To paint aluminum you need a self etching primer. Otherwise with regular primer it will not turn out.

 

I'm sure you can, but the question would be why would you want to? The bare aluminum is what you want fior the best heat transfer.

 

i'm sure you can, but the question would be why would you want to? The bare aluminum is what you want for the best heat transfer.

x2!

 

Bare aluminum may not be the best for emissivity. Here's a paper titled:

Infrared Inspection Techniques for Evaluating Polished Metal Objects and the Implications for Decreasing Operating Temperatures

http://www.flirthermography.com/media/2003_VoitlFINAL.pdf

Other tests:

http://www.molalla.net/~leeper/coatbar.htm
http://www.furukawa.co.jp/review/fr026/fr26_13.pdf

 

"generally speaking" .. . if you have a HOT object, hotter than the items around it, and you want it to give up heat, then try to simulate a 'black body emitter'... ie.. paint the object a flat black.

Conversely, if you have an object that is 'cooler' than the objects around it, and you want it to reject 'radiated heat' from other objects around it, then make it white/shiny/reflective... Heat energy works similarly to light energy.... with the differences associated to the longer wavelength of the heat energy...

 

Overspray and imperfections can be taken care of, but may take some work. The aluminum can be polished. Where is the overspray? Is it where it will be seen? I use to polish the aluminum parts on my Harleys before they had chrome this and chrome that. Overspray can be wetsanded with very fine grit paper. Then if you have access to a bench grinder with polishing and buffing wheels and rouges you'll be amazed what you can do. If you look in the cooling and heating sect. and search "entropy and dual fans installed", I have posted some pics of my radiator set up. I polished the top and side tanks of my radiator. They had a duller finish to them. The smoother you can make the surface before polishing the better. But you can always go back and resand then polish again until you are satisfied. What radiator did you get or do you have a picture of something similar?

 

Is the over spray on the fins or the tank. If you want to keep it bare aluminum brush some paint remover (like goo gone not aircraft stripper that might etch the aluminum) and let it set for awhile. Might even use a bristle brush to help it along, brushing with the fins not against them. Take care with the brush. Don't they make combs designed to straighten out radiator fins? Then use a high pressure washer to clean. Same thing can be done to the tank and then re-polish when clean. Worth a try. You can always give it a light coat of paint if all else fails. I'd use a very light coat of flat gray or flat black if it HAD to be painted, and only enough to make it look good.

I would guess an aluminum radiator will be more than adequate to do the cooling so a slight loss in cooling by painting it probably wouldn't be enough to matter.

results may vary.....:yes: Sorta' depends what type paint the over spray is also. If it's a catalyzed paint it'll be tough.

 

A bare aluminum radiator will not radiate heat as well as a painted one. A polished aluminum radiator will radiate even less heat. Ever wonder why radiators are painted black?
That's because the emissivity coefficient of aluminum varies from about 0.04 for polished aluminum to 0.31 for heavily oxidized aluminum compared to 0.89 for black epoxy paint.

http://www.engineeringtoolbox.com/emissivity-coefficients-d_447.html

I see everyone read the interesting articles I linked above...

 

I painted the front half of my alum radiator flat black just 'cuz I thought it looked dumb seeing the aluminum rad through the black grill. Emissivity never even crossed my mind, but now that I think of it, I'm actually a lot smarter than I thought I was.

 

The paint is on the fins, and it looks like he painted something on top of it so there is a stupid pattern to it. It would not be easy to clean up without risk of damaging it I fear.

@ $100 it was worth dealing with a few bugs. Sounds like a light coat of flat black will do the trick, but after a little etching first? Thanks for the advice and interesting reading, very provocative.

-shoe

 

Just use a radiator paint, like this: http://www.eastwoodco.com/jump.jsp?itemID=125&itemType=PRODUCT

Lower solids content and won't plug the fins and/or affect heat transfer. You can buy a similar product at most any good Napa or Carquest type store.

 

For correct emissivity with an IR gun, a couple of square inches of black vinyl tape should give accurate readings. Or just aim at a hose. Assuming you have black rubber hoses. If you're just after a 'look',,,,, your car, your call.