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Up Topic Welding Industry / General Welding Discussion / Bad weld t's
- - By Sourdough (****) Date 08-03-2007 02:51 Edited 08-03-2007 02:53
Got a batch of sch 80 x 2" weld t's that have me tearing my hair out. Irradic arc, sticking to one side gouging, blowouts, the works. Tried everything to stay consistent, but ended up with a grinder in my hand half the day....I'm pissed! The rest of the day I was merrily sparking away on 20' joints of the same schedule pipe.

Can anyone shed a light on what kind of manufacturing procedure could cause this in prefabbed parts? Are they just junk/defective??

It's the same brand I've been using for three years, but is the only batch I have had with this problem.......
Parent - - By CWI555 (*****) Date 08-03-2007 03:18 Edited 08-03-2007 03:32
Strong possibility for magnetic arc blow, your description fits it nearly perfectly. The pieces could have been lifted by a magnet or some other fashion been magnetized leaving excessive residual magnetism polorized in a specific direction. Can't say as I've ever seen it in that size pipe though.
http://archive.metalformingmagazine.com/2001/05/Lincoln.pdf
Parent - By reddoggoose (**) Date 08-03-2007 13:06
I'm with CWI55. Makes me think of residual magnetism. I've talked with pipeline inspectors that have ran into this on line pipe that has been fit up on the right of way, but won't weld. I've seen pictures where the pipe was so magnetized that a 10# hammer would stick to the side of the pipe. Had something to due with the way the corrosion resistant coating was put on, but I've never heard of that problem on small pipe. CWI555 is probably on to something with a magnet maybe being used to lift and move the pipe.
Parent - - By dbigkahunna (****) Date 08-03-2007 22:22
Dough,
What is the country of origin? If they are from India you have a 50/50 chance of getting good/bad. I had a bunch of 8 inch standard wall tees and flanges that were harder than Chinese arithmetic two years ago. Carbon on them turned out to be 0.45%. They were not even weldable. Supplier made good on them but the company I worked for had to eat the fabrication charges as we furnished. I have not had any problems with USA or Korea materials. Ask the supplier for the MTR's on them. If it is not stamped on them country of origin, and the MTR's do not state country, suspect XXXstan.
BABRT's
Parent - By darren (***) Date 08-03-2007 22:56
sprinkle some grinder filings on them and see how much sticks and how far they whisker. it will at least tell you whether they are magnetized or not. just dont use the filings from your day of grinding on the same material cause if it is even a little magnetic it will be very magnetic when ground into powder.
darren
Parent - By CWI555 (*****) Date 08-04-2007 00:22
babrt,

possibility of this, but the arc description doesn't fit. In saying that, I've seen A572 plate out of the Ukraine come off the ship with in excess of 50 gauss in it. So it could be a combination of errors.
Parent - By Sourdough (****) Date 08-04-2007 14:29
Korea.

Testing for a 30" line on Monday....they need a couple more hands....?

(Douglas Pass, Co)
Parent - - By downhandonly (***) Date 08-04-2007 00:59
try beading them on dc straight and see what happens, I've tried that tieing into old magnetized line pipe and it seems to help.
Parent - - By 803056 (*****) Date 08-04-2007 04:07
Try to demag the pipe.

You can wrap several turns of welding lead around the pipe and "zap it" with AC current. You can use any AC welding machine to energize the welding leads. You then reduce the current and re-enegize the welding lead. Repeat the steps several times, reducing the current each time. The time for each "zap" is only a couple of seconds, so shorting the  welding leads shouldn't hurt the welding machine. I usually have one lead connected to  "stinger" with any electrode and the work lead that is wrapped around the pipe is connected to the welder and to a small plate. Simply strike an arc against the plate to complete the circuit.

Once you have reduced the current to the minimum setting on the welding machine, remove the wraps around the pipe one loop at  time. Each time you remove a loop (or turn), restrike the arc momentatily, and remove another loop until you have no loops left (remember to strike the arc each time you remove a loop).

Once all the cable has been removed, the pipe should be demagnetized.  A more effective method is to move the loops of welding lead along the pipe from one end of the pipe to the other while the welding arc is "on". This means you will need  helper.

You have to use AC for the method I just described!!!!!!

Best regards - Al
Parent - - By NDTIII (***) Date 08-04-2007 10:37
Another thing you can do is while you are welding on the magnetized pipe, use another welding machine and wrap a coil around the pipe and run AC current through it while you are welding. This will neutralize the magnetic field in the pipe until you are finsihed welding. I have seen this on pipelines in the past and that ishow we handled it.
Parent - - By Sourdough (****) Date 08-04-2007 14:25
I don't have time for any of that. I have to be done on these hook ups in three days. I shouldn't have to put up with magnatized 2" fittings.

