Hello Ari,

Better than on the radiator would be to connect a magnesium or other
cathode-protection chunk electrically to the engine block somwhere
immersed
in coolant.  Unless what you're trying to protect is the radiator......

Any ideas on where this can be done without major disassembly?  Also,
are
there any chemist-types who know *for sure* which  sacrificial metal
will
provide the protection desired for this application?

I may be short some of the details, but tinkerers on this list can
probably
figure out a better solution than the 'radcap' as described.

Tom

===============================
>Reply-To: Ari Ollikainen <Ari@OLTECO.COM>
>Sender: Vanagon Mailing List <Vanagon@VANAGON.COM>
>From: Ari Ollikainen <Ari@OLTECO.COM>
>Subject:      Re: head electrolysis cure?
>Comments: To: Vanagon@VANAGON.COM
>To: Vanagon@VANAGON.COM
>
>>Perhaps some dissolved zinc in our coolant would work, being preferred

>>in the red/ox reaction to the aluminum of our heads?  Any chemists or
>>metallurgists out there who could comment on this?  I am not certain
of
>>all the details but I believe the concept is correct...although if it
is
>>wouldn't VW have simply added this "anode" material to the Autobahn
>>coolant to prevent/eliminate the leakage issue and all the irate
>>wasserleaker owners...have changes been made to the coolant since the
>>leakage problem arose?  I suppose that would make regular coolant
>>changes absolutely mandatory to insure that the "anode" material has
not
>>been completed consumed by the reaction.
>
>        It's interesting that this thread would surface at this time...

>        While watching a NASCAR event last Sunday, I didn't pay much
>        attention to the commercial for a new product called "Rad Cap"
>        which purports to provide *exactly* this sort of protection.
>        Unfortunately its form factor (normal radiator cap) is wrong
for
>        the Vanagon cooling system :-(
>
>        Later I saw it again in the MotorTrend October 98 issue "Car
Care"
>        section...see http://www.motortrend.com/oct98/cc/cc_f.html
>
>        A "RAD" SOLUTION TO ALUMINUM EROSION
>
>        The Rad Cap offers an innovative approach to minimizing the
type of
>        internal metallic erosion caused by electrolysis: the stripping
of
>        ions from system metals due to stored electricity in the
cooling
>        system. Based on a concept used in marine applications, the Rad
Cap
>        contains a sacrificial magnesium anode that hangs from the
underside
>        of the cap and is immersed in the coolant. The idea is that
magnesium
>        is a more active metal than aluminum, so it will dissolve
before
>        aluminum, saving wear on the engine's aluminum parts. According
to the
>        company, proof that it works is evident from the fact that the
>        electrical voltage in the solution is usually much higher
around the
>        anode than elsewhere in the coolant. The Rad Cap costs about
$20, and
>        its effective lifespan is estimated at 18-36 months.
>        Contact DD&E, 925/689-6214.
>
>
>
>      OLTECO                    Ari Ollikainen
>      P.O. BOX 3688             Networking Technology and Architecture
>      Stanford, CA              Ari@OLTECO.com
>      94309-3688                415.517.3519

+------------------------------------+
|  CycoActive Products              tel (206) 323-2349
|  701 34th Ave             fax (206) 325-6016
|  Seattle, WA 98122    USA
|  webpage:   http://www.cycoactive.com
|  e-mail:  TomMyers@cycoactive.com
+------------------------------------+