pipe welding ,,,,want your advise

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im welding on 5inch xx putting a root in w/tig,,,,,,5/32 opening,,,,,,,,im feeding the bottom by feeding through the bevel...now i know every machine runs different so i set my machine hot enough so that the 1/8 filler wire melts like butter when in the leading edge...i think its a damn good bead,,,,but it is just a little tiny tiny bit above flush,,i would really like it if it was a little more convex,,,,now my machine is set on 125 amps.....i tried with a lower amperage but the filler kinda sticks a little more than i like,,,my gas flow is on about 23,,,,,,now after i finish the bottom of the pipe i like to switch over to 3/32 filler for the rest of the pipe......at the same amperage the 3/32 filler puts a smoother root in than with the 1/8th filler,,,,,,im happy with the root doing this but i worry about going from job to job using 10,000 different machines,,,and those inspector's can be some huge *** holes too,,,,,so im tring to get as good as possible so i never have to worry about ******* inspector's and advise would be great as im off to the next pipe job in about 2-6days,,,,,,,,,thanks  and one more thing i'm not running my tungston way up on the bevel to get suck back,,,,im just barely tieing into each side of the bevel....and in not taking my sweet time either,,,so why would the 3/32 filler be producing a more convex root than the 1/8th filler?Last edited by wareagle; 02-03-2013 at 10:20 AM.
Reply:i work in a coal fired power plant so i deal quite alot with tig roots. For myself i always use 3/32 filler no matter the joint size. I use generally a strong 1/8" to light 5/32" gap, and i know most dont, but i run my file over the bevel to pit a very very subtle land on. On the bottom i feed inside the bevel slightly until i am at about 7:00 and then i start filling from the outside of the bevel. I freehand so i incorperate small weave edge to edge, now on the top edge of the bevel when i weave up thats where i add my filler, when i am weaving across my tungsten is pointed down into the bevel to allow the arc force to push the root in, when i reach the top edge of the bevel i slightly point my tungsten at the the filler material and i add, its not a dip, i literally push 1/2 to 3/4's of an inch of the rod into each dip, and then weave back down and quickly back up and repeat. I get a strong 1/8" buildup on the inside i could have more if i wished. But on a 2" sch 160 test wether it be 2 -1/4 chrome, stainless, inconel, i cut a 3/32" tig rod in half and i usually have maybe 2" of rod left by the top.
Reply:same thing i just went out in the garage and tigged the root in sch 160......125 amps with 1/8 filler,,,,carbon s,,,,the bottom was good,,,im sure it will pass but the 3/32 filler looks way better,,,,,,,,,anyone know why this is,,,,,,,,,5/32 root opening same amps same gas flow same tungston,,,,,,at 125 amps the 3/32 filler looks way better,,,,that running hot too where the filler kinda melts and goes in like butter,,,,not hardly and sticking,,,,i like it hot so the stickin and cold wire/**** are keep out,,,,,,,,,,but why does 3/32 look much better????
Reply:thank you,,,,,,i do the very same thing,,,,this is weird,,,,i put a very small landing on also,,,,,,the keyhole will not get crasy and i like to run hot so the filler dont get coldwire,,,,,,thanks for the info....everyone else is a big fan of 1/8 filler,,,,,,,,,i like 3/32 better,,,,,,slower and u push alot more in but hey,,,,,if just feels right to me,,,,
Reply:my opinion, a 3/32 will look smoother because it's not as big a heat sink as a 1/8. I usually use a 3 when I do socket welds because I can push more wire in and fill up the undercut that tends to form on the top leg.On a butt weld, you can get more penetration on the root bottom if you look at the backside thru the bevel from up top. You won't be able to see the outside of your puddle and it takes some practice to keep from sticking your tungsten, but you can better control how much buildup you get inside. I'm still trying to get the same result by doing it the conventional way, it has something to do with the angle the puddle comes off the end of the wire, if you keep your wire more perpendicular to the puddle on the inside of the pipe you get more buildup.It's kind of hard to explain without a picture, but you want a greater angle between the tungsten and the wire.
Reply:I have all the respect in the world for you pipe welders who can stick the filler rod through the pipe. I've tried it, nothing short of a disaster! I don't think I've stuck the tungsten so many times in my life.  Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:it takes some practice.that's a cool picture!
Reply:I just don't think I see well enough at my age. I've tried different power reading glasses, but the distance changes coming around the pipe. Welding on the outside, no problem I can keep my head the same distance all the time. I should try it again, I hate being defeated on things. I thought it was a cool picture too. Hard to explain to people about sticking the filler rod through the pipe, but this pictures tells it all. I don't remember where I found that picture.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:were not allowed to test this way unfortunately to replicate a "boiler insitu type weldment" if your welding a water wall, chances are your not feeding from the inside, its our companys procedure but i would recommend using 90amps 3/32" tungsten, ive found 90 amps to be more than adequate on pipe as 2-3" thick wall thickness, when we get into the really heavy headers/steam drum repairs were preheating the snot out of it anyway and holding it at temp so 90 amps seems to work well. You can go slower and concentrate on staying "INSIDE" the bevel, thats maybe your issue? the only time i walk up past the root opening is if i need some time to close up the key hole a touch. this could help you push more material into your root on the inside. Less time on the bevel and more time in the root gap will provide more reinforcement. although i would assume you would be correct at 125amps with a 1/8" filler, i personally havent rooted with a 1/8"
Reply:i just tried it with 125 amps with 3/32 wire and shoved a good bit in,,,,it probably too much amps but the root looked pretty damn good!!! i figured out 1 thing,,,,im a 3/32 root man!!!