Welding cast iron to steel

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I have to weld a 10" steel elbow to an old cast iron tee in an 80-year old steam heat system.  Was thinking of using 55 or 99 ni rod, but have never done the CI to steel before.  The CI tee is massive, we tried to tac them with 6010 but they would not bond.  Any ideas or suggestions?
Reply:Nickle rod works.  I always do short beads with a fairly high amperage arc, trying to keep the heat from building up in the cast iron.  I have no idea if that is the recommended way to do it, but it has always worked for me, even on highly stressed parts.Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:all state super 4-60 is specked for welding cast to steel but it is a flat classified rod.  Not sure how it is going to work out of position.      Is tig welding it possible?  You could use 4-60 T  which is just the same filler but for use as a TIG rod.  TIG welding cast gives you great control in all positions and is how I do most of my in shop repairs of cast materials.www.burdettenetworks.com
Reply:curious how the tee was originally welded..?
Reply:This is not a good idea plus not legal by the boiler codes in our state. (KY) If you could make it seal the different thermal expanison of the tee & 90 will make it crack.
Reply:I agree that it won't be code compliant. I would wager that the original cast pieces are flanged into the system. If so, you should be able to transition to the steel with flanges. However, most welding rod that will weld cast iron can also be used to weld cast to steel. Ni-rod 55 or 99 is probably a good choice.
Reply:This is not recomended but if you have no choice I would use a hermetrically heated ENiFe55 or 99 small rods very short welds 1-2" long and ping lightly with a ball ping hammer not too hard if it were me I would wrap the weld with a welding blanket and seal with a welding compound such as Scotch Weld. I would continue this process until i get all the way around then go back and repeat the process until completely finished, oh i forgot each time you wrap with the blanket you have to let it cool to touch .It will take a good while to do this but I have found this to work for [email protected]
Reply:We have no choice but to weld it out.  The tee is a screw tee, and the contractor has us welding the new elbow onto the tee at the end where a plug used to be.  We don't like it, but it was not our choice.  So we are looking for suggestions and ideas. Attached Images
Reply:That would have been great.  We inherited this job, and that plug did not want to come out.  It was sprayed (pipe buster), heated, wrenched (4' wrench with 8' cheater), even tried putting a come-along on the cheater as tight as possible then heated with cutting torch--nada, did not budge.  So we sliced it with the grinder and used a lump hammer to take it apart.  Even that was a fight!  After all was said and done, the "ring" inside this 1928 plug which holds the threads would not shake lose.  So, we were told to weld the new elbow to the CI tee. Attached Images
Reply:bust out the rest of that plug and run a weld all around the stub "ring" , whatever that has the threads that are left.  that will shrink up the little bit of threads. should unscew pretty easy after that
Reply:Thanks, we may have to try that idea.  We have already busted out the face of the plug, all but that damn ring of threads.  I've cut through it in several places, but it won't budge.   I don't have a picture of it with the rest removed, although the only remaing part of the plug is the threaded ring and the thick casting that surrounds it. Attached Images
Reply:I cut out threaded pipe and plugs all the time, cut through the ring, try not to damage threads in tee, just take a 1 inch piece out, heat and try cold chisle to break out chunck and then the rest of ring should peel out with out too much trouble, usually those plugs are cast and you can crack out a small chunck , once the chunck is out the ring will release from the fitting
Reply:I would put a nipple in there and weld your new pipe to that.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:I tried to weld a CI fitting in a pinch and it sucks, 309ss kinda worked, only a pinhole leak. Just dont do it, especially if it is steam.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:That's what I thought before beginning the nasty battle.  Then, in hindsight, I was wondering how I'd manage to tighten a small 10" piece of pipe up there amongst the smaller pipe galleries and ductwork.  Though it sure would've been nice welding pipe to pipe.  It hada been a funny sight watching 2 grown, 200-something pound men getting their asses beaten by an 80-year old ci tee.
Reply:If that is old enough, there might be some kind of sealer like litharge and glycerin in the threads. I would take Roadkillbobb's advice and heat the inside pieces well and knock them free with a good chisel. Maybe use a die grinder and carbide bit to put a deeper groove down near the threads to give more room so the piece you hit can move inward easier.Do you have an OA torch handy for the heating? Guess you could lay a large bead on the inside of one piece to heat it, if not. When the bead shrinks, that might even help pull the piece away from the threads, although you would want to be ready to hit it while it's still very hot, before it shrinks much, I'd think.
Reply:Jimmy,Please keep the pictures coming.  I know nothing about steam fitting and this is seriously interesting.ThanksCon Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Why don't you replace the tee and the branch 45 with new weld fittings?
Reply:Originally Posted by davinwheelWhy don't you replace the tee and the branch 45 with new weld fittings?
Reply:from the pictures it looks real tight down there, might not be enough room to start removing those big fittings. even though its easier to split a fitting off the pipe to get clean threads....hmmm where s the dwaf welding crew.....
Reply:Originally Posted by roadkillbobbfrom the pictures it looks real tight down there, might not be enough room to start removing those big fittings. even though its easier to split a fitting off the pipe to get clean threads....hmmm where s the dwaf welding crew.....
Reply:That's a fairly thick section, but your "all in" now.I'd take a shot at shrinking the inside with a 7018 stringer bead on the inside ring (it'll tink and pink but a lot of it will stick and shrink). When done weld a bar to the inside bead so you can get something on it to turn with.Good luck!Matt
Reply:Originally Posted by Fred sbust out the rest of that plug and run a weld all around the stub "ring" , whatever that has the threads that are left.  that will shrink up the little bit of threads. should unscew pretty easy after that
Reply:Originally Posted by davinwheelEven if you thread a new piece of pipe into the tee you still have to make a weld to the 90 deg elbow. Save time and money by doing a quality job and not trying to cobble something together.
