Tig Root

Date 09-03-2008 15:10

no no your doing it all wrong use a 5/32 gap with 1/8 wire, if its biggerpipe use a 3/16, if it has to have hi lo and its going to be done in position put the hi lo on th bottom.
when you go to tack it put a bridge tack on top, good tack on bottom bridge takc on one side (onnly tack one side). when you go to weld it start on the side woth no tack bottom up, when you get to the top get as close to the birdge tack as you can. dont cut it yet. now go to the other side come up to the tack on the side cut the tack out continue up the top now you cut the tck on top feather the tie in. close it up. for your hotpass go up about 40.

By Roadhand (**)

Date 09-03-2008 19:56

I agree with juve11, his method will keep the gap from closing up , When you look at the the fit it will seem to large, just put the shield down and weld , it wont seem so wide while your welding .

By medicinehawk01 (**)

Date 09-03-2008 23:33

Using a decent gap, 5/32" is the way to go, but I don't agree with bridge tacks. I don't use them. Tack up in 4 places, feather your tacks, examine the gap critically and put the tightest quarter(of 4) where you would want to weld this one 1st. Some say it is easier to go from 6 o'clock to 9 o'clock or 6 o'clock to 3 o'clock, whatever, i usually weld the seemingly more difficult quarter first, this is where I would put the tightest quarter.
Run hot-125 amps and be deliberate, not hurried. Weld the bottom quarter, then the other bottom quarter and then either of the top two quarters until the root is in. To me, you need to minimize the ocillation of the tungsten concentrating the heat right on the rod as it is melting. I firmly believe in "walking-the-cup", but even if you have not much experience it shouldn't matter as long as you don't run the arc up the side of the bevels. Crank up your heat 20-25 amps and put in your hot pass.
You can usually tell if you are getting in good by watching the puddle carefully, it should be swirling and ofcourse , always use a sharp tungsten.
My 2 cents.
Be well,

Hawk

By K.Sexton26 (**)

Date 09-04-2008 04:33

the reason your getting a lumpy root is your gap vs. wire rule of thumb is 1/8 gap-1/8 wire ect. thats what works for me. do not use bridge tacks inspectors wont tolerate that on XRAY welds plus it takes more time put them in right the first time and go on with it, thats a bad practice in my opinion. put 4 equal size tacks at 12,3,6,9 feather edge them lightly, to much will make it harder to tie in. walking the cup im assuming keep your tungsten sharp and straight in and stay on the wire and oscillate just enough to tie the walls in,if you go to far up on the walls you wont get good penatration because all your filler metal is on the bevel and not going in the root. set your heat were you can walk as fast as your skill will let you. when watching the weld pool make sure you have a line in the center of the weld it will be a faint line behind your cup if you do it right it will be there ever time, also look for the devils eye in the weld pool its a dot sould be swirling around the center of the weld pool counter clockwise but if its swirling clockwise the root not going in right. when your tiein to your tacks stand your wire up a few degrees it will make better tieins. remember if you go to slow on your root or hotpass you will get suckback from to much heat input. shoot for solid wedding band 3/32 to 1/8 ID rienforcment, i usually run 90-95 on the root pass 1/8 wire, 1/8 gap,1/8 tungsten or u can go with 5/32w,gap,and tungsten. hope that helps

By vagabond (***)

Date 09-04-2008 05:12 Edited 09-04-2008 05:16

I agree with an 1/8 filler metal and 1/8 gap. As an inspector I also don't buy bridge tacks, for any reason. I would say somewhere between 80-95 on your root. I oscillate no more than the width of the filler on the root. 15-25 more for your hot pass and oscillate twice the width of your wire. I like to make my tacks smaller feather them a lot and consume them as I do the root but that's just me. I see a lot of people use a wide weave on their hot pass. If you keep it tight it pushes the root in nicer I think. That's what I was taught and it's always worked for me. I'm figuring you are on 2-6 inch pipe for this test so I'd also go 3/32 wire and gap and lower heat for a 2" coupon. Also I'd drop to 3/32 on my tungsten. Small pipe=small tungsten, there again it's personal preference but I think it runs better that way. Some guys use 1/8 for everything.

By K.Sexton26 (**)

Date 09-04-2008 05:43

vagabond thats a good point on the hotpass tech. i watch alot welders put good roots in then suckem right back out because they go way to wide on there hotpass, then they got that puzzeld look what did i do. i never have figured out why welders use 5/32 gaps and 3/32 wire for puttin roots in it always looks like they keyholed the root in or as some call it backfeeding seen alot bust test like that but to each his own.

