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Up Topic Welding Industry / General Welding Discussion / Flux core pipe welding expert
- - By JSTOREY (*) Date 02-05-2006 15:11
I have some question on technique for the fill and cap pass.Cap is a weave.
Where I work the root is tig and filler and cap is flux core on carbon steel pipe.Pipe size range from 6 inch to 20 inch.

Welding machine:
Miller-Invision 354MP DC inverter Arc welder
Welder has 15 programs-its set on mig rev.polarity

Miller wire feeder
Gas is 75/25 set at 35-40
wire is .045 Select

On slip on flanges done flat on a turn table,welds are slick.One pass on the inside and three on the out side(single pass then 2 stringer cap)
All is good on the flanges.Im around 28 to 29 volts,3.75 to 4.0 wire feeder goes from zero to ten.

The problem is but welds,everything is exceptable for the company,but not me.:)There are no worm tracks or holes in the caps.I figure there has to be some one out there that has it down.I have over 30 years exp.
My email is Bullet3prtcnet.com

Thanks for any and all help.
J.Storey


Parent - - By Mike Brace (**) Date 02-08-2006 14:57
What is it about the apperance of the weld that you are not happy with? If you can tell me this I should be able to make some suggestions.
Parent - By jwright650 (*****) Date 02-08-2006 15:19
I agree with Mike,
The reason this thread has been sitting here without any replies is probably because the poster didn't say what they were unhappy about, in particular, and also, nobody probably wants to step up and admit or proclaim that they are an expert in FCAW. There are lots of knowledgeable folks who monitor this board and have lots of experience, but people tend to shy away from threads asking for expert opinions.
We heavily use FCAW 100%CO2 on a daily basis and have had obstacles to over come with regards to appearance and profiles, so we also "might" be able to add a suggestion, depending on the problem they are having.

my $.02
John Wright
Parent - - By JSTOREY (*) Date 03-04-2006 16:14
Sorry about the expert thing.In my area most are experts even if they haven't ever done it.:)

Right now Im on 12 and 14 inch pipe,tig root flux core filler and cap.Im around 27 to 28 volts

The filler looks good,on it I burn into the walls of the pipe.Which makes it alittle wider for the cap.I also leave the filler under flush.

The cap:I have tried a weave,pauseing on each side,also tried U patern.
The weave pattern has a rough look to it.The U pattern is slicker.I was expecting more of a 7018 appearence.Where I work everyone is more then happy with the appearence of the welds.But Im not.

Any help with techniques,settings for the welder,anything.I will give it a shot.

Thanks,Jud

Parent - By dasimonds (**) Date 03-04-2006 21:44
You still haven't stated what you find objectionable about the welds.
Dale Simonds
Parent - - By - Date 03-04-2006 23:19
Jud,
To be perfectly honest, I think you might be just a little too critical on yourself, but on the same hand I admire your desire to achieve excellence. You are to be highly complimented on that. It appears you are using correct paramenter and techniques for the FCAW process. Again, I admire your persistence to achieve a higher degree of excellence, and that might come from continued usage of the FCAW process. As most FCAW welders will attest, it is a very easy process to master, but it is not an overnight thing. The most important thing, in my opinion, is to continue to try different techniques until you find the technique that works best for you as an individual. Your desire to be the best you can be says a lot about your character. If I were a shop foreman, I would be proud to have you as one of my welders.

Chuck
Parent - - By rodofgod (**) Date 03-04-2006 23:41
Hi All!

Got to agree with the rest of the posts,FCAW process take's alot of practice to generate good looking welds equal to MMA !

Keep practising and hopefully, you'll come up with a technique that gives you the weld your looking for!

