water for your coolant (long)

["William P. Magliocco" <magliocc@gte.net>]

There has been quite a bit of discourse regarding various types of coolants
for use in Audi/VW engines on the q-list recently.  Allow me to add my
perspective.

I'm not a mechanic, but a d-i-y kind of guy who gets paid to keep one of the
biggest UHF TV transmitters in North America going.  It gobbles up $18k per
month just to keep the local electric utility sending the 480V 3 phase
service to our site.

It has five $30k transmitting tubes called klystrons in the system.  They
are water cooled in what is known as "vapor phase" cooling-around half the
electricity the tube consumes is turned into steam, which is condensed and
then the water is fed back into the tube's boiler system.

The quality of the cooling water is very stringent.  The tube has voltages
of about 25,000 VDC on it, so the water must be pure enough to be an
electrical INSULATOR, which pure water is-start adding minerals, etc. and
your water becomes a very good CONDUCTOR of electricity. Tap water will
simply not do, due to the minerals and such floating around in your local
tap supply.  Our transmitter site is not serviced by municipal water, so
there is a well that often pours out muddy brown "H2O".  This mud is then
run through two 11" cartridge filters taking the mud out to 5 microns, then
through a 5' high carbon cartridge and then two ion-exchange 5' tanks before
it is routed to the four boiler systems in this transmitter.

In other stations, I have seen damage that has been caused by using
poor-quality water in such bolier systems.  That has taught me to use either
steam distilled or process-deionized water when mixing coolant for my car.

All this hub-bub about phosphate free coolant has to do with minerals in
that water you use with the coolant.  If you spend a little time getting
good quality water to mix with your coolant, you should have smooth sailing! 

For those of you that want to try something new, Texaco makes a 50/50 mix of
phosphate-free and deionized water solution that you can buy.  Our
transmitter also uses a 50/50 mix of commercially prepared (UCARtherm)
anti-freeze for our combiner system (which also requires cooling)...we use
UCARtherm (ethelyne glycol) because the OE of some of that system
recommended it.  The 55 gallon barrel came mixed 50/50 straight from the
plant in WV, all I did was to put it into the system.  It was cheaper than
full strength, but a lot more than 27.5 gallons cost at the 55 gallon unit
price...the boss was cheap that week and I didn't want to spend too much
time mixing things.  FTR, UCARtherm would work in a car, but it lacks the
additives car formulations use.

I know some people worry about the chemically agressive nature of the di or
distilled water, but once its mixed with the antifreeze that point is moot.

Sorry for the lecture, all I wanted to say is that the water quality is
every bit as important as the anti-freeze you're buying!

Bill Magliocco
'86 5ktcs
'85 5ks
'86 VW Golf Diesel
'84 VW Quantum & Jetta Turbo Diesel
'85 VW GTI (rust bucket)
'88 VW Fox