From: klf@druwa.ATT.COM (FranklinKL)
Newsgroups: rec.autos
Subject: Re: What to do about salt?
Keywords: Bad advice!
Date: 14 Dec 92 19:50:46 GMT
Distribution: rec


In Message: <1992Dec12.153119.27081@tin.monsanto.com>
From: wchutt@alex.monsanto.com (Bill C Hutton) writes:


>With regard to the discussion of when to clean salt from your car. A
>simple rule of thumb would be the colder your car is the less damage the
>salt can do. If you have a heated garage then you should clean the salt
>off ***ALL*** of the time. If you car never comes indoors then very
>little corrosion will occur when until spring when the temperature warms
>up. This is simple reaction kinetics. The worst time for salt damage is
>summer when the temperature is very hot. It is entirely possible that in
>hot weather a trace of salt will do more damage than a lot of salt caked
>all over everything in very cold weather. 
>
>Unless you have a heated garage the most effective way to minimize
>corrosion is to very carefully clean the undercarridge of your vehicle
>when the last freezing weather has passed. I hate to think of someone
>freezing themselves cleaning salt from their car when the corrosive
>reaction is very inefficient due to cold temperatures.
>
>Save your urge to clean and rinse that salt up until you explode in an
>early spring rinsing frenzy.
>
>
>DISCLAIMER: a peronal opinion only
>
>
 And some very BAD ADVICE based on that personal opinion.!

I grew up in Central New York, near Syracuse.  That particular part of the
country gets a lot of cold weather and a mucho snow.  The road department
uses a LOT of salt on the roads.

We lived in a small town and my father drove 50 miles round trip to
work every day for many years.  Our cars were kept in an unheated
barn and were seldom if ever washed during the winter.  Yet by the time they
were a few years old they would all develop rust around the rocker
panels and wheel wells.  Eventually, they would rust through.

The people from my home town whose cars didn't rust were the ones with
the heated garages.  

Actually, the problem is not just the salt.  Granted, salt is corrosive
to steel but the real damage is done by moisture.  Its use in winter is
predicated on the fact that it lowers the freezing point of water, thus
allowing ice to melt at a lower temperature.  That's the key.
When snow and slush mixed with salt get caked up under the fender wells
it forms the well known "fenderbergs".  The salt content will result in
these bergs staying in a "slushy" state at a lower temperature than
if no salt was present.  Now you have not only moisture being held
next to the metal, but SALTY moisture.  A bad combination.
The best bet, if you can't get it washed off right away, is to get the
car somewhere warm where the caked on slush and snow can melt.
The secret here is that salt by itself, causes no problems regardless
of temperature.  However, salt in conjunction with moisture is a
bad combination.

If salt by itself was the problem, how do we account for the fact that
metal items stored for decades in salt mines (where the humidity is very low)
show no corrosion?

--
Ken Franklin 	They say there's a heaven for people who wait
AMA     	And some say it's better but I say it ain't
GWRRA           I'd rather laugh with the sinners than cry with the saints
DoD #0126       The sinners are lots more fun, Y'know only the good die young
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