"dadiOH" wrote in message
news
UEZh.3980$IJ3.412@trnddc07...
It's called "weathering". And yes, it is primarily the result of
sunlight...no sun no (or little) weathering. I made a teak dash board
for my car in 1992, varnished it and have done nothing since. Still
pristine.
Apparently windshields have some type of filter and or indirect light does
not affect the finish. Some automatic tenting prescription glasses will not
darken behind a windshield.