Hello Chaps,
I used to use distilled water mixed with antifreeze until a chemist
said that de-ionized water is better for this application. He almost
made sense to me when he explained it. Any chemists out here that can
discuss this??? Distilled versus de-ionized water??? (Remember, it
is those ions that carry or permit electric charges, isn’t it??? And
rust/corrision requires an electrical current flow???).
BTW, for years I fought overheating during the summer with A/C on in
my 84S3. Then last summer I had the radiator rodded. The mechanic
said he guessed the radiator was half clogged with anti-leak type
goop. Since then, the coolant temp very rarely goes above the 90 mark
and never approaches the top end. Just wish I had done this years
ago.
Hello Chaps,
I used to use distilled water mixed with antifreeze until a chemist
said that de-ionized water is better for this application. He almost
made sense to me when he explained it. Any chemists out here that can
discuss this??? Distilled versus de-ionized water??? (Remember, it
is those ions that carry or permit electric charges, isn’t it??? And
rust/corrision requires an electrical current flow???).
Check the archives - this topic was debated in depth, breath and height
about 6 months ago. I forget what the conclusion was. I used
deionised, BTW - we have a domestic one in the house, so I have a source
on-tap (literally).
Tom, I agree that de-ionized should be equivalent to distilled – both should
have just H2O molecules in them. De-ionized, hoewever, is prepared by
diffusion of molecules through a membrane, whose microstructure stops
molecules larger than desired and can also segregate charged molecules
(ions). Since H2O fellas are small, essentially uncharged (neutral), it’s a
pretty good approximation of distilling. However, any similarly small,
neutral molecules can get through too – very few like this though.
Since allowed medical uses for de-ionized seem the same as for distilled, we
can probably feel quite safe using either in our cars.
Alex
79xj6
tom graham wrote:
Hello Chaps,
I used to use distilled water mixed with antifreeze until a chemist
said that de-ionized water is better for this application. He almost
made sense to me when he explained it. Any chemists out here that can
discuss this??? Distilled versus de-ionized water??? (Remember, it
is those ions that carry or permit electric charges, isn’t it??? And
rust/corrision requires an electrical current flow???).
[clip]>
Cherio - Tom
I believe that any "distilled "water you buy will say “distilled by the
deionization process” on the label, although I haven’t looked in 10 years.
I was told, when I worked with a pure water specialists company on industrial
pure water applications that I would have to distill water something like 19
times to get water as pure as the deionized water which comes out of a
Barnstead filter (deionized) the first time. Corrosion tho was a serious
problem with DI water.
Mike Moore
63 OTS WIP
Mike, you’re probably right about truly distilled being hard to find, although
I can get it here in a local store. That deionized would be in any way more
corrosive than tap water, would be impossible, however, so we can be confident
in its use in coolant mixtures.
I believe that any "distilled "water you buy will say “distilled by the
deionization process” on the label, although I haven’t looked in 10 years.
I was told, when I worked with a pure water specialists company on industrial
pure water applications that I would have to distill water something like 19
times to get water as pure as the deionized water which comes out of a
Barnstead filter (deionized) the first time. Corrosion tho was a serious
problem with DI water.
Mike Moore
63 OTS WIP
And, someone on the list has their own deionizer, so maybe a cottage industry
for the list could spring up (ooohh), serving us who crave the stuff.On a serious note, remember that chemistry experiments involving water solutions start with distilled, maybe deionized, water rather than tap water for the very reason that you want to know that whatever you’re adding is all that will be in the solution at that point. Also, if you take a DC Ohmmeter and measure the resistance of typical tapwater, it’ll come out to something like 7,000 Ohms (between the clips in a tumbler of the stuff); then do the same for de-ionized/distilled (I got about 70,000 Ohms fro de-ionized) – just did all this. The reason tapwater is 10 times more conductive is that it has 10 times more ions of various sorts able to carry current. In most tapwater, Chlorine counts for much of this – we get Chloramine nowadays in the US, which is supposedly safer than the old Potassium Chlorate. Now these are like salts and can leave deposits and react with metals in any system they occupy for long periods of time, so I do believe that the proper mix of Antifreeze and pure water (distilled or deionized) is best. But, I have to admit I haven’t bothered to use it in most of our cars! Alex 79xj6 “Sean T. McCormick” wrote:
What’s that theory of Homeopathic water remembering healing proprieties?
