SGT

Another reason to get tint!

TimboIS

The glass is in a rubber frame or molding and held with adhesive, so that would have enough play for any expansion. If it were fitted VERY tightly and VERY securly inside a non-flexible frame, then MAYBE your theory may hold true, but it isn't. Don't give up your day job... unless it's a scientist.

ptmIS350

LOL I skipped that day in class on car engineering

duckduck

uhh..I never said the pressure from the AIR in the car cracked the glass. The glass itself could have been unstable/poor quality and cracked on its own. Lexus isn't going to spend $100 dollars on a small piece of window. While I have no clue what the tinter did with the window (take it out and reseal it, or just applied the tint in place), that could have affected it (could have blow torched the tint on the window...who knows )

SportyStar

Another possibility on the case of the blown-out window. An interesting article http://www.protectiveglazing.org/ref...C%20020401.pdf by the International Window Film Association (IWFA), located on the website of the Protective Glazing Council http://www.protectiveglazing.org

According to the article,

"Tinted glass is a major absorber of heat, and leads to a great deal of stress within the glass. Window film (even CLEAR Safety Film), absorbs a certain amount of heat, and if the combined absorption of the window film and tinted glass is very high, this can result in the glass cracking due to thermal stress. This is particularly true for annealed monolithic glass. Dealers should avoid installing films that exhibit an absorption rate exceeding 50% on any tinted annealed glass. Tempered glass that is tinted should generally be safe for applying most solar control films. However, dealers and installers are advised to consult with their respective window film manufacturer before installing films on tinted glass."

Now, whether this actually WAS the cause in this case we don't know ... but I think it's interesting nevertheless ... to do a little research and learn something new. I hope this somewhat addresses Payam's question of whether the heat might have had something to do with it.

duckduck

Ahhh, that's something I didn't know. That would make a lot of sense if the tint absorbed a ton of heat (which would cause a drastic heat flux that would be similar to flash heating/cooling glass...except constantly). You learn something new everyday =)

Payam

Thanks for everyone's help and responces, i'm on my way to Lexus, I'll let you know what happens.

shaolin

iTrader: (2)

so how much did the dealer charge you for the glass?

STIG

I am not an expert on the linear expension stuff but I am pretty sure it's the other way around. Steel expands at nearly twice at the rate of glass. Correct me if i am wrong.


I am sorry to see that happen to your car man. I would be pretty **** if that happens to my car. I feel your pain. Your best bet is to take the car in and call the LEXUS to do the investigation on it. It could be a design error or just assembly (or installation error).

But one thing for sure is that it takes a lot of force to break that small window.

Payam

$309!!!

So I took the car up there this morning and they gave me a G35 to drive around until mine is fixed. He said they would take a look at it and get back to me. They called me around noon and said that it looks like someone tried to break into it through that window. When I told him there was nobody by the car when the alarm went off, he said he talked to some of the other guys there and they all said that someone could have broken the glass earlier and because of the tint, they couldn't get in. And during the course of the day when the car heated up, the glass could have fallen out. I don't know, that sounds kind of fishy to me, but whatever, it's getting fixed. Oh yeah, they also have to order the part in, he said it should be here by Monday.

P.S. The Infiniti G35 doesn't compare to the IS at all!!!!

CaThaFeR

iTrader: (1)

lexus's explanation is exactly what happened on my last car..someone mustve either tried to break in or was being a jerk and broke my drivers door window...alarm never went off or anything and i didnt notice it until the next day when i went to get in the car and saw all the glass was shattered..but was still in tact because of the tint
sucks that such a tiny window costs $309!

Payam

Yeah, but the strange thing is that the window was still in when the guy broke it, and then it fell out later.... I dunno, sounds kind of weird. But oh well...

Kamikaze2b

Wow that's good info, thanks for digging it up!

tqlla3k

iTrader: (1)

What are you going to do about the paint?

Och

iTrader: (3)

Well, the one thing with tempered glass, it can blow out by itself basically out of blue sky, but that usually happens within a few days after its been tempered. When glass is tempered, it aquires internal tension, mollecules on the inner layer are pulling on the molecules on outer layer. In the result, the glass becomes about 4.5 times stronger and it is much harder to break it with a direct hit, however the glass would shatter if you slightly tap it on the corner, and sometimes it can shatter from a deep scratch.

