The OH turned off one of the radiators last night in an uninsulated room, and it hit -20C, so the radiator froze solid.

This morning, it looks like there’s a crack down one fin, and water’s leaked out – the crack’s about 4″ long.
A fair amount of comments online say it’d have to be replaced, but they’re hard to come by at the moment.
Anyone have any experience of trying to repair cast iron radiators? Any words of wisdom?

Do you have access to gas welding equipment and brazing rods?

um… no.
JB Weld is about the best I could do, I reckon.

I wouldn’t be asking, except it took 3 months to find (mainly due to size), weighs around 300lbs, and cost $800 to get it pressure-tested, primed and fitted. And it’s only been used for about 4 months…

Unfortunately, sounds like I’m going to have to go through all that again

As has been said, brazing is probably about the only way of getting it fixed. Due to the size, you would need a fair amount of pre-heating I would expect, so cheap equipment isn’t going to cut it unfortunately.

Talk to your local welding shop, might not cost an arm and a leg.

Cheers, Rich

Where are you?? Canada? Eh.

You could try JB weld, but I would imagine the risk of a subsequent leak filling the house with water whilst you’re at work would would be unattractive.

Cast iron can be repaired with welding, but is very difficult. Brazing would likely be more successful. Either way it’s a specialists job and I guess you’ll have to remove it from the house. Try looking for someone who does repairs to cast iron engine blocks or exhaust manifolds.

Yup, Toronnoh.

As you mention, if the radiator subsequently flooded the house it could cost more than that to repair.
Gahhh…