In all these discussions there is something missing. For electrochemical reaction to take place
there must be difference of potentials at 2 diffrent metals or voltage that would drive
ions/electrons. There is none in cooling system. Even if there is, it is microscopic and obviously
will not support electrons flow. Alu alloy of the engine is so well oxidized(that is insulator) that it
surely wouldn't help.
Water can be looked at as weak alcaline solution with OH ions. But any coolant now days has
inhibitors that will neutralize ability of those ions to react with copper. It wouldn't even be
electrochemical aniway.
Leon
85 Subwagen Westy

10/13/01 10:36:15 AM, Larry Alofs <lalofs@ENTERACT.COM> wrote:

>Frank Grunthaner wrote:
>
>> Sorry guys, the water can and will close the circuit. As I said before, the
>> question is only how much and how effective the surfactant package is at
>> reducing the
>> level. Aluminum will corrode, as will the copper. Complex reactions, local
>> chemical variations, oxide formation-insuced changes in potential. Main
>> impact will be slag formation.
>>
>> Answer is corrosion inhibitors in fresh antifreeze.
>>
>> Frank Grunthaner
>
>Yes, corrosion happens.  Certainly different spots on the same piece of metal
>can serve as anodes and cathodes so that redox occurs.
>  I am trying to address the question of whether we *increase* the rate of
>corrosion of aluminum engine parts by using copper in other parts of the
>cooling system ( long pipes, double T, radiator, etc.)  In these cases it seems
>to me that it may be relevant to ask whether there is an electrical path thru
>the chassis.
>  In the classic electrochemical cell ( two different metals in an electrolytic
>solution), there is assumed to be an external electrical connection from one
>electrode to the other.
>
>Larry A.
>
>