I agree with Don that it is low energy not like a heat gun or propane torch
on the window.

Even then, the glass is tempered and will take quite a bit of abuse.
----- Original Message -----
From: "Don" <dkspence@TELUS.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, December 12, 2009 2:31 PM
Subject: Re: Friday question- will this break your window??

> Matt
> The device is meant to be used to "defrost" the rear window.  Frost as
> in ice as in cold as in needs clearing to be able to see through.
> It's not as though you could use it to boil water or melt glass. It
> slowly warms up the filaments and the surrounding glass.  It does not
> "shock" the frost and glass.
>
> Use it for what it was installed to do.
>
> It's -32 C ( - 25.6 F) here today and I would not hesitate to use
> mine, if it would start.  : >
>
> Don
> On 12-Dec-09, at 11:48 AM, Automatic digest processor wrote:
>
> > Date:    Fri, 11 Dec 2009 22:15:27 -0700
> > From:    Bob Stevens <mtbiker62@GMAIL.COM>
> > Subject: Re: [WetWesties] Friday question- will this break your
> > window??
> >
> > They are mis-applying the science. If you were to pour hot water
> > on a very chilled windshield, likely you'd crack it where there are
> > chips.
> > It
> > happens when volks are having their cars worked on and already
> > have a chip or small/short crack. The shop people pull the vehicle
> > into a very warm garage, out of very cold weather, and boing....
> > the crack-runner appears. Happened to a Nissan Pathfinder of mine
> > once long ago. The molecules change size quickly and the weak
> > spot is exposed.
> >
> > bob
> >
> > On Fri, Dec 11, 2009 at 6:36 PM, Rob <becida@comcast.net> wrote:
> >
> >> At  12/11/2009 02:08 PM,Matthew wrote:
> >>
> >> it was around zero degrees f here this week. A coworker claims that
> >>> if i use my rear defrost it will break the rear window? Before i
> >>> call Tom and Ray, will someone chime in??  it seems a bit
> >>> improbable.
> >>>
> >>> thanks
> >>> Skeptic Matt
> >>