>
> It is common knowledge among those knowledgeable about high purity water
that
> distilled water is almost always more corrosive than tap water. This is
due
> to the lack of ionized metals in it. For example, most tap water
contains,
> among other things, a presence of ionized iron.
As well as calcium and lots of other goodies. If dissolved iron in the water
were good, the cars in Alabama would never have any rust in the cooling
systems because of the high amout of iron in the water.
This "dissolved" iron is
> removed in the distilling process. If the distilled water then comes in
> contact with base iron there is a greater driving force for ionization
> (corrosion) than if the water contained iron ions to begin with.
Electrolytic corrosion takes place not because of the lack of dissolved
iron, but because of the action between dis-similar metals. When the
cooling fluid circulates, a low grade electric current is created. This is
what causes the ions to wander around, corroding your engine and radiator,
etc.
Large trucks, racers, and others use distilled or "soft" water in combo with
the before mentioned sacrificial zinc-magnesium anode. This precludes the
problem with ion transfer of the engine material.
The above also frequently use a coolant filter to remove large bits that
might clog the radiator tubes.
I have used the above combination of distilled water, filter and anode in
multiple collector cars including the unpressurized system types, and late
sports racers. These cooling systems do not exibit any corrosion of the
cooling system components.
I am uncertain about "common knowledge", but I suggest that a lot of folks
who know a lot about automotive cooling systems are doing it as outlined
above. Try it yourself, and you will be plesantly surprised.
Safety Fast!
Ray
39 TB and others
> Deionized water is often even more corrosive than distilled water. This
is
> at least partly due to pickup of acids from the deionizing process.
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