welding cast iron

[Jerry P.]

I would like to know if it is possible to weld cast iron window sash weights to each other and how to go about doing it?

[JWD]

pardon me but its late and im trying to picture what your asking?:confused: :eek:
does someone else know? sorry

oh and everything is possible! except for me gettin a Dynasty Tiggy! well thats another story;) !

[ROCK]

JHP4SITE.......... ALL OF THE WINDOW SASH WEIGHTS I'VE SEEN ARE LEAD......... BUT I COULD BE WRONG ARE YOU SURE THEY ARE CAST IRON........IF THEY ARE I THINK YOU CAN DO IT WITH A ROD THAT HAS A LOT OF NICHOL IN IT DESIGNED FOR CAST IRON......... LET US KNOW........ROCK...............:cool:
SSCOTT@MILLERWELDS.COM

[Jerry P.]

Am pretty sure what I have is 'gray iron': very pourus. It had been used as window sash weights in double-hung windows installed around 1920. I'd like to be able to weld several of them together to create a 3 dimentional effect. But how?

[ROCK]

JHP4SITE... WELL TRY SOME STICK ELECTRODES WITH A LOT OF NICKEL IN THEM............. MANY COMPANYS MAKE THEM.......... LET US KNOW HOW IT WORKS OUT..............BE SAFE..............ROCK...........:cool:
SSCOTT@MILLERWELDS.COM

[Sean Brown]

My experiance TIG welding Cast Iron is that it doesn't work. If you pre-heat and post-heat the castings well, you may be able to stick them together but the weld will be porous and full of voids (all of mine were). I know a guy who tried to weld a cylinder head using TIG and it turned out like crap too. If you use a stick and pre/post-heat the thing as above, you should be able to make a decent weld providing you use the high nickel rod as ROCK says.

The right way to do it is with a torch and actual cast iron rod (something like Welco Cast-Weld or similar). You have to pre and post heat the crap out of it to keep it from cracking. Usually they post heat over 12 or more hours from 1,200F to make sure all the stresses are relieved.

[HAWK]

Sounds like your sash weights are small. Try using a double v groove joint and a 55% nickel rod. If the puddle spits, bubbles and refuses to take, try 99% nickel rod. With small pieces of cast you may not have to pre or post heat. I have had great success with old singer sewing machine pedals, cast iron skillets, cast steel transmission shifter forks, etc. with 3/32" 55% or 99% nickel rods. I generally burn them on the upper end of the heat range and turn my dig up around 60%. I have also found that 99% nickel rods work well for welding cast iron to ductile iron (strange job for utility contractor). Sometimes if you can get some nickel deposited(even if it porous), just grind out the bad areas and start welding on the good base metal that was deposited. Just experiment. From what I hear, my luck is better than average at welding cast. I you want specific information, please email.

[Jerry P.]

Many thanks Sean and Hawk. Nice to her that someone else is crazy enough to have taken on welding of cast iron. Also appreciate the full spec on the nickel rod. Now to locate it. Will keep you all in touch as to my progress. thanks again.

[Seth]

I've actually suceeded in welding cast iron with my little flux-core mig machine. Granted, the cast iron wasn't extremely hard, but I actually got a very good weld. The piece was a gearbox off a farm hayrake that I had broken a chunk out of when I hammered on it to get it off the hayrake.

If you do have a mig, that would be the first thing I'd try. Of course you'll want to clean the metal pretty good. I've never actually welded cast using nickel rod and an arc welder, but I've heard lots of good things about it, so you probably can't go wrong that route.

[Jerry P.]

Seth: Thanks for the tip. I will put my MIG welder right to work on it; will let you know.

[Ken Wickliff]

Seth, I'm glad you mentioned welding cast iron with a mig. I just purchased a MM175 and I've had in my shop a cast iron birdbath thingamajig that a friend dropped off several months ago for me to fix. I'm going to try it and see what happens. The first time I welded cast iron with a stick I was pretty proud of myself until I heard this " PING " sound and the whole thing had come apart ( didn't know about preheating back then ! "...Ken :D

[Jerry P.]

ken: Please let me know how you make out with your MM175 and fixing the bird bath. I use a MM210 but have been out-of-town this past week and still haven't the chance to get to it. Maybe we both can get a handle on this stuff.

[Seth]

I can't by any means say that I'm an expert when it comes to welding cast iron, but I do have some basic info that could be of use.

It isn't the process of casting the metal, rather than rolling or forging it that makes cast iron so brittle and hard to weld, it is the carbon content. Most cast iron contains 3-5% carbon, ten times the carbon content of mild steel.

Since it is the carbon content of cast iron that makes it difficult to weld, cast iron can very greatly in the carbon content. For instance, and cast iron engine block will likely have far more carbon than an old barn-door latch. This means that your results and the method used to repar the piece will vary greatly from project to project. If the cast iron contains a fairly low percentage of carbon, you can probably get by with just taking it easy and zapping with a MIG. If it is of a higher carbon content, then pre and post heating may be necessary, as well as a more condusive weld process, such as nickel arc rod, or oxy-acetalyne cast rod.

