Date: Tue, 28 Sep 1999 17:12:38 -0400
Reply-To: Bulley <gmbulley@BULLEY-HEWLETT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bulley <gmbulley@BULLEY-HEWLETT.COM>
Subject: Condensation talk (boring if you want only van news)
Dew is an oft misunderstood phenomenon.
It appears to fall, because, as you observe, it shows up most plentifully
on horizontal surfaces. Dew however, is only condensate, and it will
accumulate to varying degrees on any surfaces that:
a) fall in temperature below the dewpoint
b) have open access to the air
c) have "condensation nuclei" or an irregular surface
(initially, water won't condense on a perfectly smooth surface, as it has
nowhere to condense)
grass accumulates lots of dew because it has all three in abundance, and it
is close to a source of moisture that is usually warmer than the
surrounding air.
Eric and Chris are both correct, dew causes rust. If you have to park
outside, you could (conceivably) run a small electric space heater in your
van. You wouldn't have to keep it toasty warm, just warmer than the
dewpoint by about 10-15 degrees. The extra margin (10-15 degrees) would
probably be enough to conduct through the metal of the van so that the
undercarriage is at least above the dewpoint by a degree or two.
It is STILL raining here in NC. I guess the drought is over here.
G. Matthew Bulley
Director
Bulley-Hewlett & Associates
www.bulley-hewlett.com
Cary, NC USA
888.468.4880 tollfree
-----Original Message-----
From: Mark Gajewski [SMTP:mgajewski@MANVILLERUBBER.COM]
Sent: Tuesday, September 28, 1999 9:58 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Lots of talk about Rust...
This moisture condenses
>and becomes "dew" or water. The advantage this has, to rust your vehicle,
>is that it is on the inside of your vehicle by way of the air. Its
>in places the you cannot get to, after the vehicle was welded together
>from the factory.
I have heard many times that dew will rust out cars....used car dealers
refer to "lot rot" which occurs on cars that just sit on the lot. The dew
collects but without driving the car and getting ventilation around it it
never really dries out and the next night more dew collects. As far as the
vehicle getting wet from dew everywhere air can get to, I'm not so
sure.......I believe the dew only collects on vertical surfaces similar to
rain and then runs down the sides, drips past moving window seals etc.
Just
had breakfast outside this AM and the top of my outdoor table was wet with
dew, but underneath it was dry. The chairs pushed under the table were
also
dry so that's my scientific proof!!
Mark