Give me 4 Gallons. Does Auto-Zone have it?. :-)…Sean
Billy Carter wrote:
The subject of de-ionized water causing more corrosion sounds like Click
and Clack’s theory of “hungry water”.
Regards, Billy
86XJ SIII Daily Driver
Michael, the problem with that logic is that pure water is “hungry for ions”,
which is not what metals in structures are – their atoms are firmly bound by
the electron clouds that define their crystalline structure, which is why
they’re tough and strong. They are not just blobs of ions waiting for water
to suck them up.
To get metal atoms out of these surfaces, we need energy. Acids provide that,
by supplying positive charges (protons from Hydrogen) that are free to remove
some electrons around the metal atoms, allowing them to form bonds with the
other half of an acid’s structure (e.g., Chlorine, Sulphate…). This leads
to, say, Hydrochloric acid combining with Iron to make free Hydrogen and Iron
Chloride (Sulphuric acid will make Iron Sulfate, etc.). Pure water has very
few free Hydrogen ions, so is largely neutral and unaffecting of metals, which
is what measuring a sample’s electrical resistance shows.
Pure water does, as “the almost universal solvent”, have the ability to wrap
itself around lots of different molecules, including ions. And, that’s why
using deionized water is best when desiring to reduce corrosion – various
active ions won’t be present to start the reactions with metal atoms that we
term corrosion. Note that water, when heated to steam, becomes very much more
reactive, because Hydrogen ions start dissociating from Oxygen. Superheated
steam, as in steam-turbine generators is very corrosive, like acid. Other ion
content, as in tap water, just aggravates this corrosive reality. In our
cars, pure water will be quite safe.
Alex
79xj6
“Dr. Michael E. Rothman” wrote:>
The subject of de-ionized water causing more corrosion sounds like Click
and Clack’s theory of “hungry water”.
Regards, Billy
86XJ SIII Daily Driver
Because there are NO ions in the water it leaches the ions out of whatever
metal it is in contact with. The metal seems to disolve or corrode.
Dr.Michael E. Rothman
'87 January build Series III USA
Princess Margaret
On Sat, 20 Nov 1999 00:12:51 -0600 mrothman@megsinet.net (Dr. Michael E.
Rothman) writes:
Because there are NO ions in the water it leaches the ions out of
whatever
metal it is in contact with. The metal seems to disolve or corrode.
%%%%%%%%%%%%%%%%%%%%%%%
This is true if you put only distilled or deionized water into the
cooling system. But what is the chemistry, assuming the glycol is
nonreactive, when you have a solution of distilled water and the
antifreeze additives? With the additivies, I don’t think dissolution of
the metal will occur at a significant rate. I have have wondered about
this for some time but never spent anytime looking for an answer.___________________________________________________________________
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Thomas, the addition of alcohol (to the coolant, not us) simply changes the
specific heat and freezing/boiling points and doesn’t worsen the
corrosiveness. As others have said, the content of Calcium and Silicon salts
is more of a concern, as far as water pump wear and general deposits are
concerned. So it looks like those products claiming to minimize these
additional problems are desirable. I learned that from these discussions, so
will be using distilled water and the improved antifreezes.
Alex
79xj6
Thomas R Schultz wrote:>
On Sat, 20 Nov 1999 00:12:51 -0600 mrothman@megsinet.net (Dr. Michael E.
Rothman) writes:
Because there are NO ions in the water it leaches the ions out of
whatever
metal it is in contact with. The metal seems to disolve or corrode.
%%%%%%%%%%%%%%%%%%%%%%%
This is true if you put only distilled or deionized water into the
cooling system. But what is the chemistry, assuming the glycol is
nonreactive, when you have a solution of distilled water and the
antifreeze additives? With the additivies, I don’t think dissolution of
the metal will occur at a significant rate. I have have wondered about
this for some time but never spent anytime looking for an answer.