Aluminium and some aluminium allloys are the only materials that respond well to anodising, although, I think magnesium does respond with mediocre results I think the advice that paint and colour has minimal effect is good advice, except that accumulated rust will eventually become a real insulator, and paint will prevent the rust buildup. RE: Which Paint Color for Maximum Heat Dissipation? saxon (Chemical) 8 Jan 03 17:59 There's a good chance that this link will provide emittance values for oxidized (corroded) bare metals AND for clean, finished surfaces of various color. I've known quite a few EEs who are stuck with the wives tale that "black is always best." The truth can be seen by reviewing the emittances published in This is because IR emission becomes more diffuse (scatters radiation in all directions) the rougher the surface gets. For example, unfinished diecast aluminum becomes a better emitter as the outside surface oxidizes. Also, once any surface is coated with oil, grease, and dirt, it certainly will make NO DIFFERENCE because it's only what's on the outside skin that makes any difference.Īs I said, it's not as simple as the color. Paints and finishes have VERY LITTLE influence on insulation (conduction). You will find that the temperature rise is VERY SMALL and not worth further consideration. 001-.010" thick layer of paint of any kind. I invite you to do a sample calculation on how much insulation value is added by, say, a. RE: Which Paint Color for Maximum Heat Dissipation? Tunalover (Mechanical) 28 Dec 02 17:07 If you need solar absorptances, good luck finding them! If you run into a good database, I'd appreciate it if you'd let me know about it! In this case, your candidate finishes would have the highest ratio of emittance to solar absorptance.įor the emittances. If the parts will be exposed to the sun, then "the plot thickens".you would then need to determine the solar absorptance (= 1 - solar reflectance for opaque materials). ![]() Most emittances listed in databases such as those identified below are determined over the IR band which contains the lion's share of the heat (even for "glowing hot" applications). ![]() You start with high-emittance finishes and then narrow the field by weighing each candidate against its suitability with the base material, temperature range, and environment. If the parts are in the shade, then why don't you go to the following link and select candidate finishes based on their emittances (according to NIST, the "ance" terminology is more correct than the "ivity" because the surfaces in question are not optically pure). There seems to be a wide variety of opinions here.
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