"john smith" wrote in message
...
Bill Daniels wrote:
The following is from Bellcore. The first number is the solar energy
absorbed the second is the low temperature heat radiation. As you can
see, polished alumunum absorbs only slightly more than white paint but
radiates only 6% as much heat. In other words, although it absorbs
little, it radiates much less so it heats up more than any painted
surface.

Polished Aluminum .15 .06

White .14 .97

Yellow .30 .95

Cream .25 .95

Light Grey, Green Blue .50 .87

Med. Grey, Green Blue .75 .95

Dark Grey, Green Blue .95 .95

Black .97 .96

Hmm?
You think this may be why so many airplanes are mostly white?

It is absolutely why composite aircraft structures are white. My white
carbon/glass composite glider has a structure thermometer. The POH states
the maximun structure temperature at which a flight can begin.

The next time you have a chance to look at some old cars, compare the white
ones to, say, red ones. White paint seems to last forever. White paint
reduces air conditioning requirements and in turn increases gas milage.

Bill Daniels