Epoxy for coating a radiator?

mitch_04

Learnin'
Can epoxy be used to coat a radiator, or will it affect the cooling? I have a brass one from a '70 Datsun 2000 that needs to be prettied up.
 
I have black epoxied many radiators, some like the corvettes, I leave in epoxy, some like the old Ford and Chevy I cleared the epoxy to make it look like a base clear.
I have never experienced an over heating problem and i can't see where it would be any worse then the black enamel that comes on them from the factory.
 
I recently did a 35 Ford radiator in spi black epoxy, followed by clear, and it turned out great!
 
Sounds great, just what I was hoping to hear! I saw Eastwood sold a specific radiator paint, but it's my guess that Eastwood is selling the same black paint for a higher price under the guise of specialty use.
 
mitch_04;33973 said:
Sounds great, just what I was hoping to hear! I saw Eastwood sold a specific radiator paint, but it's my guess that Eastwood is selling the same black paint for a higher price under the guise of specialty use.

They probably repackage that same paint many times calling it all sorts of things :)
 
Hello, at the moment, I'm contemplating the idea of painting my radiator. While conducting research online, I came across paint that seems to hold promise. However, due to my limited experience with such products, I would sincerely appreciate your opinion to avoid any potential mistakes. Thank you kindly for your assistance.
 
Wow, a 9 year old thread! In the spirit of bringing up old topics, back in the 90's I knew a radiator guy, really cool dude. Radiator repair is just about a lost art now as far as I know. But anyway, what blew my mind is that he thinned his radiator paint with gasoline. Not something I would ever do or recommend. The paint on his radiators would stay sticky until they were put into service and got hot enough to cure out. After finding out about this, I began ordering mine with no paint...
 
I read somewhere that was stated a radiator painted black actually operated more efficiently because black surfaces transfer heat better. Not sure I buy into that considering epoxy, eurethanes or any paint do not. One thing I did learn as a young lad racing slot cars we would rewind motor armatures and coat the windings with epoxy. They did hold up much better to the heat. I believe that may be because the copper windings originally only covered in shellac were better insulated electrically with the epoxy coating and less prone to shorting out... I suspect they ran hotter.
 
I read somewhere that was stated a radiator painted black actually operated more efficiently because black surfaces transfer heat better. Not sure I buy into that considering epoxy, eurethanes or any paint do not. One thing I did learn as a young lad racing slot cars we would rewind motor armatures and coat the windings with epoxy. They did hold up much better to the heat. I believe that may be because the copper windings originally only covered in shellac were better insulated electrically with the epoxy coating and less prone to shorting out... I suspect they ran hotter.

This is true, black does transfer heat better than any other color. I painted my 11" drum brakes flat black to reduce heat build to help reduce brake fade. I read about this in an old Popular Muscle car magazine. A light coat of black on a radiator isn't the end of the world, however, the cooling fins are looking for cool (er) air to be most efficient. Anything more than a dusting of paint on a radiator will reduces the cooling effect.

I think of it this way. Put a fan in front of a radiator blowing cool air over the fins in their non painted natural state. Now put a radiator blowing cool air over fins that are painted. Which radiator fins will cool the fastest? I'm thinking it's the fins without paint because there is less material that has to be cooled.
 
I'm glad it was approved. I learned something new today and it also shows people are searching the site.
 
It depends on the method of heat transfer. Radiant emitters painted black vs. some other color--yes in some instances and in some temperature ranges and environments. Automotive radiators are not radiant--they are convective. Massive fans inducing air flow through them and the relationship to the physical size of the radiator and the amount of cooling fins in them makes painting them with any "sull" thickness of paint pretty much irrelevant. Unless you hosed paint on one of these to the point where it was so thick it impeded airflow--not much to be concerned about.
 
I have always considered radiators a kind of "wear item" and have never thought to make them too beautiful. I want them to have the thinnest coating on them that they can, and so have never painted them with anything other than something like SEM 39143 Trim Black if anything at all.
 
The radiator that came with my GTX is red. Obviously not a match to the color scheme so I will need to paint it black.
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I was thinking reduced epoxy primer but now I'm not sure.
How would you prep it for paint? Hose it down with W&G remover? No way to sand all those little fins.
 
If there is such a thing as a radiator shop in your area, you might have them rod it out and reset the headers. Just ask for no paint, their dipping process leaves the metal clean and tidy.
 
If there is such a thing as a radiator shop in your area, you might have them rod it out and reset the headers. Just ask for no paint, their dipping process leaves the metal clean and tidy.

Absolutely correct.
 
Search emissivity. A flat black surface absolutely radiates/dissipates heat better than bare metal or other colors. Scientific fact.
 
i have fought heat for 40 years building streetrods. one thing i have found is a bare aluminum radiator works best. if you must paint it put the thinnest coat possible. thick paint stops the brass from doing it's job. air flow is king.
 
I do a lot of welding and fabrication for a local radiator shop. Guy has been doing it for decades and they do know what they are doing. They have a special paint they use when they recore radiators, it’s flat black and looks OEM when done.
 
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