I'm not a chemist or metalurgist, but I did have an aluminmum boat that I used for several years in salt water. The process your talking about is called electrolosis and occurs when two disimilar metals with greatly different electrovalences are pressed together. What happens is a battery is formed and one metal looses electrons to the other causing corrosion. With aluminum and steel the steel looses electrons to the aluminum causing corrosion between the metals basically locking them together with rust from the steel. If this were to occur in a salt water environment, with the salt water facilitating the chemical reaction it occurs very quickly as I soon discovered with my boat.
The grease and oil used in the hook should act as at least a partial insulator greatly slowing down in chemical reaction between the two metal, though I have no doudt that if an aluminum shim were left in place for say 20 or 30 years some corrosion would occur.
Steve
Last edited by Rockdoc; 11/03/06 12:24 AM.