The other thing with tempered glass, is that unlike plain glass it will not break/crack, it will shatter into tiny particles. Tempered glass is used in automobile glass, so that if the glass breaks in an accident, a big chunk of glass wont cut ones head off, instead one would have little pieces of glass sandblast his/her face, get into his/her eyes, stick into his/her skin, but he/she would survive.

Also, glass, and especially tempered glass, doesnt expand much at all. Most glass doors you see in fancy building have 1/8" clearance, and that 1/8" stays consistant all year long. If anything, the flexing of the body panels while driving would cause a lot more stress on the glass than expansion of the glass.

As far as pressure build up in the car - good luck, theres no way in hell it would be sufficient to cause the glass to shatter. For instance a lite of 1/4" Thick tempered glass, about 4 feet x 6 feen can handle about 300psf, and deflect about 3/4" before it would break. If anything, air pressure would cause the rubber/metal frame that houses the glass to fail before the glass would shatter, but the frame seems to be in tact.

It is true that applied film can cause heat build up, but the heat build up would not be sufficient to cause tempered glass to break. Look at cookware, you have temepred glass cookware that you put onto a stove, and it never cracks. However, if you put boiling water into annealed glass glass it will blow up.

Another example is insulating glass units used in curtain walls on high rise buildings. These insulating units consist of two layers of 1/4" glass with 1/2" air space between them, and air-tight perimeter spacer. A lot of times the interior layer of glass has opaque film applied to it so that you can't see into the building from the outside. Imagine all the heat build up from the film and the air pressure build up inside the air tight unit. These units virtually never fail. Imagine the cost of replacing a piece of glass say on the 80th floor of a high rise building? We are talking tens of thousands. So if heat buildup and air pressure build up could cause the glass to shatter, it wouldnt be used on high rise buildings.

Also, if it was the pressure, I would think that it would affect a bigger piece of glass before it would affect a smaller piece of glass.

Also, I dont think that Lexus poorly designed the frame that houses the glass, these frames are very well engineered to allow for the body flex and vibration.

Also, from the pictures you can see that the glass shattered into tiny particles, which means that the glass was properly tempered, and glass quality is not an issue here.

With all that being said, I have come a few theories.

1) Someone tried to break into your car, but that unlikely because to break tempered glass you need to hit it pretty damn hard, preferably with a sharp pont, like a shart rock, etc. That would cause the glass to shatter into the vehicle.

2) Someone tried to pry the glass out, with a knife or screw driver, but when it fell out and made a noise they ran away. This is the most likely scenario. Inspect the frame for any marks that might've been caused by someone prying the glass out.

3) It was caused by the tinter. He might have scratched the glass with his knife when he was cutting the tinting film. Let me explain how glass is cut. If the glass in non tempered, you can cut it with a glass cutter, however it is not cut like lets say plywood or metal. All the glass cutter does is make a tiny scratch on the surface of the glass, and then you press on the glass and it will evenly crack along the scratch. That is NOT the case with tempered glass. You cannot cut tempered glass. If you try and cut tempered glass with glass cutter, it would shatter while you cutting it of when you're pressing on it. Similar thing happens with sandblasting, you can sandblast float glass as much as you want, however tempered glass you can only sandblast slightly, if you sandblast it too deep it will shatter.
So maybe he made a scratch, and it expanded while you were driving, and evetually the glass shattered. However this is also unlikely, because tempered glass is much more scratch resistant than regular glass, and if he was cutting the film with a razor blade, it would be very hard to scratch the glass with it.

4) Highly unlikely, but maybe the tempered glass failed on its own. Sometimes when the glass is tempered, it aquires such great tension that internal cracks occur. Under certain light you can even notice these internal cracks, also called "strain marks". But usually tempering factories check the glass for such strain marks, and usually the glass with strain marks would blow within the first 24 hours. Add to the fact that the glass was installed in a vehicle, and undergoes a lot of flex and vibration during driving, if it was deffective, it would've cracked when the car was rolling of the assembly line.