cast iron welding

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new to this site,welded all types of steel many years ago,now work part time at a vintage tractor restoration shophave done a lot of research on welding cast iron tractor parts,best site in my opinion is chucke2009,he tries many approches and they all work as i have noted before...walked into a fab shop today ,which the owner is retiring,and asked him his best approach to welding cast..he has been welding for many years...he uses a mig welder,reverses the polarity and uses 035 flux coated mild steel wire..welds about 1 inch to a v-grooved spot,no pre heat,walks away,comes back and does the same after it cools and repeats until done..welds machinery hubs,wheels,etc,says he has never had a comeback or complaintanyone tried this or any thoughts? thanks
Reply:my thoughts are depending on which type of cast iron it is you may get away with that once in a while if the part isn't stressed after welding but not every time unless he's mistaken cast steel for iron.i.u.o.e. # 15queens, ny and sunny fla
Reply:I wouldn't put any faith in cast iron welded like that. For one thing, you shouldn't "V" groove cast iron, it should be "U" grooved. Also once it gets hot then it should stay hot. Weld an inch, peen, weld an inch, peen on and on. On dirty cast iron there is almost always some impurities that come out and cause pin holes in the first pass. You need to grind almost all the first pass out and weld it again, inch and peen at a time.I have welded a lot and I mean a lot of cast iron and this is the best way I know to get full strength welds with it. I won't do it any other way.
Reply:That sounds odd to me, I would not do anything the way he is doing that with flux core. I would pre heat. I would prefer stick to flux core. On some cast I would use nickel rod, others I would use low hydrogen. If the cast will cut with a torch it is cast steel and will weld good with 7018. If a torch won't cut it clean I would say its cast iron and use nickel rod. If it is cast iron that seems to crack with nickel rod I would try brazing it with bronze rod. I can't say that flux core won't work but it has always seemed to me to have a lot less elasticity than low hydrogen. I would not even try it on cast. Maybe I should. I am interested to hear what others have to say about flux core on cast.The worst thing I can think of happening is if everything I ever welded instantly became UNWELDED
Reply:I have welded cast iron off and on throughout the years. I honestly don't see how his welds don't jump off the iron and run away doing it like that. I always always always preheat before I weld (usually with nickel rod and a buzz box, but have tig'd it also) then I set there like a stool pigeon pecking at it with a peen hammer till it's cool, without "relaxing" the weld you end up with a bead that is loaded with stress and brittle..Just what I've always done but to each his own!Real welders know how to penetrate!(Equipment)Whatever can be used to beat my opponent into submission!
Reply:Maybe castweld will travel across this thread & chime in. I generaly do what I can get away with including borewelding with mig s-3 filler & putting the part in a heat treat furnace. Ni-rod works OK for thin sections if you get a uniform heat soak over the part. Really thick sections can sometimes be done with almost anything if they are not in tension.Now for tractor restoration many who know what they want are going to ask for cast iron filler & it's best done by gas welding. I still have maybe 30-50lbs of welco Kastweld 111, but Lincoln bought Harris-Welco a few years back and dumped the product... It's my understanding that Aufhauser is supplying a similar chemistry rod for the valve seat folks and such. They are at -> http://www.brazing.com/products/Weld_Maint_Alloys/The last welco I bought was 5 bucks a pound 20 plus years ago so it's a good bet it's a lot higher (was fixing some pump impellers). If it's a small crack in a manifold or such a bunch of used piston rings will do the job.Good luckMatt
Reply:I'ma cleanin', blastin', heatin', brazin' fool. When a piece of cast anything shows up I head straight to my O/A torches.2 hours prep,. 5 minutes work.I haven't had a failure in 30 years.Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:HiWhen You talk about pre heat  How hot do you make it?Do you go by how red it gets or do you use a Temp StickDo you use the same procedure if your welding Cast Iron to mild steel?MikeLast edited by newtowelding; 08-14-2014 at 09:33 AM.Reason: added a another question
Reply:I have good luck when I take cast up to about 400f before I weld. Your weld will help maintain heat in the piece while you are welding, but if it cools off too fast after welding it can become brittle. I let it cool off as slowly as possible. Also you must tap the cast part lightly off and on for a few minutes when cooling off, this "relieves" the weld making it less brittle.Yes you also preheat when welding cast iron to different materials.Prep work is literally 90% of the job on cast so make sure it's super clean and well prepped!Real welders know how to penetrate!(Equipment)Whatever can be used to beat my opponent into submission!
