Opent Root pipe

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Ok so how do I put my root in on pipe ???  My instructor says whip and pause the root.  How would you do it.   We are running 1/8 land and 1/8 gap.  with 1/8 6011 rods on DC.I tried leaving no land and no gap the 2 bevelled pieces tight together and ran a stringer for the root and burnt a key hole through.  This worked good until the key hole opened up too much....Maybe I should run it like I ran my plate ?  3/23 gap 1/8 land and 1/8 rod and run a small weave in and out of the keyhole ??Any tips would be appreciated.
Reply:Celloluse electrodes + vertical down = stovepipingroot gap 1.0mm to 1.5mmroot face 1.0mm maxgroove minimum 60°When welding, you should be able to clearly see the keyhole within the pool. Use manufacturer's recommend current according to rod gauge, and travel speed will be fast. Vertical down only for positional work.Good luck
Reply:We have to go vertical up.  Will this still work ?
Reply:that land sure makes a huge differance . we used 3/32 gape, with 3/32 root opening i was taught to move the rode only slightly not so much wipe and pause but just back and forth keeping a short arc length .only differance was we used 7011 ...ithink.... i know it wasnt 6011
Reply:Ok so I tried it again today...   I tried slamming the gap down to 1/16 and the root to 1/16 and running the 1/8 6011s as low as theyd stay lit.  I still blew holes.  I tried changing it up to 3/32 gap and land still blew holes....   To run a stringer my instructor figures id have to use a 3/32 rod.   He also told me im wasting my time trying to do a root weld on 4" pipe with stick as the heat will not dissapate as easily as it does on larger pipe.  He said pipe this small would have a tig root !Im not doing this as part of the class this is just something extra I am doing because I am ahead of everyone.
Reply:If your instructor said you can't root with 6010/6011 on 4" pipe, he is incorrect. It is done all of the time, both up and down, even on pipe as small as 3/4NPS. My root's suck on pipe this small, in part because I don't do it that often (I do TIG roots whenever I can, but work with people that prefer stick) I do agree that 3/32 rod is a better choice than 1/8 for the root. Use 1/8 (or 3/32 with a light weave) for the hot pass.For ASME procedures, it is almost always going up. API procedures usually go down. Down is faster and a bit easier to control the heat. Going up on 4" shouldn't be a problem.It sounds like you are working on 5G (pipe axis horizontal) or 6G (pipe axis inclined at 45 degrees to horizontal), so I would suggest that you use every bit of the 15degrees from the centerline you are permitted at the bottom and the top: start 10 to 15 degrees ahead of the bottom center, run to the bottom, up, then 10 to 15 degrees beyond the top center (total of 200 to 210 degrees... See http://www.sperkoengineering.com/html/Position.ppt for limits on positions). Mark the start point and stop point before you go. Then, for the other side, do the same thing, so you are starting and ending on the existing bead. This gives you some leeway to work the arc and get your speed. I also tend to shove the rod into the keyhole a little and make my whip a slight oval, rather than a plain forward/backward whip. On restart, start back on the existing weld a little bit, then travel in to open the keyhole. DON'T try to lay a lot of metal when you start and stop on the existing weld. If you do, you may find the hot pass tough to run without grinding.Starting a bit ahead of the bottom a) takes you off the most difficult point, and b) lets you not worry about the start being perfect. You are going back over it anyway, and if you need to hit it with a file  or grinder, nothing lost.
Reply:What are you running for amperage? You can change your electrode angle to open/close up the keyhole.When  you have it set right, you will barely have to manipulate the rod at all.
Reply:A quick correction, something I noticed I didnt put in the other post....  The pipe I was running on was 1/4" thick stuff.   Thats what he meant by not being able to run a root on it had nothing to do with the over all size.   Im practicing running vertical up.   He hasnt ran pipe vertical down.   There isnt much pipe work done here and what is done is usually vertical up.   The root is usually tigged on the thinner stuff...  So he told me to weld the 1/4" wall stuff to tig the root....Im going to try some 3/8" pipe tomorrow for vertical up...I ran all sorts of different heat settings...  To be honest I cant remeber the ones I tried....Last edited by Newfie_1986; 11-17-2008 at 04:06 PM.
