Myth or Bust: Tint shatters sun roof

[flossurteeth]

Is it true that tint (say 5% or limo) will cause a sun roof on a car to shatter? If so, why?
Common theories that people have said in car forums:

1) Light and energy during hot days gets trapped inside the sunroof glass, bounces back and forth, and eventually breaks the glass due to the excessive heat retention. (I guess when you keep the shade closed?) In order to help avoid, use silver tint.

2) The sunroof glass expands and contracts from heat and cold. The tint film resists proper contraction and causes the glass to explode.

3) It is caused by nickel sulphide inclusion in tempered windows, not tint

4) Only 2 situations that may cause this to happen:

a) "if it's constructed of a non-glass substance. I've not heard of a non-glass sunroof, but some camaros and firebirds from the 80's had plastic T-tops."

b) "The other is if it is made of laminated glass like a windshield. I've not heard of laminated sunroofs, either, so I doubt that's a problem."
It would be really interesting to hear your opinions and explanations on why or why not the tint will cause a sunroof to break. Thanks everyone!

 

[Drakkith]

How do you know that tint causes the window to shatter? Do you know if there are non-tinted windows that are shattering? The reasons listed so far seem kind of unlikely to be the cause to me.

 

[Nik_2213]

Our car's near-planar sun-roof is tinted and, after 9 years of assorted weather, it is still okay...

( UK doesn't get the sun and heat that eg Arizona might, but you only need one data point to show myth ;- )

FWIW, I've seen a heavily curved windscreen on an old VW Beetle crack without warning.

 

[256bits]

The question is then how many sunroofs shatter without being tinted.
Then you would do a statistical analysis to see if there is any significance to conclude that sunroofs being tinted shatter more than those not tinted.

A lot of car forums seem to just spout out ' here is what I think ... " without any sort of basis of fact. The ones that do know what they are talking about get drowned out by rhetoric.
Your car forum buddies missed out on perhaps it has something to do with the company/ person doing the installaton in an improper manner or application.

 

[pmacias]

I cannot definitively say whether tint will cause a sunroof to shatter or not without proper research and data. However, based on my knowledge of materials and physics, it is unlikely that tint alone would cause a sunroof to shatter.

Firstly, let's address the theories mentioned. The first theory suggests that tint traps heat inside the sunroof, causing it to break. While it is true that tint can absorb heat and cause the interior of a car to become hotter, it is highly unlikely that this heat would be enough to shatter the sunroof. Sunroofs are made of tempered glass, which is designed to withstand high levels of heat and sudden temperature changes. It is also important to note that tint is often applied to the exterior of the glass, so it would not directly trap heat on the inside of the sunroof.

The second theory suggests that tint film resists proper contraction of the sunroof, causing it to explode. This is also unlikely because tint film is flexible and can easily expand and contract with the glass. In fact, tint is often used to prevent glass from breaking due to temperature changes.

The third theory mentions nickel sulphide inclusion in tempered glass as a potential cause of shattering. This is a valid concern as nickel sulphide inclusions can cause tempered glass to spontaneously shatter. However, this is not directly related to tint and can occur in any tempered glass, including sunroofs.

The fourth theory mentions the type of material used for the sunroof. As mentioned earlier, sunroofs are typically made of tempered glass, which is specifically designed to withstand sudden temperature changes. Plastic or laminated sunroofs may be more prone to shattering, but this is not necessarily due to tint.

In conclusion, while there may be some rare instances where tint could contribute to a sunroof shattering, it is unlikely to be the sole cause. More research and data would be needed to definitively determine the cause of sunroof shattering. It is important to properly install and maintain tint and sunroofs to minimize any potential risks.