Why are radiators painted silver?

HeatingHelp

Why are radiators painted silver?

Ever wonder why so many of the old radiators you see are painted silver? Paint that contained flakes of metal (aluminum or bronze) had a way of cutting a radiator’s output by 20 percent so they started painting radiators that distinctive silver color.

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kkrrjr

Damn, and when some oldtimer said the paint made the rads better, I believed him. The catalogs said you had to use thier special paint and I believed that. What a gulable kid I was way back then. Thanks for straightening me out.

DanHolohan

I guess if they were oversized it did make them better. Thanks for reading me!

Henry

My father always had a can or bronze or aluminium paint in his truck.

TMcGroy

Thanks for providing a concise answer. Since buying a house with radiators painted silver, white & pink 23 years ago, I've been trying to find out what one color I should paint them to achieve the most efficicency.

Now, can someone tell me how to remove the chipped & worn (presumably latex) paint with rusting metal underneath in the bathroom? Then, what should I seal it with to maximize efficiency & prevent more rust?

Thanks.

Erin Holohan Haskell

@TMcGroy - A lot of pros recommend sandblasting it or having it taken somewhere to be sandblasted and powder coated. Here's more info: https://heatinghelp.com/blog/how-to-paint-an-old-radiator/

Nimrod66

I've been hashing this subject over with some friends who are engineers. They contend that radiation is such a small component of the output from a cast iron radiator compared to convection that paint color would have a negligible impact on radiator output. Radiators may have been painted silver because a lot of folks believed in a heat retention theory, but it is likely not true, based on what my engineering buddies say, that reflective paint reduced heat output noticeably (or that another paint color then increased radiation noticeably).

DanHolohan

From an old radiator, radiator was 40% and convection was 60%. I've read that in every old book I own.