Reply:We used to use 6010 3/32 rod with a 1/8" gap and i think a 1/8" land in 6Gthen fil and cap in 1/8" 7018. not sure which of the 2 rods were used for the hot pass.I recall changing the polarity after the root, but that doesnt make sence to me now as both rods are Dc+.Could we have used DC- for the root????I cant remember the ampage for the root but we were pushing the rod into the keyhole to get the nice loking bead on the inside and weaving in a "U" shape to follow the bottom of the keyholeGG
Reply:6010 runs best with the rod DC-- .for down.  tight gap and the heat 120-140ish, light up and hold the arc long till it heats up, then jam it in there and go with the rod pretty much at 90 degrees, if the hole opens up lay the rod over. At times when it's runnning just right you will get a bend in the rod because you've got it jammed in there so hard.Edit to add:  In fact when it's running right you should have the bend in it, when that happens you know your tuned into it and the fit up is good I'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.
Reply:You've just got to run the cellulose electrode downward  for positional work. The arc is too fierce for vertical up progression.DN100 STD WT pipe should be fine for stovepiping. For high quality work, GTAW or GMAW-STT would be a better choice though.Cheers and it's always good to experiment.
Reply:Originally Posted by chrispc66You've just got to run the cellulose electrode downward  for positional work. The arc is too fierce for vertical up progression.DN100 STD WT pipe should be fine for stovepiping. For high quality work, GTAW or GMAW-STT would be a better choice though.Cheers and it's always good to experiment.
Reply:Yes it can, BUT it's very slow compared to down.I'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.
Reply:all my passes were up the way.is it my bad memory that we changed the polarity?G
Reply:If you ran it up you may have left it reverse,  had a couple today that the gap was way big and no 4mm's around so I did them up.I'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.
Reply:Originally Posted by chrispc66Celloluse electrodes + vertical down = stovepipingroot gap 1.0mm to 1.5mmroot face 1.0mm maxgroove minimum 60°When welding, you should be able to clearly see the keyhole within the pool. Use manufacturer's recommend current according to rod gauge, and travel speed will be fast. Vertical down only for positional work.Good luck
Reply:Originally Posted by Newfie_1986Ok so I tried it again today...   I tried slamming the gap down to 1/16 and the root to 1/16 and running the 1/8 6011s as low as theyd stay lit.  I still blew holes.  I tried changing it up to 3/32 gap and land still blew holes....   To run a stringer my instructor figures id have to use a 3/32 rod.   He also told me im wasting my time trying to do a root weld on 4" pipe with stick as the heat will not dissapate as easily as it does on larger pipe.  He said pipe this small would have a tig root !Im not doing this as part of the class this is just something extra I am doing because I am ahead of everyone.
Reply:Hey guys,           Whats up with all the down hill root talk? The only time I've encountered procedure requiring down hill was natural gas pipe. I imagine the codes have been updated\changed by now,but when I was working natural gas lines in the late 80's, anything smaller than 4" was to be oxy\act welded. I apprenticed under this hard lived, skinny red-neck that appeared to be 65+, your basic old-crotchety bastar**. He could take a oxy/acty torch and weld out a valve station, 10 to 16 joints, the root to cap would be pretty as any tig I've ever seen. That's core talent!Miller TrailBlazer 251Miller HF-250-1Miller MaxStar 150 STLHyperTherm PowerMax 380 plasmaLincoln PowerMig 180Millermatic 252Miller Diversion 180
Reply:Most onshore and offshore gas transmission lines require productivity, hence VD root progression with cellulose consumables.There are no set rules, any process / consumable / progression can be used provided consideration to grade of materials and service is made, and the WPS appropriately qualified.It is also worth noting that higher yield strength CS pipe may not be suitable for cellulose consumables in the root, hence the development of GMAW-STT specific to root passes. This is used exclusively VD progression for root passes.Like cellulose, you can do VU if you desire, at great increase in overall production costs.Cheers and end of rant.....Last edited by chrispc66; 11-25-2008 at 10:24 PM.
