Date: Tue, 24 Feb 2004 17:07:56 GMT From: Bob <uctraingNOSPAMnospamanet.com> Subject: Re: Preventing/repairing dash cracks
On Tue, 24 Feb 2004 13:34:04 +0000, Grunff <grunffnospam.com> wrote: >Sorry, but these products just don't (_can't_) work. For a couple of >reasons: > >[a] To absorb any significant proportion of the incoming UV you need a >much thicker layer than that. > >[b] There's hardly any incoming UV anyway! The vehicle's glass does a >very good job of absorbing 90% of it. Most of the damage is caused by >heat and some is caused by visible light. Grunff: I don't know that I accept your hypothesis on the thickness. Sunscreen for people is not applied in a "thick" layer yet it quite obviously does the job for people. UV protection _can_ be had in thin layers of goo. As to glass absorbing UV - I've researched this in-depth by talking with a professional engineer. Unless the glass is specifically designed for UV deflection and/or absorption, a significant portion (most) of the UV passes right through. There are several components of UV and the nasty ones don't get removed passing through auto glass.