Tig pipe welding questions

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Hello guys, ill try to make this short, this is my first semester (5 weeks) of pipe welding, and i have a few questions.I had a company come to my school ( jv industries) and they were checking on us, they had us do a 6g test and a 6gr test 2" sch 180 carbon steel, they liked what i can do and offered me a spot in there company and school, till late april i want to learn how to backfeed to get a head start on there school and my teachers have no clue how to do it.I hoping you guys can help me out some on how to back feed, i currently practicing 2g position 6" schedule 40 carbon steel, i have my gap about 5/32 with a 1/32 landing and i'm using 1/8 filler metal er-70, using pure argon, 1/8 tungsten 2%, clean out metal. Any tips will be appreciated, i will listen, and i will do my best. I can post pictures on my progress if requested.If i left out anything please let me know, i'm new.Thanks for reading and have a good day.Last edited by Rios; 03-19-2014 at 12:23 PM.Reason: just cause
Reply:Bump bump
Reply:Originally Posted by RiosBump bump
Reply:Thank you buddy for the comment and I agree with it being unnessary But that company that came by wants you to weld that way for some reason, I already had a gap close on me, its sucks haha. Thanks again,Last edited by Rios; 03-19-2014 at 05:29 PM.
Reply:showdog, if you were to back feed, how exactly would you do it, i tried smaller wire yesterday and its great! i had a good root, just have to practice on making it consistent all the way around the pipe, instead of 5/32 i tried a 3/16 gap and a 3/32 filler wire. I have to learn how to tig all the way out, do you change cups as you get to the final cap, because i find it tough to walk the cup b/c its catching bevel every time, what do you do? I was looking at post about backfeeding and i notice a lot of comments from you, sounds like you know what your talking about. Great stainless tube work!, saw the pics, thats another thing i have to learn too.thanks again.
Reply:I've been working on a stainless produced water treatment facility and we only backfeed unless the gap  slams up on us. I find that a 3/16" gap is best from sch. 10 10" to sch 80 12". I run a 5/32 wire where its wide and a 1/8 when it gets tighter. 3/32 is useful but you have to push so much wire in to get a nice convex root. Biggest thing with back feeding is to make sure you are consuming all the wire. you will frequently have cold wire bits sticking out, for me it happened more with stainless than with carbon. You also want to push in just a little rod which will make sure you are consuming your wire. I like to feed a few inches from where my torch is, you do not need to feed from all the way across the pipe unless you absolutely have to. Hardest part is getting your hands to feed the filler while running your root.
Reply:Very useful information buddy, thanks very much for that, I been trying a 3/16 gap with a 32 landing and I used 3/32 wire, im going to try 1/8 wire. When you say you don't need to constantly keep feeding wire, what your saying is I can just keep the wire on the leading edge of the puddle?
Reply:You need to feed a bit of wire but not as much when you use bigger rods. It takes a lot of 3/32 filler to make a nice convex bead with a 3/16 space, whereas a 5/32 basically just needs to melt. A 1/8 is just a happy medium for me and you just need to feed a little. My rod typically goes through the bevels about 3-4" above my torch and I hold the tip of the filler in the puddle but inside the pipe about 1/8" maybe a little less or more on occasion. When your too hot you can feed a little extra and you'll see your land disappear and a hey hole will develop. Turn down or back up to let it cool but don't panic and keep feeding too much or you'll have a big knot
Reply:i tried what you were talking about today and it came out looking pretty good, i will post my progress here soon, helps a lot when your not feeding from 12 o clock to 6 clock, feeding from 9 o clock to 6 clock helps a lot.