Posted by Dave on January 21, 2006, 4:13 am
We did this back in college in the 1970's with a friends VW Beetle. The
water refreezes quickly and there is the possibility of cracking the
windows with the rapid change in temperature on the windows.
Posted by Michael R on February 21, 2006, 4:19 am
I've used hot water for 30 years to defrost windows and unfreeze door locks,
and have never had a problem.
Posted by Bill on February 21, 2006, 4:26 am
Have you tried it at -20F?
Posted by Michael R on February 21, 2006, 4:49 am
No, probably 0F was as cold as it got.
There is really not that much difference to pouring hot water on a frozen
windshield compared to cold water on a hot windshield, as when washing a car
in the summer. It's the same temperature difference, and I've never seen a
windshield crack in the summer from cold water either.
And if it is -20F, would you be afraid to turn on your defroster because you
think the 80F air on the inside would crack the glass?
Posted by Bill on February 21, 2006, 4:58 am
Yesterday, at -20F, I threw a glass of water from my second story deck and
only ice hit the ground. At -20F the air that hits my glass initially is
well below zero and gradually warms to the point where it will barely keep
about 90% of my windshield clean. Were I to pour water on my windshield
at -20F it would freeze before I had a chance to switch from the pitcher to
the scraper. I made the mistake of going through the car wash at
approximately -20F and, when I got to my garage, could only open the
passenger side door. At these temperatures, using water to remove ice is
like using gasoline to put out a fire.