Rico Sapolich wrote:
>
> In a message dated 2/17/02 12:49:43 PM, developtrust@HOME.COM writes:
>
> << What is the rationale for distilled water. >>
>
> The cooling system requires deionized water.  Although I would think that
> distilled water is also deionized, I slept through too many analytical
> chemistry classes to have any meaningful knowledge of the matter.  I imagine
> that deionized H2O allows the additive components of the antifreeze to
> function as was intended by the chemists' formulation.
>
> Also, deionized H2O is offered by antifreeze manufacturers at inflated prices.
>
> Rich

Distilled, deionized, and demineralized water will all work about the
same for our purposes.  Water can be deionized or demineralized with a
filter.  The ones I use to purify the water for my H. S. chemistry
classes cost about $60 and are good for about 80 gallons.(Chicago water,
YMMV)  Less trouble than operating and cleaning a still.  Distilling is
better at removing organic impurities like benzene, gasoline, etc. but
I'm mainly concerned about the calcium, magnesium, iron, aluminum, etc.
compounds.
  These impurities which give us "hard" water can contribute to deposits
in the cooling system which decrease flow thru the radiator and coat
metal surfaces in the engine decreasing heat transfer.
  When I pulled one of the heads on my 91 about a year ago and saw the
corrosion, pitting, and deposits built up, I started using distilled
water and long life phosphate free Prestone or Havoline.

Larry A.