On Sun, 14 Nov 2004 14:56:38 GMT, "Wade"
wrote:

I have several lights throughout my house which have burn/black spots above
the bulbs on the ceiling. The bulbs range from 6 inches in the bathroom to
1 foot in the hallways from the ceiling in each candlebra. I reduced the
bulbs from 60 watts to 40 and in some cases down to 25 watts on the ones
which are 6 inches from the ceiling (in the bathroom). This hasn't helped.
The house and light holders are original, about 20 years old and the spots
were not there when I moved in 5 years ago...at least not to the degree they
are now. Have the bulbs changed to burn more hot or am I just buying low
quality bulbs? I can wash the ceiling and block it out & repaint, but I
don't want to do this if is going to happen again. I really don't want to
change the style of lighting at this time. Any thoughts/ideas would be
appreciated.

Wade

It sounds to me as though the heat from your light bulbs may be
creating dark patches on your ceiling in the same way that some
baseboard heaters create dark patches on the walls above them. There
is a scientific explanation for the baseboard heater patches which I
can't fully remember. However, I seem to recall that the temperature
differential between the wall and the heated air causes extremely tiny
airborne particles and the wall to acquire opposite electrical
charges. The charged particles are drawn deeply into the wall finish
by the force of attraction between opposite electrical charges. The
tiny particles are absorbed so tightly into the finish that it's
impossible to wash them out. If you can't get the ceiling spots clean,
then this phenomenon may be occurring in your home.

I'd look for ways to reduce the quantity of airborne particles and
would also look to minimize the temperature differential between the
ceiling (more insulation?) and the air warmed by the lights (cooler
bulbs?).