Windshield safety - older cars

[Robert06]

Everyone is aware of the safety issues involved in windshields installation on newer cars - roof and structural support, air bags, etc.

What about older or vintage cars? How many of these factors apply for cars made up to - say - 1980? Did the glass contribute much to roof and structural support back then?

I have a 72 Toyota Corolla that uses rubber gaskets with the front and back glass.
When this car was built were they designing the glass to help support the roof?

Robert

[Glasseye]

Prior to Direct glazing the roof strength of a car was built into the side rails. Glass was not seen as a strength factor until the manufacturers could guarantee the front and rear windscreens would hold up under extreme stress. Nowadays, because of the latest bonding materials and techniques glass plays a more prominent part in car design. We now even have cars with complete glass roofs.

[Robert06]

Originally Posted by Glasseye

Prior to Direct glazing the roof strength of a car was built into the side rails. Glass was not seen as a strength factor until the manufacturers could guarantee the front and rear windscreens would hold up under extreme stress. Nowadays, because of the latest bonding materials and techniques glass plays a more prominent part in car design. We now even have cars with complete glass roofs.

Thanks Glasseye,

Thats what I had heard, although I didn't know the details. Do you have any idea about when glass began to be considered a strength factor - at least in the US? My 1972 Corolla is a US model (I'm in the US.)

I'm guessing that my Toyota fits into the category of the roof being supported mainly by the frame.

[streekyd]

The need for bonding windshields to the body for structural strength came about as a result of uni-body cars. The mfg's figured out that the "egg shape" was stronger and protected the occupant. Adding glass to that kind of structure required the "welding" or bonding of the glass to the body to keep the integrity of the shape in the event of a crash; add in crumple zones and you create a passenger safety compartment. In essence they are trying to manage the energy from an impact around the passengers.

When car bodies were attached frame rails the energy was managed in a different way.

The point is, is that the mfg's did not rely on the glass for safety until the advent of uni-body cars. Back then cars with rails used a soft sealant between the body, glass and gasket.
Uni-body cars of today that use rubber gaskets are all held in with urethane, body to gasket and gasket to glass. Use the correct priming system and urethane for each application. Ask your adhesive rep about the proper choices.