Most every G.M. condenser that I have seen on all G.M.s are a shade of black, But never the raw Alum. color. Then again, I may be wrong. I am a 70 guy and both of mine were Org. a shade of black.
Both of my 70s, The only A/C part that is raw Alum. that you can see through the grill is the very noticeable " Round Cornered " O.E.M. dryer.
Bob

 

Woody,
All of the oem condensers I have seen were black but it seems like all of the replacements are not painted. I just replace the one in my 99 Tahoe. Te original was painted only on the front side and the oem GM replacement was not painted. I didnt want to see the bare aluminum through the grill so I painted it. I used Rustoleum 248903 Flat Black high heat paint. Got it at Wal Mart Worked out fine. Eastwood also sells a paint just for that purpose but I doubt if it is much different.


https://www.rustoleum.com/product-c...catalog/consumer-brands/auto/specialty-paints/high-heat?ls=248903&lc=Flat Black

 

Black dissipates heat much better.

 

I would use black lacquer paint

 

This is important! On condensers and radiators. Believe it or not an enamel will actually insulate and effect it's performance. Been there done that

 

Thanks guys, I gave a can of EASTWOOD radiator black from the radiator I just put in. I guess I will use it seeing it is meant for the heat and it is what the rad is done it.

 

From a Thermodynamics perspective, any paint will reduce efficiency.

 

If black paint is bad, Most all cars and anything with A/C on planet EARTH have black Rads, & Black A/C condensers. Someone better make a phone call, Hurry..........:surprise:
Bob

 

Most are bare aluminum now. Rads and condensors both, and other aux coolers.
IF I was painting a cooler (for corrosion protection), AND I wasn't trying to hide it, I would paint it with that fake chrome aluminum paint. Help transfer heat. Black absorbs heat, why would you want to have something that you are trying to cool down, absorbing more heat? My guesstimate is they painted them to protect the copper from corroding, and used black to make it all look uniform and to hide it in those old open grills.

 

I agree with the modern Alum. I may be better quality alum. could be High Tech. engineering on modern cars,Etc. Could it be " Lets save some paint". I do know, Most of the Alum. items, Rad, Condenser, oil cooler in my Silverado are NOT painted. As Richard Dawson would say, " Your correct answer is " ?
Bob

 

One thin coat of flat black will radiate better than unpainted. Neither will make a lot of difference, IMO.

 

Thanks for all the input. I ended up using Eastwood radiator paint on it after seeing a friends PE condenser he remove. The Eastwood paint is a liner paint just for rad. heat.