Reply:If I read you're question you are doing vertical up stick? I did a test today for pipe 5G and 2G on 150mm pipe (roughly 6"). I use a 2.5mm rod bent into a vee to set my gap, tack it and then grind the rod out. my land varies between 1.5mm and 2mm ,sometimes 2.5mm if I stuff up.I used a 2.5 mm Kobe52LB low hydrogen for the root, with the rod always pointed at the centre line on DC- and on my machine at work 62 amps. Hot fill was 75 amps and cap 62 amps.I just poked the rod in and listened to it, you (well I do) have to hear the sound of it going through, it is quite loud, a friend describes it as a roar but not to me, maybe we hear differently but it has a definate sound of it's own. No weaving on the root unless the keyhole got too big then I came back a bit on the side of the vee till it stabilised. It passed visual OK and now has gone away to be X-rayed. It worked for me.
Reply:2.5mm rod = .100" or 3/32 rod.Just for the metricly challenged.David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Clive, do they not use the 55U anymore in Aus?  I used to love that rod for the root, over here at the moment and have only seen these 52 about.I'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.
Reply:Wirehunt,Yes they do have the 55U, we have them at work, I used a Austarc 77 today, low hyd. but it runs on DC+ or A/C beautiful either way, hadn't tried them before, loved the finish, it was horizontal, great rod, very quiet. Where abouts in NZ are you?clive
Reply:Have a look on the pack and see where there made.   Sounds like the same place the 16TC is produced.I'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.
Reply:Yes they are, they are made in NZ for Austarc by Weldwell in Napier. Weldwell took over the Phillips line and make all their old rods, kept the same numbers just put a prefix on some of them, I will use the 77 in preference to the 16TC and that is a pretty good rod to use as well.Clive[QUOTE=wirehunt;228523]6010 runs best with the rod DC-- .for down.QUOTE]Just to make you aware, that even tho downhill roots are run with cellulose rods with electrode negative in europe and evidently New Zealand, you will very, very seldom or never see that done in the United States. Electrode positive.JTMcC.
Reply:[quote=JTMcC;230371] Originally Posted by wirehunt6010 runs best with the rod DC-- .for down.QUOTE]Just to make you aware, that even tho downhill roots are run with cellulose rods with electrode negative in europe and evidently New Zealand, you will very, very seldom or never see that done in the United States. Electrode positive.JTMcC.
Reply:Interesting JT cause the 6010 is a much nicer animal run DC-.   Do you know of a reason for that?I'd rather be hunting........USE ENOUGH HEAT.......Drifting around Aussie welding more pipe up, for something different.....wanting to get home.
Reply:It's interesting this DC+ DC- thing. I use both a lot and being prone to senior moments frequently forget to switch leads. It doesn't make heck of a lot of difference really I find I can weld with either but for test pieces I have to make a conscious effort to remember polarity but have forgotten anyway and still nailed it. But my experience with 6010 is nil.
Reply:Originally Posted by Newfie_1986I tried leaving no land and no gap the 2 bevelled pieces tight together and ran a stringer for the root and burnt a key hole through.  This worked good until the key hole opened up too much....
Reply:[quote=JTMcC;230371] Originally Posted by wirehunt6010 runs best with the rod DC-- .for down.QUOTE]Just to make you aware, that even tho downhill roots are run with cellulose rods with electrode negative in europe and evidently New Zealand, you will very, very seldom or never see that done in the United States. Electrode positive.JTMcC.