08-17-2018, 06:44 AM
If the unpainted metals are not heavily oxidized (corroded), then painted metals will radiate more heat since the hemispherical IR emittances of organic finishes is much higher than for unpainted metals. Radiated IR energy (heat) is proportional to the IR emittance. The higher the emittance the greater the radiated heat. The IR emittances are properties only of the finishes and don’t depend on the host material. Usually a shiny metal surface has a much lower IR emittance than a painted surface.