Red glass lense aging?

[ply33]

On other club forums I have seen discussions about what to do to brighten brake and tail lights. The discussions usually end in talk of higher power light bulbs or replacing the original glass lenses with plastic.<P>I was raised in the desert where one possible hobby was searching abandoned mine and town sites for sun aged antique glass. Sometimes glass that was clear 100 years ago would be found to have aged in the sun to dark colors.<P>This brings to mind the following question: Were the glass tail light lenses of 50 or more years ago always as opaque as we find them now or have they aged to be less transparent?

[Guest]

Tod ~ My family was in the glass business from the late 1800's until I retired in 1990. For years we distributed, among othere products, colored glass for use in stained glass windows and I know of no instance where the glass became more opaque with the passage of time. If that were the case would not church windows have become more opaque with time. Windows have been exposed to constant sunlight. Not an opinion based on scientific knowledge, but I think the density of the color would not darken. <P>Different minerals are used in the "batch" to make different colored glass. Cobalt in blue glass and GOLD in red. The amount used determines the density of the color, so I think some lenses were just made different shades of red. The darker the color the more dense the appearance. I have seen Model T lenses in flea markets so dense that light barely shines through and the one next to it on the table a medium red.<P>I have never seen a clear window turn purple, but there is a 1926 [i think] Flint in Denver with one purple headlight lens. Clear glass cups and dishes found on old slave graves in the South are often shades of purple and it must be from the sun. Perhaps it is the kind of glass, as all glass does not have the same mixture of ingredients. Some types of glass, flint glass for instance, may discolor more than say plate glass. No pun intended, flint is a type of glass used in bottles etc. Flint is also a car with probably headlight lenses made of flint glass. I will stop before I confuse myself. <P>To sum up. I THINK the denser colored lenses were born that way. ~~ hvs

[Guest]

I would believe that many an old bottle or shard of glass found in an old mine was actually not faded due to the sun, but likely due to the contents that had been in it over time.<P>As a younger kid, in the days of yore, I used to sit empty brown bottles of Garrett Snuff onto a fence post and then whack away at rocks with a stick in an effort to bust them off the fence post. Country kids had to make their own play and my Grandmother and uncles had a stockpile of the empty bottles on the farm that was out by the pasture. I learned how to pull in my swing and was pretty good at snappin' the bottles on the first toss after time. Any rate, to get to my point. Many of those old brown bottles were a consistant color of brown when new, but as they aged the color was changed over time, due to the remaining contents of snuff, rainwater that had accumulated into them, bird droppings, etc. It wasn't that the glass had discolored on it's own, but rathar that the contents in the bottle had effected the discoloring over time. I can remember that we occassionally found a cobault blue bottle that was done in the same manner. In the case of the blue bottle, it was likely medicine or chemicals that had been left inside that had reacted over time as the bottle sat out in the hot sun and weather the elements and time.<P>Just the ramblings of a silly old codger, but may explain a bit if your weird enough to understand what was said above in the first place. Ha!<P>Huey<BR> <p>[This message has been edited by coupe1942 (edited 10-05-2000).]

[Guest]

I am familiar with the LUCAS tail lights of the late 40;s and 50;s They did not darken with age but just the opposite. The glass turned from deep red to a faded orange and even sometimes yellow. I have one that fades from dark red to an almost clear.

[palbuick]

I used to sell headlight lenses years ago, for the antique cars.I learned from many people that the old flat glass did fade from sunlight, They went from clear glass to the tinted pink, due to the lead and chemicals in the glass. Many Model T owners wanted the pink lenses, knowledgeable owners would only purchase clear lenses. All this was from experienc and I am not a chemist.<P>Jim Schilf / palbuick

[Guest Hal Davis (MODEL A HAL)]

Is this to imply that many Model T owners are not knowlegable? Just kidding. Couldn't resist.

[Guest]

If Model T owners were actually knowlegable, then why did they name their car with a letter so far down the alphabet? Ha! Ha! Ha!<P>Huey of the other Ford variety (A).