The supplier needs to eat it......
Parent - - By CWI555 (*****) Date 08-04-2007 16:55
Assuming it is magnetic arc blow, there isn't much you can do other than de mag it with one of the varying methods others have posted here. It is easily and rapidly detectable for future reference with a gauss meter. The problem your going to have now is, the supplier can claim ignorance, and blame you as you've already been welding on them and therefore have created a condition that could magnatize it. That was the same problem I ran into on the 572. Unfortunetly for them our team spotted particles standing on end, and they were checked before they came off the ship. The shipping company ended up eating the cost of demaging and delay.
Parent - - By dbigkahunna (****) Date 08-05-2007 01:40
IF you can get away with it. Tack up. Take your rosebud and get the weld grove and adjacent pipe up over 400 degrees. Use a temp stick so you dont get the fitting too hot. If you have an inspector, send him out for doughnuts when you do this. Be sure it is the fitting and not the pipe that is magnitized. I have done this trick on tubing anf fittings . About 75/25 success. If it is the fittings the supplier better make them good. If you have time get another brand of fitting and see if you have the same poblem.
Good luck
BABRT's
Parent - - By CWI555 (*****) Date 08-05-2007 18:16 Edited 08-05-2007 18:22
Very good point. Enough heat will kill it for the most part. However; reaching the curie temperature would likely be necessary, so that has to be balanced against potential gains and losses in material characteristics.
Parent - - By Sourdough (****) Date 08-06-2007 02:47
So there you are, stinger in hand, deadline to meet and Questar, Williams , and B&S oilfield service counting on you to continue being the welding stud that you are. You get bad fittings......crap! Do you:

A: stop sparking and arcing, demag every one of the 20+ fittings that are magnetized.

B: throw a fit and demand that the entire 4 million dollar operation cease until you can get another box of fittings.

                                                                         OR
C: Git er done, grinding out the bad spots and making sure everything is to code as it can possibly be, assuring that every one who thought you were a welding stud still sees you that way. Oh, and you get a check for a little over 5 grand....................
Parent - By 803056 (*****) Date 08-06-2007 03:45
So, why did you ask?

Go get em tiger!

Best regards - Al
Parent - - By DaveBoyer (*****) Date 08-06-2007 04:06
If You HAD a demagnatizer on Your truck, You could De Mag the whole box in 5 minutes. How long does it take to do the repair work?
Parent - By 803056 (*****) Date 08-06-2007 05:10
Hello Dave;

Good point, but you don't need a special demag. machine. Its simply a tool every welder could use if they knew how to do it. There is a way to demag with DC, but not every welder needs to know how to do it as long as sparks fly and a grinder is handy. No need to work smart, just arc, spark, and sweat.

Besides, its a secret that's best kept a secret. It keeps a few of us gainfully employed. We shouldn't let everyone know about a better method of working. ;<)

As my good friend Rick says, "You can lead a horse to water, but you can't make it wear a bikini!"

Best regards - Al
Parent - By Tommyjoking (****) Date 08-06-2007 05:41
SD

If I was having that much issue running a good weld on these fittings....you bet stop it all untill you get what you need....at least in that case it makes a good explanation of how serious it is to demag the fittings (if thats the problem) and justify the xtra time spent or stoppage for replacement.  If your supplier screwed you with cheesy (&(*&U   out of country crap then at least you are letting you customer know you will only do quality work....they will respect that every single time .... time limits or not.   Like a former boss use to say  you can sell high quality at almost any terms and price you want....but you cant give away sh85t no matter how hard you try.

I wish you luck man
Tommy
Parent - By CWI555 (*****) Date 08-06-2007 13:11 Edited 08-06-2007 13:14
NDTIII has given you a valid method of mitigating the problem while still producing. So I'd say C. git er done utilizing NDTIII's method of mitigation. That is assuming no other equipment is available to demag it. Thats all assuming it is magnetized. based on your description I give it 90 percent probability.
Parent - - By Tommyjoking (****) Date 08-06-2007 05:29
Nice Al

thats a good trick that most would not know   really just letting the parts soak with any ac current surrounding them will do the trick ...high amperages will do it the fastest......but just an extension cord on 110 running your freezer  wrapped tightly around a box of fittings should do the job overnight unless these things are so magnetic they will pick up half a small box of eight penny nails or somthing.  

If thats the problem then that supplier owes for down time as well as replacement. 
Parent - - By 803056 (*****) Date 08-06-2007 05:58
I've never tried using an extension cord, but I will give it a try. I never say it will not work until I give it a go!

I was taught that you needed to induce a magnetic field greater than the existing remnant field. That can be accomplished with higher current or more "turns" of the cable, so your solution to the problem sounds plausible.  Another one for the "Myth Busters"!

