Greg O wrote:
wrote in message
...

How do I remedy a copper-galvanized corrosion problem on my water
heater connections? I put the water heater in with a friend's help
about 3 years ago. Now please see photos of corrosion between the
flexible copper connectors and the fixed galvanized pipes (both hot
and cold). Photos are at:

http://homepage.smc.edu/morgan_david/corrosion/

Do they sell some kind of spacer that can be put between the two and
is corrosion-neutral or something? What do I want to buy and install
to stop the corrosion? Thank you.


You need to look for a "dielectric union", any home store, hardware store
that sell plumbing will have them,
Greg



Dielectric unions are no good for that application because the tank and
the house pipiing are connected together by code required grounds
already, completing the galvanic cell's connection.

You can get some improvement by using insulated nipples which create a
much longer insulated water path between the copper and steel piping, so
the current density causing the corrosion of the steel parts is reduced
by the current having to flow through a higher resistance water path.

The Rheem water heater company has a technical paper stating this.

http://www.rheem.com/includes/resour...ryPDF/1221.pdf

You'd be far better off replacing all that copper stuff with galvanized
right to the tank, then you won't have any significantly dissimilar
metal joints and no galvanic corrosion problems. Plus, you'd get rid of
a pretty raunchy looking piece of "modern art" there. G

Jeff

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."