5G or 6G Tig root problems

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Does anyone have suggestions on how to keep filler while putting in root on 5g or 6g tig pipe from balling up and fouling the tungsten.  I am welding on carbon  6" sch. 40/80 with knife edge land, 1/8 gap,1/8 filler wire, 2% 1/8 tungsten (thoriated), have tried between 85 and 100 amps.  Especially between 6:00 and 9:00 after starting to put in some wire it will start sucking down to the tungsten, ball, and then foul it up.  I've tried going a little faster, I've tried 5/32 gap and 1/8 wire using loose wire.  Loose wire works great for 2G.  Maybe not enough patience yet.  This is last week in pipe welding at tech school just trying to perfect some things and this is a problem area sometimes.
Reply:Go to 3/32 tungsten, it will give you a more concentrated arc and still easily carry enough amps for what your doing.  1/8" is overkill and might be putting to broad of an arc/to much heat into the pipe.Have we all gone mad?
Reply:Watch your torch angle.  Too shallow an angle, pointing the tungsten at the filler, will cause the filler metal rod end to rapidly overheat and ball up.  Keep that arc length short as this will focus the heat on the puddle, and not spread it around to other stuff nearby; like the end of your filler metal rod.  x2 on the 3/32" tungsten; and keep it sharp.  A dull, contaminated tungsten will disperse heat over a much wider area.  This can cause all sorts of problems, including the one you're describing.I was taught to lay the filler in the joint and keep it tangent to the pipe.  Then weave the arc/torch over the filler rod, consuming it as you weld the joint.  You need a little less heat when using this technique, say 70 or 80 amps.  I like it because I don't have to move the hand holding the filler.  I just have to keep from letting it slip into the tungsten.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Thanks for the reply sn0border and A_Dab.  I will definetely switch to the 3/32 tungsten and work on sharp tungsten,  and lay wiring filler.  Does that technique give some reinforcement inside?    My instructor has worked in nuke plants and paper mills and said some require some reinforcement.  He is a stickler for this.
Reply:You might find that once you switch to a smaller tungsten you will get more reinforcement because you will be putting in less heat and less of a change for suckback.Can you run a 3/32 gap with 1/8 filller?  That will help as well and makes it easy to just lay the rod in the joint.Have we all gone mad?
Reply:I gotta say that 3/32 or 1/8 tungsten is good for what you are doing, go about 100 to 110 amps. Your heat will be what ever you set your welder at, not your tungsten. Suck back happens when your puddle cools too quickly, and that can happen no matter what size tungsten you use.
Reply:A bigger tungsten creates a broader arc which overall puts more heat into the material than a smaller, more concentrated arc.Sure, you can do it with 1/8" but with the problem he is having it sounds like going to a smaller size will help with that.Have we all gone mad?
Reply:sno:   That makes sense.  I've tried reducing amps.  With the broader arc that isn't allowing it to cool enough to stay in place as you are moving along is it?  Also will try 3/32 gap , 1/8 wire. w hughes:  Part of the problem since I am in school and haven't been Tig-ing that long is just learning to manipulate torch and rod and at the same time staying steady.  I am going to try 3/32 tungsten.thanksLast edited by war eagle 81; 04-24-2009 at 11:59 AM.
Reply:shorter arc length is needed end of story. whether that is fixed by smaller tungsten or closer stand off is your choice. i have done those joints with those perimeters with good results if you need to use 1/8 tungsten it can be done/
Reply:quasi:  I will try that on Monday. Thanks
Reply:A Dab , Quasi, snoborder,w.hughes,Tigged  some carbon pipe today in 6g pos. sch 40, knife edge land, 85 amps, 1/8 gap, 1/8 wire, 3/32 tungsten, 1/8 tungsten stickout.  Sorry no pics but when I finished there was a big difference.  The more controlled arc worked better not melting off alot of wire or more than I could handle.  Having just started Tig pipe in January 09 I am very pleased.  The end result was pretty close to a wedding band with between 1/16-3/32 reinforcement very consistant all the way around.   thanks for all the help.war eagle