Semi-trivia question

[Guest prs519]

Back in the sixties, I recall finding old cars with laminated flat glass, that the home hobbyist could cut, or have his glassman cut, to replace broken glass. Does anyone know when they first started using the tempered glass? As I recall, all the manufacturers opted to tempered glass at about the same time. Anybody?

[Rusty_OToole]

Early cars used plain plate glass. In most cases this was the windshield, most cars were open cars with no other windows. When closed cars became popular in the twenties, safety glass came in. First car with safety glass was the 1926 Safety Stutz. It had glass with fine wires embedded in it. Later they made laminated glass, 2 thin layers glued together with clear plastic in the middle. This was used by Ford in 1928. In a few years everyone was using it.

I don't know when tempered glass was invented. It was used on side glass and back windows, never windshields (at least in the US). I know they had tempered glass in the 19th century or earlier but the first car maker to use it was Chrysler in 1936.

Edited July 8, 2013 by Rusty_OToole (see edit history)

[Guest Art Anderson]

As noted, laminated safety glass was developed and placed on the market in 1927 (source: Wikipedia) with Ford being the first low-priced automaker to use in in windshields (every Model A was so-equipped), but still used ordinary plate glass in side and rear windows for a few more years. Prior to that, "wired" (wire mesh) safety glass was used in some high-end automobiles for the windshield, it having been developed by Frank Shuman in 1892. Laminated safety glass was invented in France, in 1903 quite by accident by Edouard Benedictus, a french chemist, who discovered a very sticky clear plastic compound that ultimately could be used to bond two layers of plate glass together. Both types of glass apparently were quite expensive back in the day--and the early laminated glass apparently had a tendency to cloud up rather quickly (even the later PVB laminated safety glass as used by Ford (and ultimately just about every other carmaker) starting in 1928 had that problem, as anyone who's ever found and restored a car out of the 1930's and even well into the early 1960's can attest.

Tempered plate glass (also called "toughened glass) is a 1950's development though. My first recollection of that is the Thermopane picture windows and patio doors that became popular in the 1950's. This is the glass that when broken, rather than becoming shards or "spears" of broken glass, crumbles into small "pebble-like" pieces (I helped my dad install four panels of tempered thermopane glass, sized for patio doors, in a large family room addition to our house in the fall of 1959, and one did disintegrate into pebbles one day about 1970, all on its own.

Tempered glass appears to not have become common in cars until the early 1970's, and is, according to all I can find online, used only in side and rear windows, windshields still being laminated, but with tempered glass rather than the older plate glass. the safety aspect is, of course, enhanced by the development of "pop out" windshields (pioneered by Tucker) which greatly reduces the chance of serious lacerations which could be caused by a human head punching a hole in safety plate glass rigidly fixed into a steel frame. It was somewhere in the late 60's or early 70's that Federal regulations mandated the use of pop-out windshields and tempered glass I think.

Art Anderson

[Bleach]

I know for certain the side and rear windows on both my 63 Ford F100 and 63 Dodge Dart had tempered glass. Someone had vandalized both of them in the early in early 80's and I remember quite well the small broken bits of glass that remained.

[john2dameron]

Didn't one of the major U.S. manufacturers have problems with tempered glass disintegrating is some of the first cars they built with compound curved glass in the late 1950"s. Didn't some of them break up when left sitting in the sun?

[Bleach]

Didn't one of the major U.S. manufacturers have problems with tempered glass disintegrating is some of the first cars they built with compound curved glass in the late 1950"s. Didn't some of them break up when left sitting in the sun?

I think some still do that.

[Guest Skyking]

I remember when my father bought his 1955 Buick new it was important on how the car was jacked up, not to crack the front windshield.

[Rusty_OToole]

Curved, tempered back windows were the ones that would sometimes shatter on very hot sunny days. I don't know if it was heat expansion of the glass itself or expansion of the body that stressed the window, perhaps some of both.

[Guest]

As noted, laminated safety glass was developed and placed on the market in 1927 (source: Wikipedia) with Ford being the first low-priced automaker to use in in windshields (every Model A was so-equipped), but still used ordinary plate glass in side and rear windows for a few more years. Prior to that, "wired" (wire mesh) safety glass was used in some high-end automobiles for the windshield, it having been developed by Frank Shuman in 1892. Laminated safety glass was invented in France, in 1903 quite by accident by Edouard Benedictus, a french chemist, who discovered a very sticky clear plastic compound that ultimately could be used to bond two layers of plate glass together. Both types of glass apparently were quite expensive back in the day--and the early laminated glass apparently had a tendency to cloud up rather quickly (even the later PVB laminated safety glass as used by Ford (and ultimately just about every other carmaker) starting in 1928 had that problem, as anyone who's ever found and restored a car out of the 1930's and even well into the early 1960's can attest.

Tempered plate glass (also called "toughened glass) is a 1950's development though. My first recollection of that is the Thermopane picture windows and patio doors that became popular in the 1950's. This is the glass that when broken, rather than becoming shards or "spears" of broken glass, crumbles into small "pebble-like" pieces (I helped my dad install four panels of tempered thermopane glass, sized for patio doors, in a large family room addition to our house in the fall of 1959, and one did disintegrate into pebbles one day about 1970, all on its own.

Tempered glass appears to not have become common in cars until the early 1970's, and is, according to all I can find online, used only in side and rear windows, windshields still being laminated, but with tempered glass rather than the older plate glass. the safety aspect is, of course, enhanced by the development of "pop out" windshields (pioneered by Tucker) which greatly reduces the chance of serious lacerations which could be caused by a human head punching a hole in safety plate glass rigidly fixed into a steel frame. It was somewhere in the late 60's or early 70's that Federal regulations mandated the use of pop-out windshields and tempered glass I think.

Art Anderson

I have a 65 Standard European Beetle that I bought in 68. One week after I bought the car on the way home from a surfing trip I was flagged down by the original owner. Naturally overexcited to see his old car ( he traded it at the local VW dealer for a new one) he proceeded to tell me about how he took delivery hand how different my new to me car was from a export U.S> spec model. He also told me that the factory screwed up by not having all the correct pieces to get through U.S. customs on the car. He explained that the windshield was one of the things that needed to be changed while the car sat in quarantine at the Port of L.A. It seems those European cars used that tempered plate glass from the 40's to at least mid 60's.

[Guest bkazmer]

. It seems those European cars used that tempered plate glass from the 40's to at least mid 60's.

Some French cars still had tempered glass windshields in the 1980's. It is an impressive failure when you take a rock.

[Guest]

. It seems those European cars used that tempered plate glass from the 40's to at least mid 60's.

Some French cars still had tempered glass windshields in the 1980's. It is an impressive failure when you take a rock.

Or when some thief want's to get into your side window of your car. All he has to do is take a few old spark plugs and with a hammer knock off the aluminum oxide ( some people still call it porcelain) and with that in hand just throw it against the window and poof....hardly a sound at all and it's broken.