Feel free to correct or add to my simple explanation of cast iron.

Seth

[PISTOL8]

hey guys we've been welding exhaust manifolds for years with our migs. just last weekend i welded my neice's on her toyota. we put them in the gas grill after we grind our v's and prep everything we leave them for about one hour on high and then weld them right on the grill and then close the grill and let it cool slowly. never had one break yet! (probably should not have said that) if they are broke completly in half we bolt them to a piece of 3/4" plate to keep them flat.

[Jerry P.]

Pistol8: Sounds like you have a combo of everyone's method. MIG + heat. The only thing missing is the nickel electrode but then again this is with a stick welder. Sounds like it's worth the try. thanks!

[Seth]

I've gotta say that the grill method is pretty ingenious idea.;) I would like to know though, do you weld it all in one pass, or do you weld an inch or so at a time and let the localized heat from the weld dissapate before you proceed?

Just got my MM251!:D
Seth

[HAWK]

Originally posted by PISTOL8
hey guys we've been welding exhaust manifolds for years with our migs. just last weekend i welded my neice's on her toyota. we put them in the gas grill after we grind our v's and prep everything we leave them for about one hour on high and then weld them right on the grill and then close the grill and let it cool slowly. never had one break yet! (probably should not have said that) if they are broke completly in half we bolt them to a piece of 3/4" plate to keep them flat.

PISTOL8,

What wire are your running in the mig? I've used ER70-S6 for other than commonly intended welds: non-critcal A36 to SS304, filling in gouged T1, and some other oddities. I just had not thought about trying it on cast. Have you or anyone checking this post tried any nickel alloy flux core on cast? If so, what procedure and what results? I have a client with a broken leg on an antique stove. I'll probably just V out and go with 3/32" 55% or 99% nickel rod. Hope to hear from you soon before I do this job. I may try the mig.
The stove is too big for the grill trick. May have to preheat and post heat with oxy-acetylene. Let me know.
Thanks.

[PISTOL8]

HAWK AND SETH FIRST QUESTION: I WELD IN SHORT WELDS 3/8" TO 1/2" AT A TIME AND FLIP THE JOB OVER DO THE SAME ON THE BACK AND KEEP THE PIECE HOT EITHER ON THE GRILL ,I JUST LEAVE IT ON HIGH WHILE I'M WELDING OR WITH MY ROSEBUD ON MY OXYACET. TORCHS. I'VE FOUND THAT EITHER ER70S-6 OR ER70S-4. -4 IS MY PREFERED WIRE IT DOES NOT HAVE AS HIGH A FRACTURE RATE IN THE STUFF WE'VE DONE(NOT A SCIENTIC TEST JUST IN THE FIELD USE)HAWK I THINK THE PYREX CUPS ARE THE BEST THING SINCE SLICED BREAD MOST OF THE TIME YOU CAN'T TELL THEIR THERE. I FOUND SOMEONE WITH THEM AND THEY LET ME TRY THEM. I ORDERED 3 SETS FROM TIG DEPOT. I'VE USED FLUX CORE BUT MY RESULTS HAVE ALWAYS BEEN BETTER WITH SOLID. 3/32 99% SHOULD GIVE BEST RESULTS ON THE STOVE. PISTOL8 P.S. THE TEMP.IS 96 AND THE HUMIDITY IS 96% AND 2 DAY RAIN NOW 6.4" I'M COMING TO TENN.

[Machine Head]

Originally posted by Sean Brown
My experiance TIG welding Cast Iron is that it doesn't work. If you pre-heat and post-heat the castings well, you may be able to stick them together but the weld will be porous and full of voids (all of mine were). I know a guy who tried to weld a cylinder head using TIG and it turned out like crap too. If you use a stick and pre/post-heat the thing as above, you should be able to make a decent weld providing you use the high nickel rod as ROCK says.

The right way to do it is with a torch and actual cast iron rod (something like Welco Cast-Weld or similar). You have to pre and post heat the crap out of it to keep it from cracking. Usually they post heat over 12 or more hours from 1,200F to make sure all the stresses are relieved. My experience welding cast iron with TIG is this, first: use a carbide cutter to vee a groove and not a grinder, (grinding tends to smear the graphite in cast iron and contaminates the weld making it porous). Second: i've had good luck with a nickle tig rod (1st choice easier to machine) or silicon bronze (2nd choice usually harder to machine). Third : try to position the weld so that you are traveling uphill (bottom to top) so that trapped gasses may vent ahead of the puddle and not into it. If all this fails, try gas brazing.

[smoothaswax]

I did a bit of cast iron welding through my welding courses in college, and learned a trick from my college welding instructor. Get the electrodes that are nearly all nickel and used for welding cast iron with arc welding. Remove all of the flux from the electrode, and then use the electrode as your filler material using a TIG welder. This gives you a lot more control of your bead, making a much smoother weld. also be sure to peen the weld with a chipping hammer right after welding also to relieve stress on the weld.