Regards


Parent - By EU Engee Date 03-11-2006 21:34
In this situation shall to help simply to do exactly in both melting in lines
paralely situated small rows around the pipe. Leading the weld pool from
hour 2 towards hour 1 you will obtain better look of external surface the weld - of course if rotating is accessible - isnt it?
Baby-grinder, not so thick grinding disk at not shaking hands at all.
Things can be easy if someone may immagine, its works.
With best regards
Well wisher
Parent - - By cheeseandchive Date 03-19-2006 13:40
hello, i'm new to this site and this is my first posting so here goes. in scotland we use a lot of flux-core and i've found that the best settings for capping using 1.2mm (.045 " i think) are 22.5-23 volts and around 245 inches per minute on the feed. point the wire right into the centre of the pipe and keep moving at a constant speed going rapidly from side to side. if you think you're about to lose it onto your boots pull back 5mm and this will cool it down a bit due to inductance (pinch effect). between 10 & 2 you can drag it a bit just like stick. hope this helps
Parent - By vonash (**) Date 03-19-2006 16:18
I agree with Chuck.
Parent - - By JSTOREY (*) Date 01-13-2007 13:41
Thanks for the help.
Going to try different wire.
Hobart Fabco 825,anyone have any experience with it?
Also,what are some of the better FCAW wires to use on pipe?
Thanks,JStorey
Parent - - By Blaster (***) Date 01-13-2007 21:02 Edited 01-13-2007 21:53
What AWS classification is Fabco 825?  I didn't see it here:  http://www.hobartbrothers.com/products/ with a product search.

Keep in mind that when talking about welding setup that voltage can be a tricky term to use.  When trying to make comparisons, differences in lead length and size, indicator errors, what type of voltage is actually being refered to, and soforth can cause mix-ups.  Probably best to use wire speed in actual measured inches per minute as the primary reference.  CV voltage adjustment is pretty much a more or less thing to achieve a suitable arc length and slag follow.

The E71T-1 and E71T-8 (gasless) both seem to work well for butt joints on heavier pipe.  While I don't have personal experience welding with either on production pipe joints (lots though on other-than-pipe), I have conducted certification tests for many welders using those wires on 8" Sch 80 6G tests.  With a good welder holding the gun, the welds go in fast, flat, and clean.
Parent - - By JSTOREY (*) Date 03-10-2007 16:08
Sorry about the wire,Wire is TM-770
Working on 5",6" and 8" schedule 40 cs pipe,w/tig root.
Still working on getting the cover pass(weave cap)to look real good.lol
JStorey
Parent - - By Kix (****) Date 03-13-2007 16:26
Yeah 28 to 29 volts thats your prob right there.  Might work good in the flat, but for out of position pipe u wanna go down to like 22 or lower like what was said above.  It really depends on your style and technique on where you set the machine.  Play with some colder settings and you'll be amazed.  Don't forget to turn the wire down a bunch to. 
Parent - - By js55 (*****) Date 03-13-2007 17:23
J,
I don't think the parameters or the wire are your problem. You mentioned yourself that your flat slip ons are excellent. The difference, it seems to me with your grooves is the concavity of the weld when you start your cap. You have extreme concavity with a single pass flat fillet on slip ons.
I suggest reducing the amount of fill you are using. And concentrate more fill with your cap. This way your oscillation is not critical, or even much necessary except to spread the puddle and tie in the sides.
I used to do this all the time with the sizes you mentioned. In fact, on std walls I would put just enough fill in to keep me from blowin holes in my (single pass) GTAW root, and then essentially fill and cap at the same time. Your caps will be flawless. And a smooth and ripple free as a babies butt, with a beautiful and symetric convexity.
This also has the advantage of increasing the amount of weld metal deposited at higher wire speeds, increasing production.
Parent - - By ZCat (***) Date 03-15-2007 00:11 Edited 03-15-2007 11:36
We did a lot of DualShield when I worked at the Veco shop in Anchorage. We were using Lincoln wirefeeders, LN25 I believe it was. It took me a long time to get the hang of it, but I finally got pretty good at it.
For the cap on a position weld, I found around 27.5 volts was about right. I would set the wire speed around the same as the volts: 27.5 volts, 275 wire speed or even 10 or 20 less at times. You have a different wirespeed set up. You want to go by the sound, set the wirespeed so the puddle is making a 'ssshhhhhhhh' sound, if it's crackling the wire is too high. Mind you, this is just for position welds. On the rollout welds on the positioner I set the volts on 32 and the wire on 550. Smokin' hot, but slicker'n a minner's d!@k. Pretty tough on the welding shirts, though. 

For your weave motion, you want to go back and forth pretty fast to keep the whole puddle fluid. If you go slow, it's gonna look like crap. You can't really use the same weave as a 7018, it doesn't come out good. You want to go side to side real fast, and don't go up in a big step like with 7018, you want to take baby steps.

