Struggling to weld cast iron

[TechnicAl]

If its not magnetic its not cast iron

Probably some Zinc / Magnesium / Aluminium die casting alloy

Before anyone googles it.........there is a type of cast iron called NiResist which can be austenitic (none magnetic) but its expensive and highly unlikley to be used for a casing

 

[edd]

I think you are right.
When I touch it with the grinder it grinds similar to the way aluminium does...badly!

Cheers

Ed.

 

[Debs.]

I was gifted a vertical-slide recently which had suffered a severe bang, resulting in a section of the T-slot end being broken free.
I was over at John Stevenson`s place at the time and he suggested MIG-welding the C.I repair using stainless wire.....as a test, I tried some cast-iron MMA rods first: horrible (and expensive) things they were, `ended up grinding it all out afterwards......the stainless MIG however, worked brilliantly and after few passes on the swing grinder, you`d struggle to see where the repair had been made.

 

[sardine]

I get very nice welds with pure nickel electrodes, but I go the whole hog with preheat, short bursts of weld, and burying in sand after ward.

I've got a test peice of cast iron welded like this sitting in side my wood burning stove, its been cycled hot and cold for nearly a year now and hasn't cracked.

 

[premmington]

Lincoln Reptacast 2.5mm nickel rods, preheat with propane torch, short bursts of weld! Never failed yet!

 

[Kent]

Looking at the bits where the paint has worn off I would guess its an aluminium or pot metal casting.

Yep, but init hard to tell compared to getting your hands and a file on it

 

[Kent]

Cast Iron can be welded by a major preheat under a blanket then gas welded with special Rods (I haven't seen any for years) it beat the heck out of gluing it with a different metal in MMA. My old boss used to get a stack of this work in to do but he had literally 70 years of experience. Also to fix this you might pin it or if its an Ali casting look up Loctite Hysol I think the ali stuff is 3475A, once cured you can drill and tap it etc but I have never used it in high stress situations (though was told of a third party who glued an alloy engine block together with it). I use the Hysol for bedding Rifle actions into the stocks and never had an issue with cracking etc. even with the heavy magnum calibres