On Wed, 12 Nov 1997, James Charles Ruwaldt wrote:
> This is probably a primary reason, but don't positively grounded cars have
> a tendency to rust more than negatively grounded cars? Whether this is a
> significant reason in the switch to negative ground, I don't know, but
> what is the reason for this tendency to rust more? I suspect that it may
> be that the body and frame maintain a positive charge, while oxygen ions
> are negative, thus encouraging the oxidation of the iron, which is, of
> course, rusting. Negatively grounded cars have a negative charge and
> repel the oxygen ions. Can anyone tell me if this is a correct
> assumption? I realize we're getting out of electricity/physics and into
Actually, you're still in physics. And chemistry :-)
In order for the car to attract/repel charged ions, the car itself must be
charged. ...with static electricity.
This would mean you'd be able to put a strap from the car to the ground
(as in, 'dirt'), and electricity would flow through the strap (don't ask
which way; it depends)
Static does build up in your car, and grounding it may/may not help. I do
not think it has anything to do with the way a battery is hooked up. I
know if you carry a fuzzy pet with you, then a ground strap may help, but
pets rarely cause rust-- incontinent ones aside. I'm also pretty sure that
that on foggy days, static is less of a problem (water droplets
dissipate the electricity)
Now, if the car was constantly immersed in salt water, then you might have
something there. Boats have a zinc plate (or similar object) whose sole
purpose is to oxidize (by electrolysis?) and thus stop everything else
from rusting. However it is difficult to enjoy a submarine car, you can't
go very fast and they're hard to put gas into.
As alway,s I could be wrong.
-Malcolm
|