• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

no more painting

bearman

FBBO Gold Member
FBBO Gold Member
Local time
3:59 AM
Joined
Jan 9, 2018
Messages
6,203
Reaction score
6,559
Location
Phoenix
how many of you folks are painting the condenser for your a/c. finding it better not too. many of you folks already know this but for you folks that don't paint it.
 
how many of you folks are painting the condenser for your a/c. finding it better not too. many of you folks already know this but for you folks that don't paint it.
You are COMPLETELY correct! The same goes for radiators, intercoolers, oil coolers, transmission cooler, heater cores, etc. There are some paints that are supposed to transfer heat better, but even those don't transfer heat as well as aluminum/brass....not even close.
 
as long as it works for you that's good. but after doing more research none painted units do a lot better on getting rid of the heat.
 
your car is stock a/c correct. it is not aftermarket. when summer comes around can you take a temp reading at the input side and the output side. would like to know your temp drop.
 
your car is stock a/c correct. it is not aftermarket. when summer comes around can you take a temp reading at the input side and the output side. would like to know your temp drop.
Correct. Can do. I do know most of the time it blows about 34-38 degree air when I have driven it. Can’t say what the outside temp was though.
 
It's true that most paints, especially heavy coats of enamel, will do more insulating than heat shedding. However, there are paints with both high emissivity and conductivity. These also may not increase cooling, but at least do not hinder it. Uncoated aluminum or brass will eventually gather a layer of oxidation, and that oxidation can provide thermal insulation. After that happens, the properly coated radiator will likely start to look better for heat transference. Black Ice aluminum radiator paint, for example, doesn't claim to increase the effectiveness of a radiator. But it does claim protection without affecting heat transfer. https://www.dewitts.com/products/blackice
 
It's true that most paints, especially heavy coats of enamel, will do more insulating than heat shedding. However, there are paints with both high emissivity and conductivity. These also may not increase cooling, but at least do not hinder it. Uncoated aluminum or brass will eventually gather a layer of oxidation, and that oxidation can provide thermal insulation. After that happens, the properly coated radiator will likely start to look better for heat transference. Black Ice aluminum radiator paint, for example, doesn't claim to increase the effectiveness of a radiator. But it does claim protection without affecting heat transfer. https://www.dewitts.com/products/blackice
Hmmmm…… I looked at that link. I have quite a bit of experience with both epoxy paints and with radiators/intercoolers/oil coolers/etc. Here are my thoughts, both good and bad. Epoxy is a pretty good insulator, but .002" thick sounds good, though that low of a film thickness is very, very difficult to achieve with an epoxy, even a very low solids (aka high VOC) epoxy. If the epoxy is filled with copper, silver or gold AND can be applied very, very thin, it would probably have decent heat transfer. I'm a little skeptical of the claims made by Dewitts.

You make some good points about aluminum oxide & copper/zinc oxides. I haven't really looked into the heat transfer of those (lazy I guess). I do know that aluminum oxide layers are typically pretty thin (fighter jet fuselages, etc.). I will have to take your word on the insulative properties of these oxides unless I get better information.
 
PurpleBeeper, while I can agree that oxide layers can often be thin, especially with aluminum, that isn't always the case. Run that jet fighter up and down some of our salty winter roads for a couple of years and see how good it looks. :)

For me, I don't think there's a whole lot of difference anyway. If you're on the ragged edge and a bit of paint means that you overheat, you should probably look at better cooling. It's just appearance for me; I don't want to see the radiator through the grill.
 
Last edited:
Get both! I sprayed the front of my radiator with a light coat of black and left the engine side of it natural aluminum.
 
All this 'theory' is good stuff...but I can say with certainty that painting (at least for my aluminum radiator, can't comment on the A/C parts) did absolutely zero to the heat-shedding capability. Tested (obsessively, really) with different measuring devices over a period of time before and after it was painted (with regular rust-oleum satin black) and...no difference. I think we overthink this stuff sometimes
 
Auto Transport Service
Back
Top