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Myth or Bust: Tint shatters sun roof

  1. May 9, 2012 #1
    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!
    Last edited: May 9, 2012
  2. jcsd
  3. May 9, 2012 #2


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    Staff: Mentor

    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.
  4. May 9, 2012 #3
    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.
  5. May 9, 2012 #4


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    Gold Member

    The queston 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.
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