Tweet
Originally posted by Strychnine
View Post
-
wtf happened? Did everyone suddenly forget how to make a windshield? I don't remember this ever being an issue before."When the people find that they can vote themselves money, that will herald the end of the republic." -Benjamin Franklin
"A democracy will continue to exist up until the time that voters discover that they can vote themselves generous gifts from the public treasury." -Alexander Fraser Tytler -
Id bet they started mold forming glass rather than heating to bend a flat pane.Originally posted by CJ View Post
Also, the uv crap they put in does odd shit too, throw some polarized glasses on and see the colors."If I asked people what they wanted, they would have said faster horses." - Henry FordComment
-
Did any NHTSA or DOT rules change in the last decade? Could be a byproduct of the glass formation itself (when pouring into mold), or changes in the layering materials, or a new tempering process...Originally posted by CJ View Post
I haven't found much. I'll keep looking for a few min.Comment
-
Yeah I've always noticed that, especially on factory tints, they have like a checker pattern.Originally posted by Baron View Post"When the people find that they can vote themselves money, that will herald the end of the republic." -Benjamin Franklin
"A democracy will continue to exist up until the time that voters discover that they can vote themselves generous gifts from the public treasury." -Alexander Fraser TytlerComment
-
DJ's on the same page. Probably in the initial stages when they're still dealing w/ the liquid --> solid transformation.Comment
-
This, and scratch. My 2012 Focus got a nasty rock chip, spider webbed out to about 2 inches from a pretty small rock. And some sort of debris got trapped by the wiper and put a shallow but noticeable arcing scratch.Originally posted by Buzzo View Post"It is in truth not for glory, nor riches, nor honours that we are fighting, but for freedom - for that alone, which no honest man gives up but with life itself."Comment
-
Seems it's a shape thing and (practically speaking) it's impossible to eliminate it.
Volume 11, Issue 4 - July/August 2009
“But, My Windshield Is Distorted!”
by Russ Corsi
At the advent of bent windshields in the early 1950s, we became aware of a distracting waviness in the glass that quickly became known as distortion.
As the automobile manufacturers began to design more aerodynamic vehicles, glass manufacturers were challenged not only to bend glass to conform to the ”radical” windshield openings, but also to allow the occupants to see through the glass without getting nauseated. A good example of one of the early demanding glass opening designs was on the 1953 Corvette.
Initially, glass quality control managers developed standards that to evaluate manufactured product for acceptability prior to releasing glass to the car companies. As one might expect, the automobile manufacturers didn’t want any distortion, even in the severely bent corners of the windshield. However, the glass companies knew that having no distortion was an impossible requirement to meet.
“As one might expect, the automobile manufacturers didn’t want any distortion, even in the severely bent corners of the windshield. The glass companies knew this was an impossible requirement to meet.”
Evaluating the Glass
OE glass manufacturers soon identified areas of the windshield that should be evaluated. Detailed quality assurance standards were written and presented to the car companies for acceptance. Once accepted by the auto companies, these standards were so specific that most trained quality control technicians would arrive at the same pass/fail conclusion after inspecting the same piece of glass.
Typically, distortion is evaluated against four basic criteria:
1. Cross car distortion;
2. Reflective distortion;
3. Transmitted distortion; and
4. Lower corner distortion.
All four of these standards require an evaluation of the subject windshield from the installation angle that is observed in the vehicle.
• Cross Car Distortion—The windshield is rotated both left and right to a position that allows the observer to look through the windshield (across the car) against a blackboard with both horizontal and vertical white lines that form a grid. The windshield is rotated in both directions to a position where the angle between the grid and horizontal line is 50 degrees. The level of distortion (the grid squares observed develop wavy lines and/or become diamond shaped) observed is compared to photographs that exhibit various levels of distortion that have been approved by the car company manufacturer. It’s important to note that some level of distortion is acceptable.
• Reflective Distortion—Reflective distortion is defined typically as distortion observed on the outside glass surface that is present when viewing the windshield surface, looking at the reflective image on that surface. The windshield manufacturer’s process (bending iron/frame edge support) typically causes this distortion. Windshields are placed at the appropriate installation angle. Wide dark and light strips are suspended above the windshield, parallel to the normal distortion evaluation position. The observer faces the windshield and observes the level of distortion. Acceptance criteria is very subjective. Like the cross car standard, the automobile manufacturers approve limit samples that are used by the glass companies to evaluate their products.
• Transmitted Distortion—A windshield being evaluated for transmitted distortion is also mounted at the installation angle of the windshield in the car. The windshield is observed parallel to the grid board. Each individual windshield pattern is laid out in zones. The most critical zone is located 75 mm from the inner edge of the paint band (zone A). (If a windshield does not have a paint band, this zone starts at 100 mm from the edge of the glass). The balance of the glass that is not covered by the peripheral paint band is in the next zone (zone B). The paint band is zone C while the area of the glass that is covered by mouldings or body panels is zone D. (In many cases, zone C and D can overlap.)
The quality control technician employs a vertical bobbing motion while observing the degree of intensity of the oscillation of the horizontal grid lines. Acceptable levels of distortion are defined for both zones A and B.
• Lower Corner Distortion—After the introduction of larger and larger windshields that are press bent (glass is sagged both top to bottom and side to side), while being installed at more and more severe installation angles, a new type of distortion appeared. It is called lower corner distortion. The technician places his chin approximately 400 mm above the bottom of the windshield. Distortion is then observed against a luminous grid board. As with the other types of distortion, the degree of acceptable distortion has been determined by the car manufacturers with concurrence by the glass companies.
All bent windshields do have some level of distortion. However, acceptable levels of distortion are clearly defined by agreement obtained between the car guys and the glass guys. The A zone of a properly manufactured windshield will appear distortion free to the average driver. However, all non-vision areas will exhibit some level of distortion. (General reference: PPG Industries Automotive Quality Assurance website).
Russ Corsi retired as manager of technical services from PPG Industries’ Automotive Replacement Glass business unit after 31 years in the glass industry. He now serves as a consultant to the industry. Mr. Corsi’s opinions are solely his own and not necessarily those of this magazine.Comment
-
Also, hit up Google Books and browse through Forensic Vision: With Application to Highway Safety.
page 220
Comment
-
What exactly has changed in the last 10 years though? Because it seems to have gotten much, much worse in the last decade, by my observation at least. It seems like they are just lowering QC standards for rejects."When the people find that they can vote themselves money, that will herald the end of the republic." -Benjamin Franklin
"A democracy will continue to exist up until the time that voters discover that they can vote themselves generous gifts from the public treasury." -Alexander Fraser TytlerComment
-
-
Sounds legit.Originally posted by Strychnine View Post"When the people find that they can vote themselves money, that will herald the end of the republic." -Benjamin Franklin
"A democracy will continue to exist up until the time that voters discover that they can vote themselves generous gifts from the public treasury." -Alexander Fraser TytlerComment
-
Go drive a car from the '50s and '60s. They have some crazy distortions in them, with the wraparound windshields and rear windows that bow in/out.
When the government pays, the government controls.Comment
-
They've been doing studies on the effects of cars windshields and permanent eye damage, it is horrible what can happen to a persons eyes, especially with the Corvettes!
Comment
-
Originally posted by CJ View Post
They have become bigger and more aerodynamic. It's one of the reasons most cars made from the late 90s on have 2 different sized wiper blades.Comment
-
I have noticed it for years now although for example I can only see it when sitting at a light and looking across through someone else's windshield from an angle.Comment
Comment