Melted Mounts

[P3D emdesher <emdesher@xxxxxxxxxxxxxxxxxxxx>]

Following the thread concerning melting plastic mounts, undoubtedly the 
problem lies mainly with malfunctioning projectors: inadequate fan 
cooling, heat absorbing glass missing or misplaced, etc.  However, a metal 
mask has definite advantages over its plastic rivals in regards to the 
overheating problem.  According to a manufacturer of aluminum foil, it has 
the following characteristics:
Melting Range......................................1190 to 1215 degrees F.
Reflectivity for white light, Tungsten filament lamp............85% to 88% 
Reflectivity for radiant heat; from source at 100 degrees F............95%
Thermal Conductivity.........................53 CGS units at 25 degrees C.
Aluminum is also: unaffected by exposure to light, shrink proof, non-toxic,
emits no chemical flumes, and completely opaque insuring a black border in 
projection.  Dennis Sherwood


------------------------------