That said, you really can't make DualShield come out as pretty as stick, it just don't work that way. They use DualShield cause it's fast, not cause it's pretty. And always remember; ugly shoots, too!
Parent - - By js55 (*****) Date 03-15-2007 13:16
ZCat,
I would disagree. You can make 'Dual Shield' absolutely beautiful. If welded with practice you can make your caps with this process almost completely rippleless, even out of position.
But I would agree that you don't think of FCAW in terms of stick. With stick the rule of thumb is hold on the sides and let the middle take care of itself, or a U shape weavethat accomplishes the same thing. You don't do this with FCAW.
Parent - - By JSTOREY (*) Date 01-19-2008 11:21
js55
Can you elaborate on the technique you use?
Thanks,JSTOREY
Parent - - By js55 (*****) Date 01-21-2008 14:29
I always used a simple rapid zig zag pattern, though with the wire speed/amps slightly increased in relation to the voltage. This helps on the bottom. I would concentrate on the solidification front at the back of the puddle trying to maintain a single puddle flow throughout. Its almost as if you are dragging the entire puddle behind you.
Starting at the bottom I point the gun at ~15 to 30 deg angle leaving my hand essentially in the same orientation while moving the gun tip so that by the time I reach the 4:00 position I am almost perpendicular to the pipe. I maintain perpendicular (or even a slight leading angle) until I reach the ~2:00 position where I start to lean over the pipe pointing the gun in a trailing angle untill I stop at the top.
Parent - By js55 (*****) Date 01-21-2008 14:46
Also, leave a concavity on your fills (the better you get the more convavity) and allow the puddle to fill to convexity for your cap. if you fill too high its hard to keep the cap from rolling over on you and sagging in the middle. Plus, quite often if you fill to flush or almost flush you'll have a slight edge that can have slag trapped in it (that doesn't brushout easy) and it will trap as the puddle flows over it, the only good solution then is to make sure your arc runs right over the top of the edge to burn it out, which means that your cap will then be too wide and you 'll again get that roll over and middle sag look. Not to mention that burning it out is risky. If you fill too much its almost easier to grind back out your concavity.
Parent - By Aspirate (**) Date 01-21-2008 05:59
i agree with the dual shield.  long ago my instructor kept on telling us to pause on the sides just like stick. good thing fcaw part of class was short.  i got the best results without him looking and without holding on the sides.  you're right about the appearance.  to me, it's the process that produces the smoothest weld bead (even smoother than gmaw & gtaw)..
looks like forged metal when done right!    
Parent - - By weldgault (**) Date 01-19-2008 22:38
I think that Kobe is the best wire on the market.  AT 29V and 220A with 3/4" ESO, the flux will peal off by its self and I have never had this wire worm track, even with a 1/4" ESO.  Have Taught over 500 Welders to qualify for 6GR, Flux core .045 all the way, without one falure.  John
Parent - - By jbeard (*) Date 01-23-2008 23:49
ok,ill let you in on the trick to welding flux cored wire,when you are caping the trick  is not to pause on the sides,it will make it lumpy looking,the weave needs to be extremely tight using side to side motion,you need to to also do it fast.the finished product should be slick so that one cant even see a weave,it really looks good if done right.hope this will help you out some bro,keep us posted on how this works.
Parent - By jesusno2 (*) Date 01-24-2008 05:46
we run esab .045 dual sheild wire straight co2 gas it works pretty good my favorite setting with the miller 350p id 24.9 volts 304 wire speed it's a pretty good horizontial setting and a beautiful vertical setting. this wire will worm track if your not running on pretty clean metal but i really like it. it's taken me a few months to get used to it. is all flux core wire as easy to use as the dual sheild stuff?? I have litte exp with fluxed core wire.
Parent - - By JSTOREY (*) Date 01-25-2008 00:50
Thanks jbeard!!
I will let you know.I have been pausing on the sides on the cap and your right its not slick.
On volts and wire speed:a good place to start?Pipe is 6"sch40 up to 12"sch40
Thanks for everyones input!!
JStorey
Parent - - By JSTOREY (*) Date 02-03-2008 19:35
The tight weave worked real good with the filler about 1/8 below flush.
I had to change up the above technique alittle based on fit up.
What shade welding lens is everyone using??
Thanks
Parent - By SPARKYCA (**) Date 02-03-2008 20:35
The last time we welded up some pipe spools with .045 dualshield, I changed from a #11 lens to a #12 and It seemed about right. 
Up Topic Welding Industry / General Welding Discussion / Flux core pipe welding expert

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