• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Has any one tried black paint?

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.


Mar 5, 2001
It has occured to me that when I was young and into building hot rod engines, the rebuild manuals always said to paint the engine inside and out with black paint. The reason given was that black absorbed heat more readily than any other color, therefore, they reasoned, it would help to disapate heat more efficiently from within the engine to the outside. I know that all the top engine builders then used to do this, and anyone I ever asked said that it did indeed make the engine run cooler in their hot rod applications, where the engine was generating much more heat than normal.

My idea is this. What if you were to paint the inside of your case black, and maybe even the outside too? Would it help? It does sound reasonable, but I have been unable to find anyone who has tried this. Any thoughts, suggestions, experiences?
Bob, with proper case ventillation, I doubt much heat would be absorbed from the IR radiation within your case and re-radiated from the outsides. Having cool case walls from being in a cool room does help a little with system cooling, but nothing like having a good flow of cool room air through the case. My case interior typically runs about 2-4 degrees above room temp. It makes it easier for the HS to give up the heat it has wicked away from the CPU.

Good point. I guess super hot oil curculating in an engine is one thing, air is quite another.

Okay then, how about a black anodized HS? I have seen them, and have one on my video card.
I have never personally experienced, and only read once in a review of the Thermosonic HSF, of irriditing, annodizing, or painting enhancing heat conduction. My experience has been that if you put a coating on the material carrying the heat, aluminum, copper, etc., it adds another thermal barrier between that material and the air you want it to come in contact with. I think that all that can be said regarding irriditing and annodizing, is that they have a minimal negative impact upon heat transfer, certainly not an enhancement. Painting, depending upon the type of paint would have a slightly worse impact.

Okay, thanks for the info. I prefer the "shade tree" method as to me the entire point of O/C'ing is to get more for le$$.

Thanks again.
I agree with the extra paint having a worse effect on heat conduction.

The best heatskins are the pure copper untreated heatsinks, they seem to give the best transfer.

The hedgehogs are excellent heatsinks, just don't seem to perform as wel as the Alphas or the TheormoEngoine range.

Must be in the design. They are not as good, but only by the tiniest fraction, See below attached chart from OCuk.
I agree with the others here.

From a heat transfer standpoint, you will have very little IR radiation dissipation from your heatsink at the low temps we are talking about. However, the paint will add another convective and conductive resistance to the thermal circuit, which will reduce the amount of heat transferred from the heatsink to the air (i'm assuming that the cpu/hs interface is not painted here). I have done real world tests with anodized AL vs black painted AL (matte finish) in forced convection tests and the anodized kicks the painted HS's *** in all cases. Sorry, no numbers, only non-dimensionalized results.

next thing you know forum moderators will start talking about putting polar bears on cpu's.....as a side note, i think that was the funniest thread i've ever read anywhere.