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How much UV gets through glass? Posted by Snowmobile [Email] (#686) [Profile/Gallery] (more from Snowmobile) on Mon, 12 Feb 2018 07:44:51 In Reply to: Re: A crack free dash is overrated......, Notnoel [Profile/Gallery] , Mon, 12 Feb 2018 06:18:35 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Generally glass is fairly absorbing in the UV, especially if there is any tint, as is common on car windows.
I think the bigger factor is visible and near IR sunlight is readily absorbed by the black vinyl covering of the dash which heats rapidly. Under that is a foam core, which is probably fairly insulating and probably heats slower. It would not surprise me at all if they have signficantly different coefficients of thermal expansion, and though both are flexible, thermal cycling over time probably causes them to break down...
That's just my best guess. Maybe it doesn't take much UV to make vinyl brittle, and again it depends on wavelength. The shorter UV wavelengths are generally significantly absorbed by glass.
Aside from perfect restorations, I think there are better solutions (for me anyway) than spending thousands of $$ on a dash. Plus it is a fair bit of effort/time to swap a dash anyway, so I probably wouldn't bother unless I had some other major work to do in the same area at the same time...
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