Lighter Glass

xj220

Founding Member
Sep 15, 2000
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Is it possible to buy lighter glass for our cars? The reason is that the stuff we have is pretty thick and I'm sure it weighs a lot. If so, how much weight do you think could be saved overall?
 
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My 63 falcon squire wagon has a flat rectangle glass rear window. Recently the electric motor fried. It was stuck down. It was snowing. I went to the hardware store and picked up some lexan. At first it felt like plastic. I got some angle aluminum for bracing to keep the glass from flexing and pushing out from the wind. While drilling for rivets, I drilled through the lexan first then through the aluminum, no problem. I eventually switched sides and started drilling through the aluminum first then through the lexan. The lexan cracked when I pushed through the aluminum. It is very small and hasn't gotten worse....yet. I used to think it was easy to work with. I might make my own lexan windows someday, but I'll be more careful next time.
 
Believe it or not this car has Lexan front and back. Pretty good quality.

windshield3th.jpg

Downside...................remove your wipers and use lots and lots of "RainX"

HistoricMustang
www.historicmustang.com
 

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latamud said:
My 63 falcon squire wagon has a flat rectangle glass rear window. Recently the electric motor fried. It was stuck down. It was snowing. I went to the hardware store and picked up some lexan. At first it felt like plastic. I got some angle aluminum for bracing to keep the glass from flexing and pushing out from the wind. While drilling for rivets, I drilled through the lexan first then through the aluminum, no problem. I eventually switched sides and started drilling through the aluminum first then through the lexan. The lexan cracked when I pushed through the aluminum. It is very small and hasn't gotten worse....yet. I used to think it was easy to work with. I might make my own lexan windows someday, but I'll be more careful next time.

Likely, you purchased Plexiglass, not Lexan. All the hardware stores around here carry Plexi, the only place I can get Lexan local is a place that sells plastics or the local circle track speed shop. Lexan is a trade name, like Kleenex, but it's polycarbonate and you can fold it in half. It can crack when drilling, but is usually not very likey. Plexiglass, although it will scratch, is less likely to do so compared to Lexan. You can polish out Plexi easier than Lexan. Lexan will get cloudy from all the tiny scratches eventually. Now there are companies that make Lexan that is coated to make it scratch resistant. But it is very expensive, a full set for a car costs around $1000 and you still have to trim it to fit, but you can go at it with steel wool and it won't scratch. For my '63 Fairlane drag only car, I plan on using Percy's Speedglass. In most states, a non glass front windshield is illegal. In Oklahoma, the rest of the windows being Lexan is legal except the front windshield.
 
Yes, you can get scratch resistant stuff now and $1,000 is cheaper than you could buy replacement galss all around, but, you will have a hell of a time trying to roll a window up or down. It pretty much has to be a permanent installation. You also have to worry about it blowing out of the vehicle if a window is down unless it is screwed or riveted into place. Sealing can also be a problem.
 
Have you considered......

lighter air for your tires? :rlaugh: Safety glass is there for a GOOD REASON. Any weight saving by substituting it would be minimal and the risk would be huge. IU believe that your insurance company would agree.

Originally cars had plate glass in the windows but safety glass became an industry standard in the mid teens. Unless you're talking an all out competition vehicle, stick with safety glass!

If you are REALLY serious about this, consider adapting aircraft grade plastic such as found on a hyper-sonic fighter. You WON'T like the price however. :)
 
Oh I know, I feel safe having .5 in thick glass all around. Essentially I'm just looking for ways to reduce weight, but I don't want to get rid of functionality (like seats or other major interior parts). The best place to start though would probably be the engine since that's where most the weight is and making that area lighter would help balance.
 
Alternate idea

Just removing the spare tire would eliminate more weight than replacing the glass with plastic (and it would cost a WHOLE lot less). Why do you want to reduce the weight? Serious weight reduction cost BIG buckos!
 
HistoricMustang said:
Believe it or not this car has Lexan front and back. Pretty good quality.

windshield3th.jpg

Downside...................remove your wipers and use lots and lots of "RainX"

HistoricMustang
www.historicmustang.com

The rear glass has enough of a curve to it. Did you heat the lexan and form it somehow or leave it flat? Did you use the stock glass rubber? I'd like to see pics of your rear glass if you have them.

Dave
 

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Pathfinder65 said:
The rear glass has enough of a curve to it. Did you heat the lexan and form it somehow or leave it flat? Did you use the stock glass rubber? I'd like to see pics of your rear glass if you have them.

Dave

The front was heat formed by the manufacturer - that is a must to be a good fit. I did the rear here in the shop. They both use standard rubber.

Am headed out for the evening (taking Mrs. HistoricMustang to the theatre - not the movie kind the live acting kind, so see I do have a certain amount of class!) will try to get a photo up tomorrow.

Yes, I think I will have a glass of wine before the play starts...................

HistoricMustang
www.historicmustang.com
 
well, you can have glass custom made but if you think plexi is expensive, custom made glass will give you a heart atack. you can get a pretty good amount of weight savings by going to custom made glass though. the rear window in my 93 cherokee only weighs about 4-5 lbs. but it's so thin it will actually flex when out of the vehicle, it's probably 3/16" or less, it is thin stuff. i thought i was going to break it just trying to get the rubber seal on, much less actually installing it, the side windows are pretty much the same but i think the may be a little bit thicker but still less than 1/4".
 
Those pics are great!:nice: Thanks a bunch. I've stolen them and added them to my vintage racer library:D

So the rear lexan..did you just cut it to the shape of the rear glass and install it allowing it to form itself as it was installed? How thick was the lexan?
Thanks in advance:)

Dave
 
I was reading about these lexan windshields as used in NASCAR and their application for military purposes. The NASCAR lexan windshields are essentially thousands of sheets laminated together. When you get a scratch, you just peel a layer off, revealing a perfectly clean surface. It was like peeling a fruit roll up off a sheet of waxed paper. The army wants to adapt this to Apache helicopters. I am guessing the price is out of reach of the common mustanger for now. As for me, if I wanted to achieve serious weight reductions, I would just get an alum block and carbon fiber hood, door panels, and trunk lid. Fortunately, I am not that stupid. Not yet, at least.