AUTOMOTIVE GLASS AND WINDSHIELDS
If you think about it, almost half of your car is made of glass! Glass is an amazing substance. It's not really a solid: it's a supercooled liquid and has many amazing properties. Some are good qualities: It's very hard and resists scratches. It is very transparent and can be tinted. It is very strong and slightly flexible: Glass gets stronger the more stress you put on it!
The down side to glass? IT BREAKS!!! And when it breaks it can be nasty. Glass can cut like a razor. To counter this potential to injure, a lot of the glass in a car is what is known as "Tempered Safety Glass".
The big safety advantage to this is that when the glass finally breaks all that internal stress is released, and the entire piece of glass crumbles into tiny pieces, no bigger than 1/4 inch square. Thus it can't cut you like regular glass, which will break in long, dagger-like shards!!
Most all the glass in a car is Safety Glass: EXCEPT THE WINDSHIELD!!! It is usually a laminated glass: actually 2 layers of glass with a layer of clear plastic in between. The plastic keeps the shards of glass together if the glass should break. There have been a lot of people hurt, disfigured, and killed by going through the windshield, SO WEAR YOUR SEAT BELTS!
Glass is installed in cars several different ways:
MECHANICAL FASTENERS WITH FELT GUIDE TRACKS OR RUBBER SEALS
These are found in windows that open on a vehicle. In door glass, the glass is attached to a mechanism (called a WINDOW REGULATOR) inside the door which pushes the glass up and down. It is normally powered by either a hand crank or electric motor. Some vehicles (vans especially) have hinged windows with a latch and a rubber seal, or sliding windows. All of these use safety glass.
NON-OPENING WINDOWS WITH GASKET
These windows are held in only by a rubber gasket. It surrounds the glass and goes over a metal flange in the window opening of the car body. Often used in the back glass of vehicles, sometimes in the windshields of trucks. This type of window is actually a safety feature: in a collision the glass "pops out", making it unlikely a passenger could "go through the glass" and injure themselves. In this setup the glass provides no structural support to the body.
GLUED IN AUTO GLASS
This is normally found in the windshield and sometimes back glass of vehicles. 2 types of adhesive are used: a "Windshield Kit"and Urethane Adhesive. The old windshield kit stuff comes in a "rope", almost like putty, which you form around the windshield mount area. You then press the glass into it. It provides just enough adhesive force to hold the glass in place. Most older vehicles without a rubber gasket around the windshield use a windshield kit to hold the glass in.
Many newer vehicles use the windshield as part of the structural strength of the vehicle! (Remember: glass is very strong!) This is being done on more and more vehicles to save weight. Urethane adhesive MUST be used in cars where the front glass forms part of the structural strength of the car. Urethane adhesive comes in tubes that fit a caulking gun. It's pretty tenacious stuff. It sticks very strongly to glass and most anything else. Just about all modern windshields are held in with urthane.
WINDSHIELD REPAIR
Most glass should just be replaced when damaged. Most of the time the "comprehensive" part of your auto insurance will pay for the job. For very small "bull's-eye" defects as well as very small "star" cracks in windshields there is another option. Several repair systems exist to inject a liquid acrylic into the defect and repair it. One website making that product is www.gtglass.com . I'm not saying this is as good as a new piece of glass, but if the damage is minor and the windshield is expensive this might be a good option.
SCRATCHES
Scratches on glass CAN be buffed out with rubbing compound, BUT IT'S A LOT OF WORK!!!!
Remember! Glass is VERY HARD!
The Economechanix Cyber Mall
We also serve the surrounding communities of Alachua, High Springs, Hawthorne, and Newberry!
Thank you for visiting the ECONOMECHANIX WEB SITE. Please feel free to comment. We also serve the surrounding communities of Alachua, High Springs, Hawthorne, and Newberry! Gainesville has been my home since 1974, and I've loved Gvl and the Gators since I came here in the fall of 1974 to attend the University of Florida. I loved it so much I stayed and opened my car repair business. Originally it was out of the back of a 1963 Chevrolet wagon, but in 1977 a fellow mechanic and I opened an auto repair shop with actual walls, etc. I stayed in the same location for 26 years, and recently moved my operation to property I bought 15 miles east of Gainesville. I am doing most all the repairs myself now, having reduced my overhead from $1500 per month to practically nothing. I do work by appointment only. I mostly work only on my established customers cars, but I will occasionally take on new clients. E-mail me and I will either make arrangements to look at your car, or I will recommend you to someone who will.
George G. Scott, Jr.