Reply:thanksMike
Reply:Question is too open ended to give decent answer. Yes you can weld a cast iron finial onto a steel fence with flux core, 7018, ect.  But tap it with a hammer and the weld is so hard and brittle it will break off.  So yes many people do that type of weld and have success especially if the part never gets stressed. As Matt said above, a lot of bore welding is done mig on cast iron but usually its done on very thick sections. If you magnaflux or die penetrant test one of these cast iron mig welds there are surface cracks everywhere but usually a bushing will be installed into bore and the surface cracking will pose no problems. I have subarced cast iron crankshafts both grey iron and nodular iron and they usually hold up even though the surface is cracked because of the thick sections. There are other methods to weld cast iron without flaws but flux core isn't one. Are flaws in the weld acceptable?Some consider a successful weld one that sticks two parts together, the customer pays for it, and they never see it again. So yes you can weld cast iron with flux core wire and no you can't! PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Hey, good to hear from you Peter! I don't get to post as often & it has nothing to do with WW, just the way things go.I also didn't know how to answer & didn't talk about the cored wire mig 'cause I've never done it. Prolly the OP could be more specific because different problems can use different recipies. To me the big deal about cast stuck to something else is it shrinks & grows different and if it's stuck with, or to, steel it's weaker up to a certain temp and the cast fails, above that it's stronger and causes the steel to upset when it can't grow anymore against the cast... When the whole she-bang cools the cast goes back to where it likes to be and the upset steel keeps on shrinking and pulls away, or on an OD the steel pulls itself apart... Tricky deal for sure!To zero in on the part time "vintage tractor restoration thing" the OP mentioned, I did want to stress that cast to cast is the gold standard (to me) if you can.Matt
Reply:Yes Matt I agree that cast to cast is the Gold Standard. There is so much misinformation on cast welding. Every time another- I weld cast iron with mig-7018-ect all the time and I never had a failure or come back- thread pops up I feel for the newbs. Dealing with cast iron more often than most, a blanket statement like that erks me. A pic or description of exactly what is being welded, intended use after welding, and description of acceptable weld is needed to give a decent answer. An acceptable weld on a decorative item is different on a part that sees stress, or wide temperature swings.I use Lincoln cast iron steel stick rod to weld cast iron exhaust manifolds to jigs so I can resurface them in a mill. Works great. Most have been cracked and welded, but on the cracks I spray weld with nickel powder or stick with high ni rod. The steel rod is good enough to hold to jig but not to weld cracked areas that will see temp swings, the hard brittle welds would quickly fail.Happy WeldingPeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:I agree with the spray weld with nickel powder. At this point most people say "Huh" But its the best I have found for cast repairs.  For parts too large to spray I often OA Braze.  When using nickel arc its best if the part is VERY Hot. Like RED hot when being welded and then allowed to cool SLOWLY in wood ashes, vermiculite etc.Lincolin Power Wave 450, Lincoln Powermig 255, Lincoln Pro Mig 140, Lincoln Squarewave Tig 275, Miller Big 40 G(with Hobart Hefty suitcase), Thermal Arc 95S and Esab PCM875 in an already full machine shop.
