> This said, does anyone know the feasibility of using sacrificial metals on
> the auto body to prevent rusting. Essentially, if one uses a metal with a
> lower emf, you cause rust to attack the sacrificial metal and leave the
> steel body unharmed. This is a practice commonly used on large boats.
>
> I am also considering doing some experimentation with metal powders mixed
> in various rust-retarding paints to determine if rust can be prevented more
> readily. By mixing various metal powders(aluminum, zinc, etc) I may be
> able to create a paint that will prevent rust indefinitely.
>
> Jay
>
Jay,
I can't remember al of my college chemistry, but I think one
requirement for a sacrificial anode is that the two dissimilar metals
need to be immersed in some kind of electrolytic solution, e.g.
seawater. Either that, or the entire surface of the metal to be
protected needs to be in contact with the anode. (This is basically
what galvanized steel is.) I think that's why you see sacrificial
anodes in boats and not cars. If it were as simple as attaching a
zinc anode to the frame, I think we would see more of it from the
factory. On the other hand, modern rustproofing techniques are
pretty good, so there may not be any great incentive for the
automakers to use any additional methods to stretch the life of the
metal parts from 15 years to 20. After all, if they were REALLY
concerned with longevity, all cars would have engine/transmission oil
coolers!
Scott
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