When welding cast iron.

[Daniel]

What do you think first.

ni-rods , 139 rods or you'll try to brazing it?

[Sonora Iron]

What do you think first.

ni-rods , 139 rods or you'll try to brazing it?

What kind of cast iron are you working with? There are 6 different types.

Nickel 99 can be cut, drilled, milled, and ground. Ni-55 can be ground. The low nickel rod can't be even ground.

[J hall]

It depends on what you are working on to some degree. My preference is brazing or Ni99. Either one takes patience.

Picture is an old Caterpillar exhaust elbow

[jrscgsr]

any of you try tig welding cast using ni99 with the flux knocked off? Seemed to work well for me on an old chevelle cast header.

[BC Iron works]

i use ni44 when tig welding cast iron

[aametalmaster]

Depends what you are welding and what process. I like Crown Alloys 255 for most of my cast work...Bob

[Daniel]

It depends on what you are working on to some degree. My preference is brazing or Ni99. Either one takes patience.

Picture is an old Caterpillar exhaust elbow

Nice job on that exhaust.

First off, I have to say that I have done a fair amount of cast iron job. I wouldn't say that I'm the best welder there is, but i can lay beads in any position and they look good. But some cast jobs just cannot be done I think. I may be wrong. I'd like as much input as I can get on this.

I had a cast job to do this week and had a real hard time with it.
I couldn't see what kind of cast it was "to answer your question Sonora iron" because it wasn't a broken off piece, it was a crack that ran along the inside corner of the key way where the shaft of a concrete finishing machine goes in to turn the big circle with the finishing blade.
Maybe some of you guys know what kind of cast it is.
So I air arc the crack from the outside a little, then used my little die grinder with the 1" long pointy bit to finish my V groove. I left a just a little shy of a 1/8 gap with a tiny landing maybe a 1/16 , I should've made my landing a little bigger, Then grabbed the 1/8 139 rod which is very machinable" lots of nickel in it, got two piece of 1/4" scrap flat bar made an open corner joint with the same opening as the V groove I had to weld then find my setting for for my rod which was around 90 amp. I had the perfect 3" long bead with perfect little penetration bead on the other side of my V groove.
I pre-heated the piece to around 600 degrees, took a deep breath and started to lay my first root pass and the nightmare began. The arc was really irratic, so had to work the arc to hit both side which made my penetration very heavy almost burn thru omg, and to make matters worse, I chipped my slag and it look like a sponge, just full of porosity.
Anyways to make a long story short I ended up trying to braze it and the brazing would stick to the 139 bead deposite but not on the cast material.
Maybe I should've try to brazed it right of the bat.

Anyways sorry for the long post. Any past experience and stories that you good folks can share with me would much appreciated

[nfinch86]

Braze It !

Hi;

I'd try to clean it up the best I could then Braze It !

[Daniel]

I tried that. Die grinder back to bare metal after heating it up lots to burn any grease or what ever that could be in. No luck.

[azmac54]

cast iron

Has anyone ever tig welded cast iron with stainless? Is it a good or bad idea?
Jim

[Portable Welder]

Daniel, If the braze would not stick then I would verify that the part is not stainless.

I have never had a problem with brazing not wanting to stick to cast.

Did you use acytelene and oxygen, did you remember that you need flux for brazing.

Just trying to give you a few ideas as to what went wrong.

Also, a carbon air arc leaves a deposit of carbon on the steel so remember to use a carbide cutter to remove the carbon residue.

It is also recommended to use a carbide cutter when preping a cast surface verses grinding, grinding smears the cast to a certain degree.

Good luck on getting it fixed.

[thunder71]

it can be done...i use the nickle base stainless stick rods ,beat the flux off & sand the rod with sandpaper...preheat part,tig it up...

Has anyone ever tig welded cast iron with stainless? Is it a good or bad idea?
Jim

[abprt]

cast iron welding

Nice job on that exhaust.

First off, I have to say that I have done a fair amount of cast iron job. I wouldn't say that I'm the best welder there is, but i can lay beads in any position and they look good. But some cast jobs just cannot be done I think. I may be wrong. I'd like as much input as I can get on this.

I had a cast job to do this week and had a real hard time with it.
I couldn't see what kind of cast it was "to answer your question Sonora iron" because it wasn't a broken off piece, it was a crack that ran along the inside corner of the key way where the shaft of a concrete finishing machine goes in to turn the big circle with the finishing blade.
Maybe some of you guys know what kind of cast it is.
So I air arc the crack from the outside a little, then used my little die grinder with the 1" long pointy bit to finish my V groove. I left a just a little shy of a 1/8 gap with a tiny landing maybe a 1/16 , I should've made my landing a little bigger, Then grabbed the 1/8 139 rod which is very machinable" lots of nickel in it, got two piece of 1/4" scrap flat bar made an open corner joint with the same opening as the V groove I had to weld then find my setting for for my rod which was around 90 amp. I had the perfect 3" long bead with perfect little penetration bead on the other side of my V groove.
I pre-heated the piece to around 600 degrees, took a deep breath and started to lay my first root pass and the nightmare began. The arc was really irratic, so had to work the arc to hit both side which made my penetration very heavy almost burn thru omg, and to make matters worse, I chipped my slag and it look like a sponge, just full of porosity.
Anyways to make a long story short I ended up trying to braze it and the brazing would stick to the 139 bead deposite but not on the cast material.
Maybe I should've try to brazed it right of the bat.

Anyways sorry for the long post. Any past experience and stories that you good folks can share with me would much appreciated

Daniel; Cast iron can be a night mare. What works one time, might not work the next time. Had an exhaust manifold that used N. 99 on one end and things went really good but couldn't beat the weld on the opposite ends even though I didn't change a thing and had to braze the other end. You could try using AC and see it that works. Sometimes gringing on metal creates a magnetic field that could give you problems. Different rods can also be a factor. Again, one might work on one job but not on another. Used N.55 on some jobs and noticed that the first pass had prosity in weld but not in second pass. Figured the rod had to get hot to weld right. Keep trying different things. Cast iron welding can be a puzzle at times.

[Daniel]

abprt, Thanks for this info. I'll remember to keep the rods hot. I wish we would have a high frequency tig at work for this type of work. But we wouldn't use it enough to pay for itself i guess. We work on mostly logging and minning machinery, so fcaw and smaw is a big part of processes we use with some gmaw.

[aametalmaster]

Has anyone ever tig welded cast iron with stainless? Is it a good or bad idea?
Jim

I just ordered 10 lbs of Crown Alloys Tig rod Royal 55/45-10 and it is 26 bucks a lb for 5 lb lots and 28 bucks a lb for under 5#. And that rod is made for tigging cast iron...Bob
http://www.crownalloys.com/page13.pdf