Reply:Another vote for welding a bead on the inside to srink it. If that fails, cut the tee out and get rid of it. The customer might want quick and cheap but the liability going to fall on the last guy to touch it if something fails.Tough as nails and damn near as smartOriginally Posted by roadkillbobbI agree with you 100%, but the $$$ part is up to the customer , and many times they dont see the big picture just a quick cheap get it done attitude..
Reply:Originally Posted by monte433If they won't let you do the job right, walk away because if something goes wrong you will get the blame and legal problems.
Reply:If a 10" steam line comes apart, even if it's low pressure, someone is likely to die...
Reply:Originally Posted by TozziWeldingI would put a nipple in there and weld your new pipe to that. C.
Reply:Originally Posted by Rick VFurther, the very existence of this thread on the WeldingWeb could well be evidence item #1 in any any lawsuit should you weld as per the original concept and something break in future.
Reply:Originally Posted by Rick VNote the flow of the story line...jimmyo, by asking this question you may have limited your options to:a) put a nipple in there and weld your new pipe to that (threading - approved original construction method for cast iron), orb) a) replace the tee and the branch 45 with new weld fittings. . .
Reply:Money is what it's all about.  The company we were hired by bid the job (probably low-balled it) without really doing their homework.  They didn't even know it was a ci tee, didn't even get the size correct on the drawing.  Nonetheless we are now stuck with doing the fixing . . . as usual they don't care what's right, quick, fast and half-assed to make them money.  Just do it!  We would have left the darn tee alone, moved further down the 10" pipe, fish-mouthed the 10" and welded it out.  We'd of been done already.  This tee has added many man hours and now seems as though it may not even work.  Well, you know who gets the dirty end of the stick, right?  The working guys, as usual, if we don't make it happen.  He'd never go for more hours and material having already bid it out.
Reply:The time already spent is water over the dam, now there's no choice but to carry on and follow through. Even if the new plan is to replace the plug and then tap-in elsewhere, the damaged plug has to be removed.The "T" looks very clean inside, the plug will surrender easily once a slice is taken out of it to relieve the concentric pressure. One way would be to use a recip saw to make a couple of relief cuts that reach almost through the threads, then make a "pie"  slice. Knock the pie piece out with a cape chisel. With 10" pipe, there's probably room for a 4" grinder fitted with a slice wheel to do the cutting.Good LuckLast edited by denrep; 05-30-2011 at 10:41 AM.
Reply:I agree with you, but now I have to sell it to my employer to spend a bit more $$.  Not knowing how close he cut his bid, it will prove interesting.  Removing the tee completely suits us best, easier, cleaner more secure.
Reply:It seems we have now come full circle.The job was not bid properly so the contractor would rather do a cobbled up, possible dangerous, installation instead of doing the right thing and finishing the job correctly even if it means he looses some money in the process.I vote for a proper fix regardless the cost and who must pay for it.  Because that will insure he is on the bid list next time and also that will give his company a good reputation, not a bad one that an improper, possibly dangerous, shortcut fix might give.Good luck guys
Reply:If the boss thinks that welding to the CI tee is going to be cheaper, he's mistaken. The cost of the Ni-Rod (waaay expensive), and the labor intensive (forget the unsafe) welding process will far outweigh the cost of removing the tee.
Reply:Absolutely right.  And we will tell him so.  However, he is not from here (USA) and does not see things the same as we do.  We have decided to inform he he needs a new 10" tee regardless of what HE thinks.  Now we shall see what develops.  (They are extremely distrustful,  He may not believe our assessment and bring in someone else.  So be it.)
Reply:Originally Posted by jimmyoAbsolutely right.  And we will tell him so.  However, he is not from here (USA) and does not see things the same as we do.  We have decided to inform he he needs a new 10" tee regardless of what HE thinks.  Now we shall see what develops.  (They are extremely distrustful,  He may not believe our assessment and bring in someone else.  So be it.)
Reply:Another option...cut out the tee and the 45, smash them with a sledge hammer, and let the chips fall where they may...
Reply:Here is the choices I think I would have if I were in your shoes.1.  Flat out refuse to do anything I felt was unsafe for the people that will be exposed to this steam line for its intended years of service and quit if that because necessary.  In other words - if I didn't feel I wanted to do a bad job (IMO) then I wouldn't do it regardless what he threatened.  At that point I wouldn't care much either way what he did.2.  Or do the right thing.  Go to the person thats in charge of this ****ed up steam line 24-7 and explain to him what his contracted dube ( your present boss) is trying to cobble up for him - and why!!!!  Explain that if you were to follow your bosses orders and weld on this TEE it will be ticking time bomb just waiting to kill one of his employees, and why!!!!  Then let him know since you have explained all this to him and he now understands whats going on down there in the tums you can now leave this job for good with a clean heart and mind.  Then do just that!!!!!3.  Tell the man in charge of this plant what I said above and take the rest of this job (and all their future work) away from this dube you're working for now and put his *** out of business.  At least IN THERE!!!!! I like #3 the best so I'd probably do all three of them - and still take his work from him.     After I got done explaining all the messed up work this dube is doing in there all he'll want to know is what he needs to do then, that I'd also explain to him.  He needs to run this guy off and stop paying him for low quality work - and hire me to finish this job the right way - for a low introductory price of - what he is going to get out of not paying this creep.  Then I'd have all his work from then on.Scratch his back and save his *** - and do your part to cover what you said - and he'll scratch yours.  Been there - did it - and it does work just like that - sometimes.   Search your heart.  You'll know whats right for you to do.Good luck manLast edited by slowhand; 06-01-2011 at 08:28 PM.