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Up Topic Welding Industry / Technical Discussions / stainless tips
- - By Sourdough (****) Date 05-10-2008 18:41
I am a man that started cash out of pocket and have welded on mostly carbon all my life, (since the age of 14), I have heard of gas booms in other places, and know that there is a ton of work for ss certified individuals.

Basically I am asking this: for a seasoned veteren welder, how difficult would it be to learn and hang with the wolfpack on stainless lines? i am assuming the root would be difficult?

So far I can make a stainless handrail, get my drift........?
Parent - - By mechan (**) Date 05-10-2008 19:09
tig or sticked on the stainless lines? what type of stainless?
Parent - - By Sourdough (****) Date 05-10-2008 19:30
have no idea. Figured you would crash me a course.......
Parent - By mechan (**) Date 05-10-2008 19:52
This is my opinion on stainless, (for what it is worth), hah. If you are a pretty good hand with carbon there is a very small learning curve to overcome. Thin walled stainless tests on the jobs I've been on were usually a fused root and then tig'd out, the heavier walled like schd 40 and above were tig'd root and 309 out. If you are use to heli-arcing carbon pipe the switch to stainless isn't going to be an issue.
Parent - - By jrw159 (*****) Date 05-10-2008 23:57
SD,
  You will be just fine. No problem hanging with the pack. The only thing I would say is, it is a different animal, but I know you can follow code and procedure, so again, you will hang with it just fine. IMO FWIW

Good luck,
John
Parent - - By swsweld (****) Date 05-11-2008 03:44 Edited 05-11-2008 03:57
I'm no SS expert SD but it's all uphill. Unless there is a backing ring involved (which I doubt) it will be a GTAW root pass. Depending on the procedure it could be tig all the way out or a tig/stick combo. The stick on the bottom of a 5G weld will be a little choppy (like ocean waves but not in a good way) at first until you get your technique figured out but the top half welds just fine. BE CAREFUL. The slag on a SS stick weld will pop off without warning and always aims for the eyeball like a magnet.

The SS tig root is different than CS because it requires a back purge. It's not rocket science but will need to be done correctly or root and hot pass will be disastrous. The actual welding of the  root pass is not too different on SS that CS but the purging is critical. There was a recent thread on here under "SS sugaring" I think if you use the search feature.

There is another method called solar flux for root pass instead of using argon or helium but I have only used it once and was not too impressed with it. I don't think it is all that common but I could be wrong.
I've also welded bi metal boiler tubes that were CS tig on root/hot pass and SS the remainder.

The wire is usually ER 308 or 316 for SS to SS and 309 wire/rod for SS to CS.
Also it is not good to use disc and brushes on CS then use them on SS. It will contaminate the SS and possibly cause the SS to rust.

If you excelled in the other rod/wires/processes I'm sure you will with the SS also Good luck with it.
Parent - - By aevald (*****) Date 05-11-2008 04:30
Hello Tim, there are a considerable number of light-walled SS pipes that are welded with downhill-specific type electrodes, many open root and without backing pastes or gases. They are only used in certain cases where the slag that is left from the root reinforcement won't be a problem or where it can be cleaned from the inside before being put into service. Many of the papermills in my area have a considerable amount of piping that is welded this way. There are sometimes consumable rings involved with the SS process, but likely not in many instances and certainly very job specific. Very high likelihood of using backing gas on a lot of tig root applications and depending upon the WPS's involved, maintained throughout the weldout whether that be all GTAW or involve a combination of both GTAW and SMAW. Seeing more application of GMAW/GMAW-P on SS pipe also, as well, some SS FCAW in combination with GTAW roots.
     Aimed towards Sour Dough, basically trying to say that there are a number of different combinations and possibilities that you can come up against so try to figure out your area of interest and work on understanding and perfecting the necessary processes. Best regards, Allan
Parent - - By Superflux (****) Date 05-11-2008 05:06
sourdough,
On SS open root tig when closing up the last quarter on small bore ( or when  ever closing up the final part of the root), make sure you vent the purge (SS steel wool makes an excelent purge dam) and or back off the purge flow. If not, the build up of pressure can cause suck back (insuficient penetration) at the tie-in. Also (for me any way) SS SMAW is one slag trapping sun of gun. I hate SS stick in any V groove. If you've tigged on C/S, just realise that SS is a little "runnier or wetter" and you'll do just fine...
Good luck to ya
Parent - - By Tommyjoking (****) Date 05-11-2008 05:21 Edited 05-11-2008 05:33
SD   as much rod as you have burned I seriously doubt you will have any real issues.   How good are your tig skills...on a big pipe could you walk the cup on that root pass?   That would be all I would worry with is the tig roots and remembering to purge where applicable.  Any job I ever done SS pipe on was 1.  Tig root and smaw out.  2.  Tig all the way.  3. Smaw all the way.  Grab some 308 and run some verts with it...more often then not i would imagine 308 and 309 will be your primary rods to deal with on most jobs.   Its a little more liquid then a lo hy weld and amperage needs to be a bit tighter.  But I doubt you will have any probs with it.  Just use that nex gen and keep your hood down and your collar tight when that flux starts popping off.   As far as downhill SS welds with SMAW I have no idea what to tell you as I have never done it.  Go make some rainbows and some $$ bud!

