Bare metal on radiator

[DawnandIan]

I wondered if anyone can advise on what to do with the few spots of bare metal on radiators. The overall condition of the radiators is good, I've rubbed of some bits of rust which has exposed the bare metal underneath, I'm going to paint them with a special paint for radiators, ( just the one coat) but wondered if the bare metal/rust bits will eventually "bleed" through. Is there a product to buy that could be used just on the bare metal areas, before painting them.
Many thanks in advance for any advice
Dawn

 

[Burnerman]

Kurust by Hammerite is probably as good as it gets.....brush it on, and it turns the metal blue/black as it treats any corrosion. Then paint over - using a primer if you want.
Radiators are notoriously badly painted from new, I find, and will rust easily - especially in a bathroom.
John

 

[JohnD]

I like to use a "metal preservative primer" for ferrous metals. You will be surprised how heavy the tin is. Red Oxide is very old-fashioned now but some people still use it. I think my current one is calcium plumbate primer, or you can get zinc phosphate.

You need an oil-based primer on bare steel, because a water-based one will start the steel rusting until it is dry.

The problem with radiators is that the joints often weep a little water, and, if cold in humid areas, they get condensation. You can re-make the tail connections using PTFE tape on the threads if they are not perfectly watertight.