What I didn't say was that it may be necessary to perform two demags to ensure mitigation of both the circular and longitudinal residual fields (both can not coexist, but you may not recognize the circular field, so assume it may be present). The longitudinal field is the predominant residual field most welders notice and it may be induced if the pipe is transported in the north-south direction or stacked in the north-south direction in the northern latitudes (it gets worse the closer you are to the North or South Poles). Always demag the longitudinal field as the last step using the loops around the pipe or other work piece.

The biggest piece I've used this method on was a 24-ton beam. It took all of 20 minutes to set up and complete. It's a nice day's pay, no sweating and that new customer has been with me nearly twenty years.

But, again, don't tell anyone. It's our money making secret!

Best regards - Al
Parent - - By ssbn727 (*****) Date 08-06-2007 19:48
Hey Al!

ROTFLMAO!!!!
Why do'nt you post it in the "Tricks of the Trade" section of the forum. :)

Respectfully,
Henry
Parent - - By 803056 (*****) Date 08-07-2007 20:41
Then everyone would know.

I told you, it's our secret! Besides, everyone that reads the "tricks of the trade" reads all the threads s well. They do, right?;)

Al
Parent - - By ssbn727 (*****) Date 08-08-2007 00:41
C'mon Al!!!! I thought you were an educator :) Since you were the one who first mentioned it, I figured you be the one to publish it, and get acknowledged for doing so :)

Play it Foward :) :) :)

Respectfully,
Henry
Parent - - By 803056 (*****) Date 08-08-2007 03:22
Thanks Henry.

I don't believe there is an original thought in my head. Everything I 've learned is because someone else did the leg work and passed the information on to me and others like me that were willing to ask questions and listen to the answers offered.

If you believe anything you heard from me has value, you need to pass it along to someone else that can put it to good use. If that means printing it in another forum, then by all means feel free to pass it on. :)

Best regards - Al
Parent - By ssbn727 (*****) Date 08-08-2007 03:38 Edited 08-08-2007 04:49
Talk about delegating :)
Nah Al  - you can do it!!!
Respectfully,
Henry
Parent - - By CWI555 (*****) Date 08-06-2007 13:17
Will have to file that one away Al. That sounds like it should work. Learn something new every day.
Parent - - By Sourdough (****) Date 08-07-2007 00:23
I figured out why I couldn't get my arc right........my lug nuts were loose on my rig.........
Parent - By ssbn727 (*****) Date 08-07-2007 01:12
Hi Sourdough!

Go figure huh???
Nine out of ten times, it's the most obvious of reasons that are right in front of us (literally speaking of course)wherein lies the solution to our problems!!!

I know that I've been there too many times to understand how you feel about finding out that the solution was right in front of you!!! I'd be a rich man nowadays if I could get a dollar for every time I was confronted with such conundrums. :)

Well I'm glad that you figured it out... All the best to ya :) :) :)

Respectfully,
Henry
Parent - - By CWI555 (*****) Date 08-07-2007 01:33
That would do it to
Parent - - By DaveBoyer (*****) Date 08-07-2007 01:59
Now that the problem has been resolved, if We are still on the magnetism thread here are a few more thoughts:
  A thin steel scale or a hacksaw blade that isn't already magnetized is a handy indicator for checking for magnetism, it isn't as sensitive as a goss meter, but it works if the parts are magnetized with much strength. Touch it to the work, and observe the feeling/behavior of the scale or blade as You pull it away. Try on several places of the part, the orientation of the poles could be in any direction.

  A demagnetizer is just a coil of wire energised with AC. The part should be moved around within and passed through the coil. If the flat type, the part needs to be moved around above the plate. The coils remains energized untill the part is outside the magnetic field, Don't turn it off while the part is in the field. Remove Your watch if You wear one first.
  I am not sure the extension cord will give results, as the 2 conductors will have fields thet tend to cancel each other.
  The welding cable wrapped around the part and hoked to an AC machine is exactly what You need, and it will not take much amperage. I think a Buzz Box set on moderatly low amperage, like the pipe thawing setting or less would be fine, be carefull about exceding duty cycle on a dead short.
Parent - - By CWI555 (*****) Date 08-07-2007 02:07
magnatizing theory was based on the assumption everything else was in order. It was worth the thread to see the alternate methods for dealing with it. To me a guass meter is the best route, followed by shavings or mag powder, or a thin ferromagnetic piece of steel.
Parent - - By Sourdough (****) Date 08-07-2007 16:51
The next hook up is in a week. I've already called the supplier and told them to fix it. They promissed from now on they are going to test them before they go on the shelves.......
Parent - - By ssbn727 (*****) Date 08-08-2007 04:47
Hey Sourdough!