Regards
Tommy 

Oh yea one more thing: when you pick out cup size for a tig root or hot pass....make sure its big enough for you to keep that hot rod end under the gas ALL THE TIME.....I learned that the hard way with about 20 joints to grind out way back in the day.
Parent - By 803056 (*****) Date 05-11-2008 14:10 Edited 05-11-2008 14:16
One note of caution; if you are going to use "steel wool" as a purge dam, make sure you use "stainless steel wool" so you don't leave any "iron" behind when you remove it.

You can usually find a stainless steel scouring pad at the larger grocery stores or you can get stainless steel wool at some marine paint stores. Here's an on-line source: www.briwax-online.com/sswool.html

Best regards - Al
Parent - - By Sourdough (****) Date 05-11-2008 16:01
Very nice fellers..........I thank you!

I have no doubt that I can lick it, although I have never tigged any thing but shop projects. And the stainless that I have the most experience w/ would surely never make me a pro.

Here in a couple months I'm headed off to Kentucky to find some work for my swab unit, and I think I may stick around a bit longer and throw my hood down and just......watch..........

That's the only way it seems that I learn - by watching a pro.
Parent - - By swsweld (****) Date 05-12-2008 02:43
Hello Sourdough. I could Google it but it won't be the same. Could you explain what a swab unit is? Thanks.

Hope I'm not the only one on here that needs an explanation.
Parent - - By Sourdough (****) Date 05-16-2008 00:01
A swab rig goes in and knocks parrafin and such out of an existing well when it doesn't produce any more. The most common problem in these wells is water. Enough water gets in a low yield gas well, and the gas cant come to the surface. We run our tools down the hole and 7 out of ten times can get the hole flowing again.....
Parent - By swsweld (****) Date 05-16-2008 02:06
Thanks for the info. I was hoping that it wasn't an acronym from out west for structural welding and boilers or something like that.
Parent - - By swsweld (****) Date 05-11-2008 15:33
Thanks for the clarification Allan. I, (like Hillary) misspoke. I was under sniper fire. I have pulled K(Kellogg) and EB (Electric Boat?) rings manually and with machines. Also have welded 360 UH/DH using machine processes on Narrow groove and conventional joint configs. and also autogenous welds all 360 UH/DH SS GTAW. I should have said the uphill statement was referring only to the stick rods. I have never welded E316,308,309 DH. But that doesn't mean that they can't be run DH. I am not sure of what Sourdough is looking at as far as SS work with the gas boom. I'm don't know what their procedure's will specify for the SS work. I made the uphill remark because most of the pipeline work is DH.

At the end of the day you can run in any position that the electrode/wire's manufacturer recommends and the qualified WPS states.

More than a decade ago the company I worked for at the time developed a weld head that used Machine GTAW for root/hot then converted to Machine GMAW to fill/cap for inconel open butt pipeline work in Wyoming. I think it was all 360. I wasn't involved in that job so don't have much info. They made an internal purge dam that ran inside the pipe on a carriage and expanded to the ID. It also had a video camera to examine the root ID after welding so as not to waste a RT.
There are tons of typical and non typical applications, processes and combinations out there. I certainly haven't seen or done it all. This is a great place to get information.

