Flat glass was used from the beginning of American automobile production for protection from the elements until late into the 1960's for some muscle cars.
The history of glass for American Antique, Classic and Muscle car glass is as follows. The original glass was all made clear for all cars the new technology for 1950 year car's was the introduction of GREEN tint glass by PPG at the time trademarked © Solex. Also Many others followed such as Soft-Ray© etc. In 1952 PPG Introduced the ©Solex green tint windshield with a dark blue top shade. Both of these were optional for a few years as clear was still the standard. As the green tint completely replaced the clear glass no real improvements have been done to reduce ultra-violet rays. So if you are restoring for the correct glass of the era I hope this is helpful.
The flat glass of the original cars was not laminated (safety glass).
Automobile safety glass developed along
with the development of side windows in cars. According to
www.Glasslinks.com, during the decade between 1919 and 1929, the
passenger compartment on cars went from being mostly open to having
side windows. Safety glass was first used in cars in 1927. Before
safety glass, windshields could become weapons in an accident when
they shattered on impact like a home window without the safety glass design they only plate glass much like a picture frame glass or home window glass.
How ever laminated safety glass was used for a few years before the switch to tempered glass. The major safety issue with safety glass was it is made of two pieces of glass with a tough film barrier in between the glass so it would not shatter. The problem was with all side glass made with safety laminated glass you could not get out of a damaged car through a window. So along came temper glass. A plate glass toughened with high temperatures. The result is a very durable glass hard to break and if it does it shatters into small pieces that do not produces major injury to passengers.
There are two processes that are used to make tempered glass. For vertical tempering, the glass is held in a vertical position by metal tongs and moved through the furnace. Tong marks are left on the edge and usually cannot be seen if the glass is installed in a frame. Horizontal tempering moves the glass through the furnace on rollers in a horizontal position. This can leave a slight wave caused by the rollers, but it is usually not visible to a casual observer. Horizontal furnaces are the more common method of tempering glass in modern factories.
We hope this is helpful and informative.
