1/16" 5356 and 4043 rod... all the same result.  AC balance is set to auto on my precision 185 with no pulse.MattLast edited by shlammed; 04-27-2011 at 11:25 AM.
Reply:Looks like you might be getting O2 contamination from the back side of the joint.  How tight is you fit up?BobI'm spending my Kids inheritance, I dont like him that much anyway!!!!!!Enuff tools to do the job, enough sense to use em.Anybody got a spare set of kidneys?  Trade?
Reply:what are you cutting it with?
Reply:cutting with a bandsaw.Fitup is quite tight.  Rbeckett.... does this infer that i should be purging the pipe to rid this problem?
Reply:What is it that you are trying to weld?   It looks like the aluminum tube melts ok until you get to the thing on the end.  It looks like an aluminum tube with a galvanized steel band clamp on the end.  galvanized steel, or what ever it is, would explain you problem.
Reply:I think it's just a rolled bead. Almost looks like an IC tube
Reply:From the photo it almost looks like there is something inside of whatever you're welding on. If so, what is it, what is it made of, and is it, and the inside of the piece being welded as clean as the outside?
Reply:its the exact same peice of tube, just where i made a cut.  its an aluminum tube with nothing inside of it.
Reply:are you using any type of cutting fluid? it can get trapped in the rough face of the cut and no amount of wire brush and acetone will get it out.
Reply:What is your gas flow set at?Too much will do that at joints.....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:From what I see is that ring is a slip fit onto the tube because I can see clean tube under the ring where it was burned away......I would say you have a crap piece of casting for the ring......Try chiseling the ring off and see what you have under it....I bet its a separate piece from the tube......That would be my guess because it wouldn't weld good and just all of a sudden screw up like that if it was the same piece....And 1/16  is a bit small for that application, I would use at least 3/32.......and maybe 130 ampsLast edited by B_C; 04-27-2011 at 05:49 PM.  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:improper purge air flow or getting air contamination from the gap where you cut it. Seal off the tube and change your flow rate and I bet it takes care of your problem. Thats my guess anyways.
Reply:You typically don't need to back purge aluminum.......  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:I am of the opinion there is a clear coat of some kind inside the tube. When you light up painted/ coated aluminum, it goes to poo almost instantly. Anodizing is also a possible issue, but it is rare to see a pipe anodized only on the inside. The fact that you have no issue on the outside of the tube tells me that there is a story behind the inside of the tube............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:I'm still looking for the part where you're "welding fine" up to that point.If you think those beads are "fine", then we have different standards.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:Originally Posted by SundownIIII'm still looking for the part where you're "welding fine" up to that point.If you think those beads are "fine", then we have different standards.
Reply:Originally Posted by B_CYou typically don't need to back purge aluminum.......
Reply:posted this on Honda-tech as well.some of the suggestions there as well as here led me to being able to weld the two peices.main thing was playing with the AC balance a little...fitup is fair, but not good in the above picture.   the above was just to show the issue.The bandsaw had been using cutting fluid so i cleaned the saw up and there is no residue on the wheels anymore.SundownIII, thanks for the support.  your input is appreciated.  the purpose of the welds on the tube were just to show that it would accept the filler and that the joint wouldnt.  since this i filled a 3 foot peice of this tube full of beads upon beads to work on my welding (before i ran out of tube)I have only been TIG'ing for ~2 months now.
Reply:Originally Posted by OverRaTeDAgreed. Not really what I meant even though thats how i wrote it, lol. I was referring to the lack of fit up due to the wide cut in the pipe combined with incorrect argon flow.....that prob further combined with a cleanliness issue. But I'll admit I'm not an aluminum welding expert -- just giving my guess.
Reply:Originally Posted by shlammedthanks, since this i have acetone cleaned my tubing on the inside as well.
Reply:does your filler ball up in a gummy mucus that you keep  feeding into the weld ??? i'd say too much amps + incorrect feeding technik , can you change the balance a bit more to dcep? and also feed fast in&out.--------------------------------------------------------------www.becmotors.nlyup, I quit welding.. joined welder anonymous
Reply:Originally Posted by SundownIIII'm still looking for the part where you're "welding fine" up to that point.If you think those beads are "fine", then we have different standards.
