"Larry" wrote in message
...
"Capt. JG" wrote in news:12m6iaprthtaod8
@corp.supernews.com:

that PVC deprives the metal of oxygen, promotes rust.


Hmm...that's a new one. I thought to make Iron Oxide (rust), you needed
the Oxide part....Oxygen. It doesn't rust if I take that away, like
coating it with paint or grease, right?

Never heard of crevice corrosion Larry?
Stainless steel is stainless because it is covered by a protective oxide
layer (same principle as with aluminum). Oxygen is needed to maintain this
layer. If you cover SS and block oxygen, corrosion occurs when moisture gets
to the SS and in a salt environment, chlorides attack the SS even worse.

Meindert