Arc welding cast iron

[skotl]

This is off a large bench attachment. Would I be able to stick this with iron rods, and would I need to preheat the whole piece?

Would a mapp gas torch get enough heat in?

 

[hotponyshoes]

Looks a bit rusty, does it clean up ok?

You can arc weld with something like a 312 rod.

Any preheat will help, use whatever you have

 

[Porkypine]

Just did a similar thing with a bench, i used nickel rods, a few passes, it spits a bit but worked fine. I didn't bother to pre heat and there weren't any issues as a result. obviously as stated you'd need to do a fair bit of clean up !

 

[Pete.]

I've got some puddle welding rods but you'll definitely need oxygen acetylene for those and I think there's a special flux

 

[skotl]

I've got some puddle welding rods but you'll definitely need oxygen acetylene for those and I think there's a special flux

Really? That’s not quite as reassuring as the other posts

 

[Porkypine]

Tbh, I'd got the easy route, Arc it with some nickel rods.
With a decent prep it should be fine. have a practice on a bit of scrap first, as I said I found the rods were a bit fierce !

 

[Parm]

I repaired a cast iron signer sewing machine stand a few years ago, plenty of preheat with a propane torch then brazed it up with oxy propane and some brazing rods I had. Took a few goes, then I got the hang of it and job came out good.

 

[zzr1200]

Prepare clean joint/preheat/TIG braze if available???

If not a day trip out, to doubleboosts'

 

[Bsmith]

If you have oxy acet or oxy propane, braze, if not preheat with propane torch till dull red and weld with nickel arc rods.

Just noticed it is mapp gas you have, so long as you can preheat mostly the broken edges, after grinding a small vee it will be ok for arc rods. Allow to cool slowly, we used to dump bits in the blacksmith forge ash, but if you have a fire blanket or something to wrap it in.

 

[BrokenBiker]

I'd arc weld it, either 312 or nickel rods, mapp torch will help, maybe not as hot as it would ideally need to be but it definitely cant hurt...preheat, weld it out and then wrap it in a fire blanket or cover it in sand to slow the cooling down.

It will either work, or be just as broken as it is now but to me it would be worth the hour to have a go and see if it works

 

[Bsmith]

Have you considered bolting a piece of mild steel angle on instead, maybe even make the whole piece from steel?

 

[Dragnet]

Carbon arc braze - I got into it because of needing to repair a cast iron saw sharpening vice, and had heard all the stories about cast iron being impossible to weld. With two gas torches on it and fire bricks we couldn't get it hot enough. With the carbon arc torch, it might be old fashioned but it certainly did the trick with no problems!

 

[Erie Fred]

Really? That’s not quite as reassuring as the other posts

That may be a true statement.
However, Gas (or TIG) welding Cast iron, with heavy pre-heat, and cast iron rods with flux
is a very good weld, and is used in engine head crack repairs.

Is it warranted for the OP ?
Maybe, Maybe not.

 

[minimutly]

Lol, as usual, so many ways to solve the problem it presents a problem of it's own...
The trick is to separate the pro's from the have a goers, before seeing if you have the kit the pro's suggest you use...

 

[skotl]

Lol, as usual, so many ways to solve the problem it presents a problem of it's own...
The trick is to separate the pro's from the have a goers, before seeing if you have the kit the pro's suggest you use...

Yep. My only options are arc, (maybe) brazing or JB Weld. Oxy and TIG are no-go cos I don’t have it and the cost isn’t warranted.
TBH that is why I posted this in the arc section….

 

[masleeve]

Skotl I have some Nickel rods that I have used to some success on cast iron , usually involving some preheat and some sand to let it cool down slowly.
Would you like me to pop some in the post for you to play with .

 

[zzr1200]

Yep. My only options are arc, (maybe) brazing or JB Weld. Oxy and TIG are no-go cos I don’t have it and the cost isn’t warranted.
TBH that is why I posted this in the arc section….

Carbon arc brazing attachment for an arc welder would work, but it can be messy and awkward to use due to their size/design.

You would still need to preheat the main frame.

 

[skotl]

Skotl I have some Nickel rods that I have used to some success on cast iron , usually involving some preheat and some sand to let it cool down slowly.
Would you like me to pop some in the post for you to play with .

Thanks. Let me check as I have a vague recollection of buying some ages ago.