Reply:Wagin,No.  I don't have a "solution" for the original question.Photos are not clear enough to determine what the real problem is.  At first glance, it would appear that the band is of a different material than the tube, but the OP stated that was not the case.What was "very clear" though, even though the OP stated his tubing beads were fine, that he was not using enough heat (beads just piled on top of the tube), and that his consistency (dip and travel) left a lot to be desired.Then you get the "experts" recommending purging the tube????For the life of me I can't understand why so many new tiggers immediately want to start on tig welding aluminum tubing, before they've even developed basic tig skills.Not one other poster had even commented on the lack of heat, consistency of bead, or the craters the OP left at the end of each bead.  If new tiggers would learn to walk before they try to run a sprint race, they'd be better served in the long run.The OP stated, "I'm welding fine up to that point".  I'm saying that there was nothing "fine" about his beads up to the point everything went to he11.Now, if you think everyone should get a trophy for turning on his tig machine, then that's a whole different story.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:Correct me if I'm wrong, but it looks like you took some tubing and cut slits in it and tried to weld up the slits.In that case, your pretty safe on the material.Any contamination on that saw blade?What kind of blade?  How old is that cut?  It looks like you were trying to weld aluminum like you might weld steel.  Aluminum doesn't flow, when you heat it up, at some point it will just curl back.  I would suggest you put down two tack welds first, one were you are going to start the bead and one where you are going to end it.  Build the stack of dimes off a tack weld.  When you finish on the 2nd tack weld finish hot and make sure you melt it in.  You can try bridging the two sides but it typically will be 'cold' (not tied in well, sitting up high etc.)You basically have two choices.  1) tack weld first and build your beads off the tack. or 2) build a 'bridge' accross the gap and stack dimes from there.  When you build the bridge you will get a keyhole that you will melt and fill on the next dip.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Is kind of interesting how the problem is getting discussed and ideas worked over.Sure looks like crud was ground into the slit by the bandsaw blade. Or perhaps crud pressed into the crease during beading.Whatever clean the hell out of it and keep trying. Sometimes things just happen and you have to persevere.Good Luck.That looks like IC piping.  I usually do mine with about 100-110 amps with 3/32" tungsten ground to a point gas flow at 18.  I bet your bandsaw blade is causing the problem or oil from the bead roller.  Try cutting the tubing with a sawzall and don't just cut a slit.  Cut the whole way through sand the edges clean and bevel them a little.  Good fitment and cleanliness is critical on IC piping.  I know it's frustrating to take all the time to prep and clean on a practice piece, but you need to use good prep if you want good results.Chuck Norris was born in a log cabin that he built with his own bare hands.
Reply:Wow you guys are still talking about this............  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Thanks for the tips everyone.Sundown.  I went through a beginner welding course where i did personally just focus on TIG.   At that point i was doing mild steel all the way through and i managed to get quite good at it. The main reason i am trying to do this aluminum pipe is because I need to have ti done for my car project so i can drive it.Since this i have cleaned my bandsaw blade and even after i touch up the lips with a 2" 3m disc on an air grinder to rid contam.fitup:Tack (as mentioned earlier)Weld:Granted im not the smoothest of welders yet... but i am working on welding pipe in the 5g (horizontal fixed) position.im just trying to get welding time under the hood too... so im building things like this to do what a peice of flat bar would have been fine for...
Reply:looks better, but you will have better results if you chamfer the ends of the pipe on a belt sander before you weld them together.   You are making progress, but you definitely need some work on your consistancy.  I'm guilty of that too, so don't take it as in insult.Chuck Norris was born in a log cabin that he built with his own bare hands.
Reply:Too cold, rev that thing up and slow down.....  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:And stop slamming the pedal off, you are leaving craters.Try to project when you will be stopping and gradually taper off the pedal while stirring the puddle in a tiny circular motion until the arc extinguishes.Keep it up, you are catching on.
Reply:Good call on the dirty blade. What i'm going to say is contrary to popular belief but i dont care. Flame suit on.. I use an aggressive wood blade with a lot of wax to cut. it flies through the material. I never clean aluminum unless its very old and dirty or its expanded metal (usually has a light mist of oil). All that wire brushing IMHO doesn't really help much unless you like your work all scratched up. I hate foot pedals. I just have a cheap on/off switch taped to the torch. Don't get me wrong I know the pedal has its place but not for aluminum and definitely not for someone just learning. And if i feel its necessary i just put a little down slope on it and i can pulse it just like a foot pedal.  If i was welding that pipe i would just cut and weld. why ruin that nice polish. And i hate it when people rant and don't ever back it up with anything . so here.www.performancealuminumfabrication.com
Reply:So, travisc454...I've got to ask. What is the purpose of that observation deck on the truck? Nice work! I don't recall ever seeing anything like that up here in the North. I'm thinking maybe an auctioneer's platform? Maybe judging platform for a rodeo? A parade truck for some VIP? I'm sure I'm way off but please tell...Your aluminum welding practices certainly go against the grain of conventional thought (according to most of the info I've seen). However, they are right in line with similar advice I received from an instructor at the college I attend. He only took second in the national Skills USA competition a year or so ago. I've seen the guy TIG aluminum and its like a work of art.Eric
Reply:Yeah if your just running flat straight beads there is no reason to have a pedal.....Now on projects where you have to go  through an inside corner that pedal comes in pretty handy. Or when your on a round part and the temp of the piece is getting hot you need to let up a bit on your power that pedal comes in handy also......  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Thanks for the advice yet again guys.I do know about letting off of the pedal, but i generally forget when im in there as i am focusing on the torch angle around the tube.  also, i have had a few instances where pedalling back was needed like at the end of a peice of sheet and this tube since it heats up SO fast being ~0.065" wall 6061.I will get some more practice in this weekend (my shop is ~1h away) and i will report back.
Reply:Also, for this last picture of the tube, i am using a 1/16 2% th tungsten with a large diameter gas lense that i usually use for my stainless welds.i have tried pure and 2% on aluminum is there any other suggested tuingsten to use that might give a more steady arc or something benefitial over what i am doing now?
Reply:Im guessing deer hunting with dogs and CB radio's. Ive seen setups like that in North Carolina where its legal.