pulsing vs. steady

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I recently got back into welding aluminum pipe for a company. I'm wondering if there's an advantage or disadvantage to pulsing with the foot pedal (not using the machine setting pulse) verses keeping a relatively steady amperage throughout the weld?Lincoln Square Wave 175 TIGLincoln 110v flux core welder (my 1st)Clarke 180EN MIG
Reply:Pulsing will allow you to manipulate the heat input in the base material being welded. With aluminum it is a VERY good heat sync so it dissipates heat very well as apposed to other materials. I would say it would be beneficial to keep the heat constant until the puddle starts to become more fluid as the material starts getting hot then start pulsing. It's been a LONG time since I have TIG'd anything so don't take what I say as the gospel.1973 Lincoln SA 200, Already replaced shunt coils, Idle board (SOLD)1984 Miller Dialarc 250HF, Miller water cooler, 250 AMP water cooled torch, you know the worx.
Reply:I do not start pulsing until I have at least one good bead and a good puddle. But I am having trouble with consistency in getting the beads to be uniform.  But I suppose that's from not doing it for a while as well as other problems described below.I am dipping the filler at the leading edge of the puddle and then letting off the puddle just enough to see the puddle turn into a "soft bead" then moving along to the leading edge of that bead to get back in to it. And repeating that cycle. I normally would not move so far, but I was told this is how they like to welds to look there.I also seem to be having trouble keeping the tungsten from destroying itself. I do not have the ability to adjust hertz/frequency. This is causing me problems as well because after a few passes the arc is all over the place. How can I fix thisproblem? I am welding on 1.9" o.d. aluminum tube with a wall thickness of about 3/16". I'm generally pulsing between 180-80 amps when doing this. I am using 1/8" red tungsten with a ball the same size as the tungsten.
Reply:Sounds like you have a transformer based tig welder(?).  With no frequency adjustment, you're only choice is to use as least cleaning action as you can to keep the heat out of the tungsten electrode (meaning the least possible EP/equivalently the most possible EN on the balance setting).  But to do this, you need to have surgical cleanliness at the joint because you will not be relying on the EP portion to do the cleaning for you.  Not enough EP and not enough manual cleaning will result in lots of black soot around the weld etch that should normally just be white, and lots of "pepper flakes" in the puddle/beads.  Not sure how 2%La reacts on transformer based machines, but on inverters it holds a sharp tip pretty well.  Might be worth a shot. 1st on WeldingWeb to have a scrolling sig! HTP Invertig 400HTP Invertig 221HTP ProPulse 300HTP ProPulse 200 x2HTP ProPulse 220MTSHTP Inverarc 200TLP HTP Microcut 875SC
Reply:Originally Posted by sen2twoI am welding on 1.9" o.d. aluminum tube with a wall thickness of about 3/16". I'm generally pulsing between 180-80 amps when doing this. I am using 1/8" red tungsten with a ball the same size as the tungsten.
Reply:Pulse....Learn to weld the right way.......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:180 amps on 3/16 would be too low for the way I prefer to weld. It would take way too long to get the puddle to form even on a small piece. I'd want to be up to at least 200, preferably closer to 220 or so. Pound the pedal and fly.I prefer to use Lathanated on alum. It still balls, but I can taper it and maintain a smaller ball, thus more control even if the machine isn't an inverter..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:Originally Posted by DSW180 amps on 3/16 would be too low for the way I prefer to weld. It would take way too long to get the puddle to form even on a small piece. I'd want to be up to at least 200, preferably closer to 220 or so. Pound the pedal and fly.
Reply:Originally Posted by zapsterPulse....Learn to weld the right way.......zap!
Reply:I think Zaps speaking of using the pulse mode on your machine, not pulsing the pedal. B_C manually pulses the pedal and says it gives him better aesthetic bead appearance.  He does some beautiful stuff.  It adds a whole notha level of difficulty to Tig when you are trying to be consistent. When I've tried it, the finished beads are flatter and kinda get an extra ripple to them.  It make some sense, at least to me, as you are adding more heat at the same time the filler is cooling the puddle.
Reply:I think part of the issue with "pulse" is how people use it. When you are looking at people like John Marcella, BC, Zap, Terry and a few others we aren't talking about people with minimal tig experience. We are talking about people who have the ability to fine tune their welds to end up with a desired end result. Pumping the pedal is just another tool in the box they pull out when or if it's needed.However the "average" guy usually isn't skilled enough to the point to accomplish things like this. Many times new guys are looking for a "short cut". They see guys pump the pedal of pulse and think that's all it takes to make nice welds. It's not. There's a lot more stuff going on that they really don't see. I'm not saying this is the case with the OP, just making a general observation from experience.I usually have a lot of students that get frustrated with me when I'm helping them learn alum tig. They make a giant mess and almost the 1st thing they say is the "machine is messed up" or that they need to change the settings. I step in the booth and make nice clean welds using the same settings. Only thing I tend to do is start off regrinding the tungsten to make sure I get rid of all the fouling. It's not the machine, it's the operator. I have learned to watch the puddle and know what the material is doing. My skill at heat control with the pedal is higher than theirs. I'll also readily admit my alum tig skills aren't anywhere close to Zaps, BC's or Terry's..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:If you need a pulse feature to get good welds on aluminum then you are letting the machine do your work for you....That's all well and good but let's say you suddenly get a new job and the machine you now need to run don't have it...What now?In reverse I could always just shut it off and go off on my merry way and you would not see any difference at all....Do I pulse my pedal now?I have no idea...I never watched my foot........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:Pumping the pedal for me is just using part of the current range I have available in the pedal, or finger current control. Like said in an earlier post, I pound that pedal at high amps. I melt into the root for penetration, then as I add the rod I back off the pedal some as to not blow out the bead and leave cold lap. The addition of a heavy amount of rod provides the throat thickness and chills the bead some too. Each bead is custom and sometimes I double or even triple dip depending on the throat or size I need. I have no choice sometimes so momentarily reduce my current. So I pump. The more you do it, the more automatic it becomes until it is machine like. Other times I do hold the current steady. It just depends on what the job is. I really don't even think about it, I just do it. There are so many variables. like gas mix, rod and base alloys, position, and application. If I have the range in my pedal, I pump, but only slightly mind you.Last edited by shovelon; 04-09-2014 at 11:19 AM.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 zapsterDo I pulse my pedal now?I have no idea...I never watched my foot........zap!