QUESTION: Painting an ALUMINUM RADIATOR?? Cooling efficiency???

just had my model A's 29 radiator recored w/copper core, asked what they painted it with, said they use water base black, that was the best to paint radiators with??? havent run it yet.

 

this has worked well for me

 

If you're not cheating, you're not trying.

 

Did Kirk! get his radiator painted yet.....any pics?

 

anything between hot metal and cooler air will slow cooling. heatsinks for electronics are generally unfinished aluminum. anodized is common when it's visible so it won't be ugly, but it doesn't improve cooling.

here's a thread on PhysicsForum about this, for electronics heatsinks. https://www.physicsforums.com/threads/black-body-radiator-vs-painted-surface.694536/

from that page:

Both points are correct:
1. Painting an object black will improve radiation (if the object is "black" in the wavelengths being radiated). The SR-71 was painted black partly for this reason.
2. Painting an object will insulate it. ​

Reference https://www.physicsforums.com/threads/black-body-radiator-vs-painted-surface.694536/


black pigments in paint absorb infrared from the sun and get obviously hot, but i doubt that's a problem for car radiators.

i have a 1/4" thick sheet of honeycomb nomex in front of my aluminum radiator, painted red. i painted the side tanks with just Rustoleum flat black and that seems to be holding up pretty well. the honeycomb stuff is there to keep bugs out of the fins. it's held in place with a couple little Z clamps, so it comes out for cleaning easily.

i happen to have it all apart, changing front motor mounts, if anyone wants pics.

 

Using the search function to my advantage....and Rustoleum BBQ black



Can still see through it




Before....ugly



After...much better

 

I’m not fond of repeating myself but now that my RPU is on the road this stuff really works and it’s durable too.

I had my Griffin aluminum rad for my RPU powder coated in a nice black using a high tech heat dispersion coating.
I’m really pleased with it.

https://techlinecoatings.com/tech-line-coatings/industrial-coatings/thermalmanagement/

 

I use black engine paint no primer. Never had any issue.

 

Hey blue one,
It looks great,,,,looks old school to me,,,,I think you did good .
And the valve covers and the decals look awesome as well,,,,really sets it off !

Tommy

 

I remember seeing "radiator" paint forever at the hardware and auto stores. Do they still make it? As I recall, it was a satin black but the coverage seemed "thin" - just enough to appear black, not too thick to inhibit cooling. I only used it once, long ago and probably did it wrong using several coats to get better coverage.