Date:         Wed, 8 Jan 1997 20:03:00 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         mholser@Adobe.COM (Malcolm Holser)
Subject:      Re: Nervous about heads

> Here's what I've been thinking about doing, of course I don't make a move
> without consulting you wonderfull people:)  Since my westfalia tends to
> sit for months at a time, then be used for several months then sit again,
> I thought that I should just drain the coolant out of it altogether while
> it's sitting then refill when I know that I will be using it.  That way no
> corrosion would occur while it's sitting, and I would be sure to change
> the coolant at least once a year.  Of course this will be time consuming
> and probably cause some inconvenience, but nothing compared to BIG BIG
> $$$$ for new heads, or BIG BIG agravation to do the J.B.Weld fix.  So what
> does everyone think??  TIA

Not my bet.  I'd expect good coolant to contain quite a bit of corrosion
inhibitors that wet air would certainly be lacking.  Maybe if you filled
the system with Cosmolene in between...

Use distilled water and clean fresh antifreeze.  One of the prime causes
of corrosion is galvanic action -- where two dissimilar metals in electrical
contact corrode.  This is aided by electrolytes in the water -- even in soft
water.  Pure water is almost a non-conductor of electricity.

Dangling a zinc bar in the coolant, with the bar electrically wired to the
engine would be good if the engine was iron.  That's what ships do to keep
from rusting in the seawater.  I think aluminum is not going to be aided by
such a thing, but my chemistry is years past.

I'd suspect that the corrosion sitting is not the culprit, though.  The other
main accelerator of corrosion is cavitic action -- pressure changes caused
by flow turbulence.  This would only affect the engine while running.  Yet one
more factor in corrosion is the temperature -- cold temps really stop
corrosion -- your car rusts the next summer after driving in all that salt
(that promotes the galvanic corrosion by making water conductive).  I've
seen an aluminum airplane that sat underwater in Lake Michigan for thirty years
that looked better than some VW heads.

malcolm