Flux core and pipe

Date 03-02-2008 10:59

Time......

Flux core is not great at stepping gaps, solid ain't much better. Why work it when you can use a 6010,6011 that will tie it in, penetrate, and offer no effort fusion three or four times faster? That gives you a solid base to lay your high strength beads quickly.
just my opinion
Tommy

By Lawrence (*****)

Date 03-02-2008 14:55

Short circuiting GMAW will work nicely for open roots on pipe. There is also a modified short circuit process called STT (surface Tension Transfer) by Lincoln and RMD (Regulated metal depositon) by Miller..

These short circuiting root welding processes do require a good fitup and are less tollerant of missmatch. But they can put in sound root passes in all positions.

Also these processes have a limited viability outdoors. It is often just much easier to run a stinger and a work clamp out on that muddy, windy and changable worksite than it is to bring out a Mig unit or suitcase.. Although sometimes it is done.

There are quite a few indoor fabricators who are going the GMAW/STT/RMD route to lay in pipe roots.

By welderdude (**)

Date 03-02-2008 22:56

me personally, I know I can weld a gap no problem with stick. flux core or mig, you never know what's gonna happen next!

By swsweld (****)

Date 03-03-2008 02:15

GMAW can be used for open butt root pass on pipe with excellent results. It is not uncommon for pipe shops to roll the pipe with positioners and deposit the metal from 10 to 12 o'clock. Faster than 6010 and with a decent fit and the right parameters the results are a wedding band.

By wyndworks Date 03-17-2008 01:08

Well, thanks for the info. I just certified 6G and now I am trying to qualify my welds. Testing and real world welding are not the same to me. If I had to weld 6G in the field right now I would be lost or at best really really slow. But it is getting better everyday and should be good by the end of the week. I was just wondering about the wire feed thing. I can weld very fast in any position with flux core amd mig and was wonder why no one talks about pipe and flux core or mig. You can't tell me that it is not just as strong as any other welding because I have welded buildings together with my LN-25 with no problem and filled larger gaps than I will ever face with pipe. I am just trying to learn all the time. I work for myself and time is money when you do that. Anytime I can save time I try to go with the best process available for the job at hand.

By Tommyjoking (****)

Date 03-17-2008 09:32

wow .....

that is such an honest real world post...not making fun brother...I mean it. When your trying to choose how your gonna bid and build something the process can make or take money from you and thats real. No technical spec nothing bs here.......look at your joints, count them up, and figure the fastest/cheapest way to fill them up. Unless you have a serious strength TESTED spec to meet....rock and roll..what will get it done best. If you got a serious build joint with a a qualified spec to meet....well research it out and figure out whats gonna be the most effective dollar per dollar per inch of weld,,,and run with it...but no matter what meet or exceed the spec on every job PERIOD...you won't have anything to worry bout then. One of my greatest mentors said to me "build it like you never want to see it again".....that fellow put ALL his competitors within a 75 mile radius out of business in short order. take that for what its worth to ya

Tommy

By Tommyjoking (****)

Date 03-17-2008 09:48

reply you guys...this is actually a very valid thread.....all those guys who have suitcases sitting on the back of the truck.....50 mph wind and they got to lay that root to finish it and go home today.......why not.......I cannot think of a good reason why not except for the difficulty tying in an open root with flux core without inclusions over lots of inches....what about straight wire and a LOT of gas and a big cup...?
Cmon that mig has to be able to beat out that 6010/5p or a hippy rod. cmon you pipe guys ....tell us why not!??????

By hurricunning (*)

Date 03-17-2008 15:17

We are using Dual Shield wire (Lincoln G80M with C25) on pipe (16" to 24") all day long every day here outside, in the wind, snow, rain and mud. For bad weather we use HexHut tents strapped on the pipe, if it is calm out we seem to be abe to get away without much shelter. Very little porosity has shown up so far and minimal if no other weld defects due to the wire process. We are doing the root and hots with 8010P1 though. Most guys have Miller Extreme VS machines (supplied) but some have Lincoln LN25s. Both seem to work just fine. A guy could be doing open roots with hard wire anywhere but the fitup would be a more critical. Fittings to pipe typically have a lot of high-low here and hand prepped tie ins also have a lot of varriance in gap/land/bevel/high-low. Wire roots on the bottoms would be more difficult no? I don't have a lot of experience with hard wire on open roots. Does anybody do it out in the field? STT maybe would be more valid in that case.

By Superflux (****)

Date 03-22-2008 13:34

FCAW on pipe????
1) First and foremost in a word....TRADITION!!! (Grandpa never wire feeded no pipe!!!!)
2) Bulk of the wire feeder, draging from place to place, is a major pain. Also consider having to keep contact tips and other spare parts handy, it just can't compete with the lightweight portability of a stinger and rod pouch when in the field.
3) When using a FCAW or GMAW gun, one of the main things is to try and maintain as straight of lay out for the liner assymbly as possible. Due to the inhehent necessity to articulate the angle of the gun on a fast and continuous basis, this is not a good choice for small to medium diameter pipe in a fixed position...say under 24". Nothing is more frustrating than putting in a X-ray root bead and having the wire start sputtering and splattering right on the tie-in because you had to put a kink in the cable to get a proper angle of the dangle to reach that point!!!

OK, with all that being said, a wire feeder strategically placed (overhead or at least elevated off the floor) on 1G pipe (manual roll out wheels or power driven rollers) GMAW root and fill or even GMAW root with FCAW fill & cap (killer pound's per hour production on heavy wall), will kick "A" in production shop envirnment over SMAW.

Bucyrus Erie, the maker of the worlds largest draglines GMAW 0.045" their booms. The booms are a lattice design of 10" & 20" pipe with about 2" wall thickness. Root penetration is 0- 1/32" max, and the entire welding process is under continuous UT and other NDE surveillance. These machines operate under phenomenally severe environments. > 100 F in the summer and < -40 F in the winter. The point sheave of the boom on a B/E 2570 walking dragline would be about 350' from the operator, with a cable and bucket assembly including payload supports in the neighborhood of 300 tons and swinging hundreds of cycles per 24 hrs, day after day. These are not gentle swings and payouts of cable like setting a 300 T load with a Mantiwoc Ringer, but HAULIN' "A"!!!!

So, yes, semi-auto processes can and are used in field work on critical pipe components!

I personally am not a fan of these processes in the "pipe trades" out of a shop and stationary, controlled environment. Just too many things to go wrong.
Thats my story and I'm sticking to it!

One more thing from your post, cranking up the gas flow often causes sheilding problems due to excessive turbulance sucking in air. Years ago when I was a mine maintenance welder, we used a lot of FCAW-G in the field. Some locations like load out chutes under the silos with intense natural air flows made for some long and frustrating shifts battling the wind vs. gas coverage............