Roger Halstead wrote in message . ..
On 4 Aug 2003 12:37:54 -0700, (Jay) wrote:

The reason your silver aircraft may have showed up so hot is because
your "heat gun" was actually peering at the image of the sun reflected
off the glossy surface. But its is true, the apparent color seems to

Shiny Aluminum gets really hot in direct sunlight.
At work we had a 1 inch thick 4' X 8' Aluminum plate laying on blocks
out in the sun. It was in a protected area where it had little
cooling. It actually got hot enough to burn a person trying to move
it. The temperature was only slightly below the boiling point for
water...bout 200 F.

I always figured shiny Aluminum wouldn't get all that hot until I saw
that.

Your perception of it being hot was based on the material conducting
heat into your fingers when you touched it. Plain aluminum is an
exceptionally good conductor of heat as opposed to a layer of paint
over the same material. Example: This guy I worked with told me that
growing up in Minnesota, they put a layer of styrofoam on the seat of
the outhouse so in the freezing winter they wouldn't get stuck. The
styrofoam was certainly below freezing when they sat down, but because
its ability to conduct heat was so small, it didn't freeze their
empennage off.

So a painted airplane could have a higher actual temperature but less
ability to make your finger feel hot when you touch it.