Cast Iron Radiator - External Rust Advice

[jimbobex3]

I've spotted this rust patch on the outside of a cast iron radiator in the house.



There's no sign of any water leaking from it on the floor, however when I put my finger on it, I couldn't say it was bone dry.

Any advice on what I should do to try and resolve this? I'm a bit fearful of touching it incase I make it worse and it starts leaking.

Sadly I don't know the make or when they were installed as it was by the previous owner. It should be noted that this is the only radiator that has this patch, the others in the house are fine.

 

[ShaunCorbs]

Are they in a damp environment?

 

[jimbobex3]

Are they in a damp environment?

Nope, it's in the living room

 

[ShaunCorbs]

Would say then the rads getting very close to pin holing time to change

 

[jimbobex3]

Is there anything I can do to clean/dissolve the rust and use some sort of sealent for a short to midterm solution? I don't really want to spend a wad of £££s on a new radiator at the moment.

 

[ShaunCorbs]

I wouldn’t say so as it’s coming through from inside out

 

[jimbobex3]

I did the tissue test today and it definitely doesn't have water coming out of it 🙏 . The tissue only showed a very feint brown colour (from the rust).

How thick are cast iron rads? I'm thinking a solution could be to remove the outer layer of rust to prevent any further spread, then add a primer coat (red oxide) to prevent any contact with the air/moisture.

I'm making a huge assumption this is external rust due to moisture and/or just chipped paintwork from the previous home owner.

Any potential pitfalls with this potential solution?

 

[ShaunCorbs]

depends if the old cast iron or cast iron effect old ones normally are 0.8-1cm thick cast iron effect 1-3mm etc

Turn the rad valves off before you do anything and then you can get a flap disk for a Dremel or other rt and then remove the rust on top and then use some rust converter and then red oxide prime etc

 

[Last Plumber]

Looking at the photo I'd say it is from within so be careful poking it.
As Shaun said, close the valves first.
If it is from within, there's not a lot you can do with it.

 

[gmartine]

It's a temporary measure but after you've cleaned it up (as above), you could patch it with a smear or two of JB Weld epoxy. That should stabilise it for a while.