By juve11

Date 09-04-2008 09:17 Edited 09-04-2008 09:26

well I also work as an inspector and bridge tacks are no problems for me or any other inspector I've worked with as longas you keep it in the bevel. 1/8 gap, 1/8 wire sounds to me like your welding tubes. Justwashover it. Where are you located I'm in Texas. I've worked the east coast and them boys can't handle a good gap.
? what do you do when you have 1/4 " hilo with 1/8 gap.
Xray of no xray doesn't matter your grinding those out.
If you put 4 tacks you got 4 tieins, you use my method you get 1 tiein at top

By vagabond (***)

Date 09-04-2008 14:42

FWIW I'm certainly not the only inspector in my area who won't buy bridge tacks. I also won't buy a large gap unless there is no way around it. If you can't feed your wire from the outside or with a 1/8 gap depending on the spec., well then I guess your going home. Hell I can TIG a 3/4 gap if I want but it doesn't mean it's a good practice. For the record I am not a tube welder, never have been. I've been a Pipefitter/Welder for 20 yrs. I use small tack and consume them so when you use my method you only have one tie-in at the top too. I am located all over the west coast FWIW but right now I'm in Wyoming.

By K.Sexton26 (**)

Date 09-04-2008 15:27 Edited 09-04-2008 18:02

juve11,bridge tacks are a bad practice i think plenty of people will agree with me on that, im not going to get into a pissing contest or who can weld better. im from the east dont matter were your from the right way is the right way east to west south to north. i welded tubes,heavywall,and biginch pipe do it all the same way industry standard. if you are a inspector you would know bridge tacks aren't acceptable, i've went back and read some of your post, and if you were a pipe welder with any exp. you would know what a branch test looks like and how to weld one because thats happens on a day to day basis in pipe work even in texas. your not going to make a pipe test using bridge tacks the insector laugh you out of the booth and your buddy that taught you to do that, you couldnt been on any xray jobs if you think bridge tacks are acceptable. and i welded with guys that run excessive gaps the reason they do it cause they cant put a root in the right way the have to backfeed it. ive worked all over dude inculding TEXAS its done the same way. if a skilled welder puts a tig root in like its supposed to be done you won't be able to tell were his tacks begin and end. i guess you use bridge tacks when your puttin a root in with 6010 to. im callin bull***er, and to answer your other ? {what do you do when you got 1/4"gap highlo with 1/8 gap} my answer is weld it made plenty of them. and your method of tacking pipe is about ten times slower then the rigth way while your grinding them nasty bridge tacks out ill be cappin mine, mister inspector you sould know the CODES none of them allow bridge tacks unless you have a secret code book one just for texans! if so send me a copy and ill appologise, theres nothing wrong with 5/32 gap never said there was. good day sir!

By juve11

Date 09-04-2008 16:43

were talking tig not stick, ive never known anyone to put a bridgetack with stick,
i've just never took a branch test. Im sure everyone had their first.

By K.Sexton26 (**)

Date 09-04-2008 17:23 Edited 09-04-2008 18:02

thats what i was getting at man you dont bridge tack with stick so why would you with tig same principles. thats all im saying about this topic, my post was a suggetion for the guy that ask the question it was my take on tacking a cupon with tig that its and YOU took it offensive for some reason it was'nt even meant for you dude and you presist to keep smartin off to me this is a place for recieving and giving advice on welding topics not a place to measure our you no what get over it dude. and yes everybody has a first for welding test i was trying to give the guy that started this thread some advice.all i was gettin at if your an inspector like you said you are, gotta have atleast 5 years ex. as welder. i would think you made some branch welds by now or atleast seen some in all those texas plants were you been welding pipe.

By vagabond (***)

Date 09-04-2008 18:02

I hate to nitpick, really, but you do not need 5 yrs. as a welder to be inspector. I wish this was the case I really do but the spec says 5 yrs. experience doing code related work. I wish they would change this but until they do we will continue to have "shake-n-bake" inspectors out there. I worked with a guy who got his CWI when he was 20, go figure. . . . I asked him if he was welding in Boy Scouts when he was 15 or what??? I for one don't think the experience required is followed up on too much. As long as the check cashes. . . . just my .02.

By K.Sexton26 (**)

Date 09-04-2008 18:04

your right

By andrewsullivan9 (*)

Date 09-07-2008 06:34

Thanks for the help, will try a larger gap and slightly more power then, am just starting to get more consistent with my root runs now, but still having poblems around 6 or 5 oclock with the wire dropping out of the weld pool

By K.Sexton26 (**)

Date 09-07-2008 14:39

try using a smaller gap ! your wire won't fall thru your gap