Re: Windows/Racer's Tape

[George Dalby <grd19@xxxxxxx>]

Actually only the front windshield is safety glass which is two nested
pieces of annealed glass with plastic laminated between them.  The side and
back windows on the other hand are are tempered glass.

The tempering of the side and back windows increases its strength by about
a factor of 10X so as to reduce breakage.  The tension introduced into the
glass between it's outer surface and the inner core of the tempered glass
is what causes the glass to break into those small pieces once it starts to
crack or break.  The idea is to make the sie and back windows much more
resistant to breakage but then for the glass to breakup in small pieces
rather than more dangerous shards.

The front windshield has other considerations, begining with good idea at
highway speeds to have the windshied turn into a shower of small pieces of
glass directed into the drivewr's face when a stone hits the windshield.
The comnbination of the annealed glass with the plastic laminate keeps the
windshield whole when that stone stricks it.

Did you ever think about how many windshield you've seen with cracks and
chips in them (but are still held together) and then wonder why you've
never seen a cracked side or back window?

George Dalby
MultiVex Mirrors


>Alix finally figures out racer's tape:
>
>>Date: Tue, 15 Dec 1998 19:22:21 -0500 (EST)
>>From: Alix Sebesta <asebesta@domain.elided>
>>Subject: Re: Beer as a measure of work
><snip>
>>BTW, thanks everyone who answered my silly question about taping
>>headlights.  So now the inevitable question comes, why don't you tape
>>the windshield too?  = )
>>
>>Alix
>>'86 325e
>>forgive my insanity, it is finals week after all  *4 down, 3 to go*
>
>Need I point out that the windshield, as well as the side and rear
>windows, are safety glass, designed to break into little tiny round pieces
>upon impact?  Much less risk than the glass from a broken headlight.  Of
>course, in the event that you get one of those non-OEM windshields
>made from inferior glass, taping the windshield would be recommended,
>right?   :^)
>
>Scott Miller
>Golden Gate Chapter
>BMW CCA #44977

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