Painting a radiator

Hello,

I have large, old fashioned cast iron radiators in my house. They were all painted at some time or another, and I would like to repaint them. Most of the paint is in decent condition, but there are certainly a few chips and some flaking paint.

My radiators have a surface temperature of about 120 degrees in peak heating season. Is that too hot for a latex based paint? Are there particular primers and paints that I should use?

I have used the high temp rustoleum spray paint in the past and the results were mixed. And again, do I need to use high temp products given the peak temperature of the radiators?

Thanks!

 

Latex paints are not good, get them clean (sand blast) prime and paint with Rustoleum primers and paint and your good!

 

I wouldn't trust latex paints on cast iron. Not sure how they would fare with the heat but latex has virtually no rust inhibitive properties and oil base dries to a harder finish than latex does. [will wear better]

While removing all the existing paint will produce the nicest looking job, it's normally acceptable to sand/scrape and repaint.

 

Sandblasting is definitely out of the question. Removing the radiators is near impossible, and I don't intend to sandblast inside the home.

I'll consider oil based. There really isn't a rust issue in places where the paint has chipped, but that doesn't mean oxidation isn't occurring, and a harder finish seems preferable for sure.

 

For what it's worth, I've had 50+ cast iron rads painted with standard indoor latex paint with no issues. The only prep was scraping to get any flaking paint off.

Mark is definitely the expert - and I'm sure oil-based paint is a better solution, but I haven't seen any issues with the reasonably low temperatures that hydronic systems get to. (Steam heat is probably a different story).