Someone told me that cars manufactured in the UK that have a positive
chassis electrical system, as opposed to negative, do not suffer from
rust.
Is this true? Can anyone there confirm?
Robert Dorset
You may be thinking of differing types of galvanic corrosion or
selective leaching and the effect of various cathodic protection
methods.
The effect can be aggravated by temperature gradients and aqueous
solutions produced in and around the internal combustion engine; for
example; in the mounting joists using poorly selected materials, or in
a widely-braced water cooling system.
As electrical contact to the frame will be made in many places using
dissimilar metals (both not being steel or iron or aluminium), you
could expect a galvanic potential to develop that might be over-ridden
at times, by the correct polarity of normal operating current flow, or
regularly, by the introduction of a sacrificial anode.
As the effect is going to be localized, it will probably be identified
at the early stages of any product's life, and suitable methods of
avoiding it adopted. The automobile is not a product in the early
stages of development, but I can imagine each generation of designers
demanding to know 'why I can't do that'.....
RL