Date:         Tue, 4 May 1999 12:04:27 -0400
Reply-To:     Noto-Gaudette <derwin@NET1PLUS.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Noto-Gaudette <derwin@NET1PLUS.COM>
Subject:      Summary-Long Coolant hoses, copper & otherwise
Content-Type: text/plain; charset=us-ascii

Hi all,



Here's a summary of what I've learned since posting to the list a
request for advice concerning the replacement of the long, steel coolant
pipes (engine to radiator & back) that run above the gas tank of our '83
waterboxer. Some info was gained by private responses, other from the
archives. Keep in mind I have no idea what I'm doing w/ a wrench in my
hand, and my chemistry grades were only average ;-) Corrections and
feedback welcomed!



First, a leak is bad news--air in the cooling system = high temps.



Nobody advised me to replace these pipes w/ new VW steel pipes. If you
live in a high-salt area (I do), they'll just rust out again, apparently
from the outside in. Advice from an old post: "A recommendation to
everyone who still have the steel pipes (whole or in part). Sand them
and paint them with "rusty metal primer" (eg. Rustoleum # 7769). This is
a fish-oil based primer which works well on rusted surfaces." Don't

paint your exhaust pipes, though!



Plastic pipes are apparently original equipment for vehicles with a
higher frame number (i.e. VIN #) than mine, even some made in the same
year. I'd like to use these in our van, but one list member writes:
"Apparently the post '86 pipes are plastic, but require a great deal of
extra fitting work and enlarging of the frame openings through which
they pass." Another claims "you need to buy a set of new rubber hoses to
convert." Any more on this, anyone?



Common, successful approaches: High quality replacement rubber hoses,
such as those made by Gates. They aren't cheap, but are apparently a
better value than VW's offerings. Also good: Radiator/Heater hoses, 1"
inside diameter, w/steel (not plastic) reducer/adaptors, 10' at about
$1.30 U.S. a foot. Even better, if you can find a marine store, 1-1/2"
ID.



One person used super - duper - heavy - duty truck coolant hoses, and
they're apparently really, really stiff & hard to work with. Several
people suggested PVC--cheap but brittle when cold, can balloon when
hot--even hot water PVC is inadequate, according to one detractor. Other
suggestions: Rubber water hoses (6,000 miles w/no problem) and stainless
steel (an untested hypothesis).



Now the hard part--copper:



Several people have used copper pipes, apparently to their great
satisfaction, although I've found no long-term evaluations yet. Such
pipes are commonly used on trucks, are cheap & easy to work with, and
last a looooong time. It's important that they be mounted softly
(between rubber), as copper fatigues.



However, several people have warned that adding copper to the cooling
system can increase corrosion of the aluminum parts in the engine,
including (of course) the heads. This was discussed in some detail by
people who speak Chemistry a while back. As I understand the exchange,
two dissimilar metals (i.e. steel and aluminum, and, even more so,
copper and aluminum) connected in the presence of acid is the very
definition of a battery, which amounts to corrosion of apocalyptic
proportions. But one can make sure one's coolant is alkyl and doesn't
contain salt (that is, doesn't contain phosphates) to prevent this
(small) electric current from being generated.



It gets trickier: Apparently separating the metal parts negates the
"battery" effect (another reason to mount the copper between
rubber!)--if I understand correctly, this is why a "sacrifucial anode"
(a metal piece designed to do all the corroding for the cooling system)
wouldn't work to protect your engine unless it was located, say, in the
water jacket (also, the anode would have to be made of something more
reactive than aluminum). Here's how one listee put it: "Copper radiator
and/or copper pipe pieces in the cooling system: Unless explicitly
grounded these are typically connected through rubber hoses (and the
radiator is mounted with rubber mounts), so there is no direct current
path between the copper components and the aluminum head. Hence only
little/slow corrosion is likely."



So...if I understand correctly, what you'd have worry about with a
properly installed set of copper pipes would be only slightly increased
corrosion risk. This should be easily manageable with good coolant
change/flush habits. But then, I don't really understand all this--for
more chemistry, see these archive links:


http://gerry.vanagon.com/cgi-bin/wa.exe?A2=ind9901C&L=vanagon&D=0&P=18612


http://gerry.vanagon.com/cgi-bin/wa.exe?A2=ind9901C&L=vanagon&D=0&P=19545





I'm still looking for responses from those who installed copper years
ago. I'll let you know when I know.



Best of luck!



George & Christine Gaudette

Fitchburg, MA

1983-1/2 Westy