|
Defrosting conductors can be scraped off with a razor.
Many areas require laminated glass for the windshield, while tempered is used for rear and side windows.
Tempered glass is much like tempered steel - It gets quenched while hot, although the glass requires more support. It is usually done with blasts of air, and the pattern of the jets used can be seen in polarized light. The process causes the glass to shrink first on the surface, so that you wind up with the surface in compression and the interior in tension. Since cracks start from the surface, they are held shut instead of progressing, up to a much higher force than usual. However, when one does get going, it sets off the whole piece, and the internal stresses turn it all to small, harmless pieces. It is interesting, when carrying a single patio door panel, to touch it to a bit of concrete patio. You hear a bang, and suddenly, the weight is gone.
|