Originally Posted by george blair
This has happened to me twice in my 86 soverign.the first time was in the curved front window and just this spring in the door. These are apparently shatters due to temperature and stress.
Tempered glass windows, can shatter by themselves.
The usual cause is a fracture of the surface temper, that you cannot see.
That fracture can be caused by a simple grain of sand hitting the glass hard enough.
Then, with daily ambient temperature changes, the invisible temper fracture says "that's enough", and then the glass simply shatters.
Regular glass is not tempered, therefore a scratch or a gouge, or even some sand blasting, will not cause it to break.
Not so with tempered glass.
Keep in mind that sand, dirt etc, from passing vehicles, can and does get to the trailer when being towed.
Strange as it may seem, small rocks usually will not bother tempered glass, and yet a grain of sand will fracture the temper.
And so it is.