PS Allan, Even though I've never welded SS stick downhill I have wanted to throw the can of rods down a hill a few times :)
Parent - - By aevald (*****) Date 05-11-2008 16:08
Hello Tim, appreciate the clarification and additional information, sounds like you've had some of the "fun stuff" too. Sounds like some pretty techy stuff with the internal purge and camera combo, yet I'm certain it was necessary and prevented a lot of issues in the long run. Talk of purge dams, here's one that some might laugh at; "pieces of bread stuffed inside the pipe", once the welding was completed they flushed the pipe with water. I'm not quite sure how that one would ever relate to code work or be included on a WPS, but I've heard of it being done.
     Many years ago I was working alongside some folks from a mechanical company out of Portland, Ore. called Fullman Mechanical, they had 32 orbital welding heads on the job, it was for SEH America, a silicon chip grower and processor. A ton of small bore SS pipe and tubing, as their process utilized a lot of Argon and Hydrogen. Never quite saw how they went about setting up dams, I believe they may have just done complete purges of all the sections. I was working structural at the time, did the steel for a clean room, the building was approximately 200' x 600' and 65' tall. When it was completed they would cycle the air 6 times per hour, quite an interesting set-up. They also claimed it was better than a surgical room for cleanliness.
      If you ever get a chance get a hold of some of the vertical-down specific SS rods and give them a run. Avesta, Lincoln, and others do make some pretty decent ones, but they, like anything else, definitely take some getting used to. Best regards, Allan
Parent - - By swsweld (****) Date 05-12-2008 03:21
I wonder who first tried the bread purge dam? Does the WPS specify white or wheat or both?
One of the worst smells on a construction job is the purge dam on fire before you finish the root pass.
One of the worst sounds at a nuclear plant overseas was when we were pulling a root pass w/machine gtaw and the plant workers (that didn't inform us) slammed a valve upstream and blew our dam out. Sometimes dam is a four letter word. I bet the dam stories could go on and on.

The eight most dreaded words a welder ever heard "Good as you are, you can handle it" said his fitter.

I do miss the technical side that I use to do but am grateful to be able to make a living at home.
Thanks for the tip on the DH SS rods I will try that out soon.
Parent - - By DaveBoyer (*****) Date 05-12-2008 04:14
I have heard of the bread trick to solder copper water pipe that just won't dry out. Probably the bread purge dam is an offshoot of the plumbing trick.
Parent - By labrandston Date 05-18-2008 15:08 Edited 05-19-2008 01:21
Hey sourdough, I am making this same transition. After what amounts to decades welding with 6010 / 7018 on Iron pipe, I bought my first TIG unit last year and have been specifically focusing on stainless pipe and support members. I wish I had done this years ago because there is a real demand for skilled stainless guys. Here is some of what I have learned. As with any new skill, there will be some investment of time and money involved. I have either bought or been given pieces of stainless pipe and tube to practice on and then done just that.... practiced. I have read every welding forum thread regarding stainless, looked for every book, article or resource on the subject, read it, and then put into practice what I have learned.... everything from equipment variations to reading the colors of the metal. I take my practice pieces to the various welding inspectors I work around, and ask them and other good weld men to critique my work, not just for what is right or OK, but for what if anything, even if it is the tiniest thing, I could be doing better. At this point I could not even speculate on how many hours I have put in, during the afternoon and evening, alone in my garage, but here is the payoff,
The other day I brought some of my 3" shcedule 80, and 2" schedule 40 practice pieces in to a job at one of the plants I do work at, and showed them to the contractor who does a lot of their stainless pipe, the fellow took a hard look at them, and then looked at me and said
"you want a job". That my friend is the highest form of flattery.

By the way, I should have written this above; But this is my first post here on this forum and to give credit where credit is due, This is one of the forums I have been researching in my quest to learn the craft of stainless steel welding, and I would like to thank all the great knowlegeable folks here who have helped me through posting on this as well as the many other variations of welding , materials, and
techincal information.
                                             Regards, Labrandston
Up Topic Welding Industry / Technical Discussions / stainless tips

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