GTAW pipe welding? correct placement of weld? Help please.

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TIPS?Currently in school working on Tig welding 2" heavy wall. Forgive me I do not know the schedule. It is however, standard testing material -- if there is such a thing. I am comfortable running along the outside of the pipe, and have smooth patterns 6 to 12 while using 1/8th wire. I've now transitioned to learning to run a root, and filling it up.Running on a Lincoln machine - scratch startAmps - 1501/8th rod for root, and running all the way out.3/32nd gap5g1/8th tungstensize 8 cup - standard diamater aluminaNo landing on pipeI believe I'm running the root correctly.Essentially dragging torch along the wire and and rotating, thus melting it in?I can run a hot pass smoothly.After that------I am struggling to fill it up. Teacher said "run stringers" as the gap is going to be too wide to weave. One left side and one right side w/ a blend of the two in the middle.Mainly becuase of the diameter of the wire. Said max, three times the width in diameter of the wire.Also, I am continually getting the weldment onto the tip of the tungsten and it's fouling it up. Easy solution is raise the tip....But, point on metal - don't chase wire?Rough day -- Just venting little...Pipe welders and the like what say you?Last edited by jsm11; 06-23-2010 at 11:12 PM.1981 Lincoln SA 200Miller Trailblazer 302gMiller 211 Mig Welder w/ AutosetI'm learning to stick metal together
Reply:Your amps are too high for my liking, but if it works for you then I cant really say its wrong.  I run around 100-110 with the same fit-up your using.  However your wording is a it confusing, when you say your "dragging" the torch along the root I hope you mean to say your pushing it along and walking it forwards.  You should not be dragging it, in fact I dont even know how that would work. As for the fill passes, its really the same idea/motion as your hot pass you just have to pay more attention to your bead placement.  Maybe what your really having trouble with is walking the torch once you get out past the bevel?  This is what gives most people issues and the only thing that is going to help you out there is practice. Your last sentence is also lost on me, "....But, point on metal - don't chase wire?"  Im assuming your having problems with the wire melting back and balling up if you try and increase your arc length?  This makes sense with the amount of amps you are running.  Two things will help. either turn your amps down or bring your torch angle closer to perpendicular.Have we all gone mad?
Reply:150 does seem high, its doable but for that size I would hold it around 135 or let it cool between some passes. Are you only using a #8 cup and no others? You dont mention any other sizes. You need to experiment with cup size and tungsten stick out.UA Local 598
Reply:so you are "laying wire" as opposed to dipping and moving..id try the wide weave even tho teach says its too wide..if you already have the root and hotpass in how bad could you f it up? you might do the wide weave and thena narrower one up the middle...
Reply:Thankyou for the excellent responses guys,Yes, I'm probably running too hot, and need to let the piece cool in between. I'll make that adjustment.Yes, certainly need more practice on walking the cup inbetween the grooves. It's entirely different to me.Yes, I'm "laying the wire" as opposed to dipping and just trying to roll with it.Tungsten is out about 1/4"I walk the hot pass with #8 cup.Once the cup starts touching the physical weld, I switch to a #10.Run the cap with a #6 to have a nice tight pattern.I'm still a complete noob on it, and was just disappointed the other day. I thought it would be easier, as I'd been walking it around the outside of the pipe with no worries. Just got to keep the helmet down, brain engaged, and keep burning rod.Do you typically run stringer passes on 2" 5g? Seems like I'd be able to carry it just weaving.Earlier he had mentioned to run stringers on 2g and 6g as stipulated by the code. thanks1981 Lincoln SA 200Miller Trailblazer 302gMiller 211 Mig Welder w/ AutosetI'm learning to stick metal together
Reply:The reason you dont run a really wide bead is because when you move, you also lose gas coverage and contaminate your weld pool behind you. If you are welding heavy wall in 5g, then yes, stringer on the cap.I always use 4 cup on the root, 5 cup and 6 to fill, then maybe back to 5 when I am filling with stringers then a 6 or 7 to cap. Again, experiment with your stickout because some fill passes will be more difficult and akward, and a little adjustment may be all thats needed.Schedule 160 is most likely what you are working on.(you said heavy wall?) I weld this up every day so maybe I can offer you a place to start tinkering.Root at 95-98 (1/8 wire) stay on the wire and move quickly. You are not trying to wet the sides in at this point.2nd pass 110 (3/32 wire) now you are wetting the sides and still moving quickly, never stopping in the middle, side to side and the middle will take care of itself. In 6g, hold the high side just a little longer than the low side. Metal goes to the heat.3rd and fill,(1/8 wire) at this point I would go to 125 a couple passes and fill the rest at 135. At 135, you wont need to quench it or cool it and can weld pretty much non stop without it getting too hot to weld.Cap,  let it cool now, go have some lunch. (taco bell, not olive garden) Then turn welder down to around 125 and cap it.UA Local 598
Reply:Damn,Thanks a bunch...lol that's a great set of pointers....1981 Lincoln SA 200Miller Trailblazer 302gMiller 211 Mig Welder w/ AutosetI'm learning to stick metal together
Reply:the taco bell will give you additional gas flow....
Reply:Originally Posted by weldbeadthe taco bell will give you additional gas flow....