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      12-02-2012, 10:49 AM   #10
Second Lieutenant

Drives: '12 135i MT LeMans
Join Date: Nov 2012
Location: Ottawa, Canada

iTrader: (0)

Originally Posted by Artmasterx View Post
I think that saying salt is acidic is not correct, and there is no need to "neutralize" it. It is not alkaline either.

Salt obviously does indeed increase rates of corrosion, but not because it is acidic, and more to do with increasing the rate electron transfer and ion transfer in the water. Since the rusting or oxidation process involves ion and electron transfer, salt increases the rate of oxidation.

I just don't want people going into their kitchen and mixing up solutions of baking soda or sodium hydroxide and spraying it on the undercarriage and thinking it will mitigate rusting.

The main ways to minimize corrosion/rust are to:
- keep things dry
- keep oxygen away
- reduce exposure to salts (this won't prevent corrosion, but will slow it down)
- reduce time exposed to water/oxygen/salt (cleaning)

If you can't do these things (clearly you can't with a car undercarriage), then coatings or non-rusting alloys may be the best option.

Cleaning and protecting is obviously important, and I think that was your main point.

I just want to make sure I understand this correctly.

In this part of Canada they use road salt heavily in winter, sometimes it looks green maybe its the other chemicals added to it.

Are you saying that if I go to a spray wash in winter (what I've been doing on average once a week on my VW for the past few years)

This is bad because it will accelerate the corrosion process? I guess I was given poor advice, I thought the goal was to wash off all the salt right away and to not let it sit on the car for long periods. It seems like it may be better to have the salt sit there if its cold enough and rinse it off less often? A lot of the roads here look "wet" even during sub freezing temperatures...

What steps can I take to slow down or prevent as best as possible rust from forming prematurely? I don't have access to a lift or these undercar paints/sprays.