What about a radiator cover instead? There's a company online that makes steel rad covers to order, and maybe you can get it in a color you like...they say paint degrades the efficiency of radiators over time. I wish I had bare radiators like yours--mine are encrusted with decades of paint! I'm going to have mine sandblasted, thanks for the idea!

"...they say paint degrades the efficiency of radiators over time."

It actually improves the heat transfer from the radiator to the air.
The emissivity of paint is much better than bare metal.
The paint film thickness is so small it has essentially no insulating ability.
Darker paints are better, but even white is better than bare metal.

Hi,
Get some rattle cans of various metallic enamels and have at!
If you want to spend more, have them all sandblasted and painted with automotive type paint. Spraying is the way to go with radiators.
In terms of heat efficiency, it's probably nearly-negligible, but an unpainted cast iron radiator has more surface area than a painted one. HUH? yes, because painting fills in all those little irregularities and pores in the cast iron. I bet more surface area equals more heat output. The old radiator paints (yes, there used to be a type of paint just for heat radiators) was a very thin metallic wash; bronze powder with very little "vehicle" -- with just a coat or two, it didn't fill in all the pores.
Casey

Anyone try matte black? Would that look wierd?

I would bet good money that the top one's paint job is original.

For what it's worth, the top pic is the exact same color of all my radiators. (My house was built around 1908.)

"For what it's worth, the top pic is the exact same color of all my radiators. (My house was built around 1908.)"

And I'd bet that the paint on yours (actually a pigmented varnish, IIRC) is all original, as well.

Most of the radiators in my parent's house still have the circa 1910 finish on them.

OK...found some pretty neat stuff online about different multi-step processes with powder/some type of lacquer, etc. Different two-tone processes as well.

Instead, I just tried out a couple of different types of Rust Oleum and found one I think will look pretty neat--Rust Oleum Hammered Finish in Brown. Looks really cool on cast iron, from what our friend showed me at his shop. I'll post pics of the radiator once he's done spraying it with his auto body spray gun tomorrow. Will it be truly authentic? Nope. But it'll hopefully look a heck of a lot better than baby blue on a radiator!!

:)
Sarah

kframe, that's very cool to know. I had some painters out this summer and they asked if I wanted the radiators touched up. I'm glad I said no.

Oh...if this one had the original finish, I would have kept it...in a heartbeat! But some p.o. painted it baby blue and it was flaking all over. After sandblasting, it needed some type of paint to keep it from rusting. Even if that doesn't let through quite all of the head, it'll be plenty warm in our small bathroom--the radiator was put in to heat that room and the one next to it (before the indoor plumbing). Now that bathroom has a pretty big heater and the small room next to it (now the laundry room) has none.

Anyway, I did wind up having a friend with an auto body shop spray paint the radiator with Rust Oleum Hammered Finish in Brown. Looks REALLY good!!! I'll take pics of it later...really nice dark brown/bronzish color.
:)
Sarah

Most existing radiators are oversized but for where they are not and increasing the amount of radiant heat output is important, you should avoid paints with aluminum in them because the finished surface has such a low emissivity that it will reduce the radiant (infrared) energy output. Any other paint in any color should be fine.

Covering a radiator is feasible only if it is greatly oversized or if it is open at the top and bottom and the covering contains no aluminum.

Hi Sarah...
I'm Sara too, and have the same situation, a 1902 house full of original radiators but two are heavily painted and chipping, the rest look great.

I'm dying to see photos of how the brown hammered finish turned out, can you post one??

Many thanks

Here's two pics of the radiator...I really like the way they turned out. They're a little browner in real life, but it's still pretty accurate, despite the flash.

{{!gwi}}

Nice thing about this paint is that you don't have to prime or sand (we did, though...and used a gray autobody primer before) because it can go right over rust spots and smooth spots.

If you want dark gray, you could also get the one that says "black"--more like a dark charcoal/gray.

Sarah

We too live in a historic home, one which is heated with hot water and has all of it’s original radiators. Ironically, I was just reading an article about this very same topic, as all of out radiators are painted a glossy

off-white and I’ve rec begin to notice some of the paint chipping in places. To give you the short version of the article, the author basically concluded that radiators painted with non-metallic paint produced a higher heat level than radiators painted (or even left bare) with a metallic paint. (they measured it and the difference was nearly 100°) The reason for this is b/c metallic bounces off light particles while flat colors like white & black do not.

The very last thing I would ever do would be to cover up these iconic mini pieces of art with radiator boxes, but that is a personal choice.

I think I read on This Old House that you need special paint designed for heat/radiators if you want to paint them.