capping 5g pipe tig/inspection

admin

OK.  I've been out of the pipe trades for a while.  I need work and may have to get back in it.  The only issue i am having is puddle capping with tig.  I was never great at it to start.  I was a stick welder that could tig good enough to get by.  In practicing im having hell getting a cap on.  I can put a pretty one on with 2 1/8th filler rods using 1/8 tungsten.  But, using one filler rod leaves me low and makes it hard not to undercut the sides.  I am camping on the weld which isnt helping.  I can only assume i need to let it cool some and hope to get it fuller, although i know it's flush.  Im beveling 6inch sched 40 and running tig and stick roots with 7018 out.  The cap on tig out is making me cuss.  I walk the cup but am becoming more interested in free hand due to it's importance.  I need some tig hands to chime in here and get me back on track.  Also im a new CWI.  Any advice on where to find work or just how to get into inspecting locally.  I'm trying to give my wife and family the life I didn't have with an old man on the road all year.  Any positive imput would be appreciated
Reply:I would try running a little less heat, less side to side movement, moving faster or like you said let it cool a little more in between passes to help with undercut on the toe's... I also suggest the "tig finger" for free handing...  One thing that I have learned is that the cap requires sort of a sixth  sense all most...you sort of have to feel where to stop because the heat will move beyond that point and create that undercut..     I am not a pipe welder but i am busting my *** trying to learn...Last edited by DemonSpeeder; 11-13-2012 at 12:29 AM.Lincoln pro mig 180Lincoln Square Wave Tig 300/wp 20/home built water cooler Victor, Purox, Harris, O/A welding/cutting setupsVintage Craftsman drill pressVintage Craftsman/Atlas 12"x 36'' lathe7''x 12'' w/c band saw Everlast 140 st
Reply:Agreed.  Funny you should mention that.  I just got my first finger the other week.  I know the sixth sense your talking about.  I'll be working on it and thanks for the input!
Reply:What amps are you welding it at? Why use two 1/8" filler rods, because the puddle won't follow the arc arcross the bevel? Trying to fill/cap with one pass? Need alot of info before I can help much. Alot of guys have trouble with undercut from moving too slow and over heating the steel, so maybe try to move faster. You can do this by taking bigger "steps" while walking the cup or just move the torch side to side faster. A big cup will help walk across the bevel with less torch movement.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Im not capping in one pass lol.  That's my fault i should have gave more info.  Root goes in 1/8 with that size gap or bigger(ive been trying the backfeed technique for the bottom, hate it) with no problem.  I seem to fill it nicely in about 3 fill pases after the hot pass.  I have been using 1/8 for the filler and to give me more coverage on the cap.  Like i said before it's like i cant get the width or heighth unless i use 2 rods.  2 rods puts on a slick cap but i know i need to get it in one.  It does seem like i am forcing the puddle over to the bevel edges or getting there fine but don't have the heighth.  i can get by with a 2 bead cap but puddle capping is rough.  I'm not the best pipe welder but i know enough to know something is off.  I just dont want to get on a big money job and fail having an all tig joint or being too slow to handle a good stainless pipe job.  I've looked all over the web but i cant find a good vid of someone doing it with good arc shots.  They all seem to prefer 7018 out as i do myself but its not always gonna be that way.  To put it slimply, it just doesnt wanna stack!  I'm considering going into the waiter field im so disgusted.  Certified pipe welder cant get a nice puddle cap the right way.  FRUSTRATING  I'm capping at around 115 ampsLast edited by bluelightman; 11-13-2012 at 09:56 AM.
Reply:115amps seems too low, usually walking the cup with 1/8" filler I use 135-150amps (don't want to burn up the torch). When washing over the filler it will prob try to burn back, just push it into the puddle with steady pressure. Go fast over the center of the weld and get the puddle to the edge of the joint and you will see it fuse-do the same thing going the other direction. I think your problem is putting too much heat into the steel from a slow travel speed and low amps so try higher amps and see how it does. Also make sure the steel is ground clean about 1/2" past the bevel, if there is millscale it doesn't want to fuse well and can cause undercut.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:[ame]http://www.youtube.com/watch?v=S7Klef4BM4g[/ame][ame]http://www.youtube.com/watch?v=WSnj8AASuFs[/ame][ame]http://www.youtube.com/watch?v=SP5NZNaLELA[/ame]Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG
Reply:Pug!  Huge help buddy. i've just been on this lay wire take what it gives kick and it wont cap like that.  I went up to 130 and i could really stack a puddle.  I had some good runs but at times im struggling keeping the rod in enough to fuel the puddle.  I should get this tight in the next few days to a week or so.  Any tips for keeping the rod in a good feeding position.  I dont want to just jam it to my tungsten.  Although im not lay wiring as much as i am replacing it where i need it in the weld pool.  Thanks again man HUGE help.  I knew something was off and the heat really let me put some wire in the puddle.  im going to apply this to filling as well.
Reply:This is how I like to feed filler. Lets you feed wire into the puddle without getting sloppy like when holding the  wire near the center and "floating" your arm. Also, sorry about the ugly weld on this pipe it was my first 6g..its the only pipe I have at home to show how I feed the filler. Glad I could help  Attached ImagesLast edited by SquirmyPug; 11-14-2012 at 01:23 AM.Airco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG