Right on Gary.
there are even 'sacrificial anode' radiator caps out in the non-vanagon
world.
( and since diesel vanagons use a very common type of radiator cap ...one
might even fit a DV )

In boats they  call them 'zincs' ..
Like a plate of zinc bolted to the rudder - a sacrificial anode.  Replace it
every few years.

The coolant filter is a great idea too !
and it wouldn't be too hard to make a device that just goes inline in a
coolant hose, with an anode in it, or ideally, the two combined, filter and
replaceable anode, in one device.

Scott
----- Original Message -----
From: "Gary Bawden" <goldfieldgary@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, May 06, 2010 10:12 AM
Subject: Re: stainless steel coolant pipes

> This issue keeps coming up - - why not just install a coolant filter
> as used on commercial and industrial engines, they contain a
> sacrificial anode (magnesium, I think). Can't hurt, might give a
> feeling of reassurance to those who imagine their coolant passages,
> radiators, etc., rotting away mile by mile. :^)
>
> Gary
>
>>
>> Date:    Thu, 6 May 2010 06:08:21 -0700
>> From:    Don Hanson <dhanson928@GMAIL.COM>
>> Subject: Re: stainless steel coolant pipes
>>
>> On Thu, May 6, 2010 at 4:35 AM, Andrew Grebneff <goose1047@gmail.com>
>> wrote:
>>
>>> On Thu, May 6, 2010 at 11:25 PM, Ken Wilford <kenwilfy@comcast.net>
>>> wrote:
>>>
>>> > OK, let's think about this in a logical manner.  The original 1.9l
>>> Vanagons
>>> > had plain steel pipes.  The piston liners inside the engine are cast
>>> > iron
>>> > with steel studs holding the heads on.  Any way you look at it the van
>>> > is
>>> a
>>> > multi-metal soup.
>>> >
>>>
>>> ...hence the head-corrosion problem?
>>>
>>> I guess it doesn't really make any difference which antifreeze you use,
>>> so
>>> long as you actually use the stuff.
>>>
>>> --
>>> Regards
>>> Andrew Grebneff
>>>
>>
>> That is exactly why the heads do leak on this era German water-pumper
>> engines..  Heat+ dissimilar metals+a conductive solution to connect it
>> all
>> together=a recipe for corrosion.  The 993 Porsche motors have the same
>> problems as a WBX.  Change away with your antifreeze/coolant mix...your
>> motor is still attacking itself.still it is probably the best thing to
>> keep
>> the fresh coolant in there.
>>
>>   I wonder if anyone has ever experimented with installing  sacrificial
>> anodes like are used in the marine world?  A couple of small bits of zinc
>> somewhere accessible in the coolant circulation system might mitigate the
>> corrosion problems you WBX owners encounter in the head area?
>>
>>   Don Hanson
>>
>> ------------------------------