Re: OXIDATION OF STEEL WOOL-SALT WATER vs. TAP WATER?

Dear Michele;

For the iron to rust "Oxidize" there must be both water and oxygen present. 

In pure water with no air present, iron reacts with water only very slowly. 
In dry air, it also rusts very slowly. In the California desert, I have 
seen tin cans still shiny after several years exposure. 

The presence of salt in the water would speed up the reactions of air and 
water with the iron since the salt water will conduct electricity much 
better than plain tap water. Since the oxidation of iron [in fact,nearly 
all corrosion] is an electrochemical reaction this would aid in the passage 
of electrons.  But, where the iron is covered with water, the access to air 
is minimized, so rusting is slow.

You may have observed that the rusting appeared mostly at or just below the 
water level.

Repeat this test with the steel wool only partly submerged in the salt 
water, it may rust faster.

I am forwarding to you directly via eMail a response I made to a similar 
query a few weeks ago. I hope it will answer some of your questions.
 
                      Charlie Crutchfield