Reply:Originally Posted by lowrider85..................................................  ..............,says he has never had a comeback or complaintanyone tried this or any thoughts? thanks
Reply:Dittos SandySent from my C771 using Tapatalk 230+ yrs Army Infantry & Field Artillery, 25 yrs agoMiller 350LX Tig Runner TA 210, spool gunLincoln 250/250 IdealArcESAB PCM 500i PlasmaKazoo 30"  vert BSKazoo 9x16 horiz BSClausing 12x24 lathe20T Air Press
Reply:Originally Posted by BobI wouldn't put any faith in cast iron welded like that. For one thing, you shouldn't "V" groove cast iron, it should be "U" grooved. Also once it gets hot then it should stay hot. Weld an inch, peen, weld an inch, peen on and on. On dirty cast iron there is almost always some impurities that come out and cause pin holes in the first pass. You need to grind almost all the first pass out and weld it again, inch and peen at a time.I have welded a lot and I mean a lot of cast iron and this is the best way I know to get full strength welds with it. I won't do it any other way.
Reply:Originally Posted by BobI wouldn't put any faith in cast iron welded like that. For one thing, you shouldn't "V" groove cast iron, it should be "U" grooved. Also once it gets hot then it should stay hot. Weld an inch, peen, weld an inch, peen on and on. On dirty cast iron there is almost always some impurities that come out and cause pin holes in the first pass. You need to grind almost all the first pass out and weld it again, inch and peen at a time.I have welded a lot and I mean a lot of cast iron and this is the best way I know to get full strength welds with it. I won't do it any other way.
Reply:thanks nbs,can you test cast v/s steel with grinder spark test,so that some where..hit welding bench steel,sparks a lot different than grinding cast ironwill try the torch cut test on some discarded tractor parts..all tractors we restore are from 1920 s and 1930 s
Reply:I find this thread interesting as I have virtually no experience repairing cast iron but one:My 1964 Mack had the turbocharger mounting foot break off the manifold with the prior owner. Seems he neglected to replace the upper brace to the housing for support some time prior to the breakage. Basically he gave me the great running tractor as it was way beyond worn out for road use anyway. I decided to attempt a repair at this mount so started asking questions at both the welding store, and a local welder whom taught welding at the community college also. The main suggestions were to get the manifold as clean as humanly possible, deep groove with a rounded bottom, preheat to about 450 degrees, get on it with ni rod, and cool as slowly as possible while peening occasionally through cooling. Taking these suggestions to probably the extreme, I had a buddy steel shot blast the manifold after degreasing in my caustic soda aqueous parts washer, then washed it again, clamped the partial boss back onto the manifold, ground a good groove into the fracture line of the part(s), used a 500 degree marking pen to gauge temp and using a rosebud got it hot. When close to temp the torch was pulled away, a weld made all the way around the parting line, and a 300 degree marking pen was used to maintain warmth for the next three to four minutes while tapping with a small ball peen hammer. This was done in the summer of 2006 so it's been a while and the repair has held up. I just had the hood open today and looked at it with nothing out of ordinary noticed. I know the repair worked and am not bragging on it at all but rather asking if what I did was right, or just got lucky? That turbocharger is physically heavy, and the engine has quite a bit of vibration just being a diesel so I'm wondering if the operations I followed would work in other applications?Thanks,SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:SlobIts hard to argue with success. Edges an corners are easier to weld than the center of a section. I probably would have tried a cold weld first and switched to a preheat if there were cracking issues. An edge needs no preheat at all. I find when heat is needed, if there are cracking issues, a minimum of 600 and up to 800 degrees is needed. On really thick sections even more heat may be needed. If your repair has been in service for 8 years I consider it a successful repair for sure! Welding cast iron can be tricky, two like jobs will sometimes weld differently, one requiring a higher preheat and postheat to prevent cracking.PeterEquipment:2  old paws2  eyes (that don't look so good)1  bad back
Reply:Originally Posted by castweldSlobIts hard to argue with success. Edges an corners are easier to weld than the center of a section. I probably would have tried a cold weld first and switched to a preheat if there were cracking issues. An edge needs no preheat at all. I find when heat is needed, if there are cracking issues, a minimum of 600 and up to 800 degrees is needed. On really thick sections even more heat may be needed. If your repair has been in service for 8 years I consider it a successful repair for sure! Welding cast iron can be tricky, two like jobs will sometimes weld differently, one requiring a higher preheat and postheat to prevent cracking.Peter