Did'nt you just tell us that the problem was with the loose lugs on your welder?
Or is it the loose lugs in your head lately??? I mean what did the supplier do wrong if the problem stems from the power source connections??? Am I missing something or are my lugs loose??? :) :) :)
Btw, I do'nt think so, and neither do the headshrinkers - he he he :) They say that I'm just little bit irritable - IMPOSSIBLE!!! (how's that for denial :)) because, of this latest round of chemo I'm on - go figure!!! What me worry??? They're just balancing the matrix in my system which is a very complex one these days!!! Ohh how I wish for the days of simplicity :)

Respectfully,
Henry
Parent - By Sourdough (****) Date 08-09-2007 20:46
You'll be fine I reckon....too damn ornery to die, anyway!

Aint life a bitch?...............
Parent - - By billvanderhoof (****) Date 08-10-2007 05:00
Be well Henry,  while praying for Chuck I guess we'll just have to throw your name in there too.
Bill
Parent - - By ssbn727 (*****) Date 08-10-2007 05:27 Edited 08-10-2007 05:37
Thanks Bill!

Every little bit helps and coming from you, I especially appreciate it!!!

Btw, this is just another "maintanence" round so to speak so, I'll be allright!!!

Sourdough just reminded me about how I got through all of the other times of crisis in my life; Way back in 1979, I fell down a missile tube hwile helping to build one of the Trident submarines (You guessed it SSBN727!!) and all that happened to me was that I broke my "Humorous" - yeah right!!!, bone... Five punks tried to kill me back in 1986 coming out of the subway station in NYC, and they could'nt do it... In 1997 hangin on to dear life, I recieved the Gift of Life (Liver Transplant) and it's going to be TEN YEARS this October with no complications so far!!! In 2004 I was diagnosed with osteoporosis, osteonecrosis & osteoarthritis - all as a result of having non-Hodgkin's lymphoma which was caught in it's really early stage which is very fortunate for me so, I guess if it was'nt for bad luck, I would'nt have any luck at all!!! :) :) :)

Btw, they opened up my right hip area and scraped the crap out of the joint also!!! By now, almost none of the blood that circulates in my blood vessels originated from my own original blood so who knows what Race/ethnicity I have flowing in me veins - Ha Ha Ha!!! :)

The way I look at life these days Bill is simple: If I'm gonna go -then I'm gonna go when it's time to go!!!

But, I'm not ready to go YET!!! Not by a long shot!!! Besides, the Big one upstairs apparently still has plans for me even though I'm clueless as to what they are yet, maybe it's better that way :)

Am I scared about this latest illness if you want to call it that because, I call it a nuisance??? I'd be lying to you if I said I was'nt but, after all I've been through, there's a whole lot more faith taking up more space in me head & spirit than there is fear, and that you can take to the bank my Friend!!!

Anywho, Thank you Bill & Sourdough for your prayers :)

Let's all pray for the Families of those trapped Miners in Utah, and for the souls of those miners as well!
May God Bless Them in this time of crisis :) ;) :)

Respectfully,
Henry
Parent - - By DaveBoyer (*****) Date 08-11-2007 02:26
Henery, I wish You the best of luck staying ont op of all that. I joke with the nurses & Dr.s that "aside from the cancer I am in perfect health". What that really comes from is seeing some of the older folks when I go for treatments that have a whole lot of really serious illnesses, I figure I am luckey to be dealing with only one.
Parent - By JA (**) Date 08-11-2007 03:03
join the Ironworkers Union..........
Parent - - By 803056 (*****) Date 08-11-2007 12:29
I'm sorry to hear that so many of our regulars are having health problems. It seems that we're reading about health problems more and more. Is it that we're all getting old? It's amazing how many of us wouldn't be here if we experienced the same health problems just a few years ago. Broken bones, cancers, arthritis, heart ailments, and the list goes on. 

Chuck, Dave, Henry, I'm sorry to hear of your problems. Take care of yourself and know that we're all pulling for you.

Henry, I agree with you, when it's your time, it's your time. The man upstairs has a plan and when he calls, we all answer.

If we're still here, it's for a reason. Maybe it's so we can do a mind dump and pass on what we've learned to the younger men and women before we do take that last long walk.

Best regards - Al
Parent - - By Stephan (***) Date 08-12-2007 11:37
Al,

would you allow to use your words for conveying those three Gentlemen you have named in your post my very very best wishes?

It is hard to reading bad news and twice as hard when those news pertain great human beings.

Chuck, Dave and Henry, I will keep you in my prayers!

May God bless you...

Thanks Al and all the best,
Stephan
Parent - By pipefitter100 (*) Date 09-24-2007 00:59
try heating it over 450 not 400 and also try wrapping your ground around the pipe about 6 times
Up Topic Welding Industry / General Welding Discussion / Bad weld t's

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