"Ralph Hertle" wrote in message
...

Rust prevention method:

This may be more than is needed, however, ......

Steel piping and structural steel beams may be effectively protected from
rust where there is air and water, high humidity, or water condensation
present by means of a block of zinc metal that is soldered or screwed to
the steel.

The gas company might take a dim view of you screwing or soldering onto the
gas line.
Gas distribution (and all other underground pipeline companies) companies
spend considerable time/money on cathodic protection. Small amounts of
electricity is run through pipelines, whenever a new service, or main
extension, or any other significant addition or subtraction is made to the
piping system they will take readings between the pipe and adjacent damp
soil, and add large cathodic blocks as needed to bring the readings into
their allowable range.

JTMcC.



Zinc blocks function as a part of an electric circuit in water.
the water on the surface completes the circuit. Instead of the oxygen in
the air or water combining with the steel it combines with the zinc metal.
Harmless zinc oxide powder is formed as the zinc is corroded away. The
steel remains un-rusted.

The zinc may be attached with a stainless steel screw to the steel, and
the
zinc-to-steel contact patch must be clean metal to metal. The zinc and a
small patch of steel around or near to the zinc is left bare metal.

Zinc is used on auto body panels and on steel hull boats or boats that
have
steel parts, e.g., prop shafts, that are in the water. The zinc blocks are
replaced from time to time.

Purchase the zinc blocks and fasteners from any boat accessory or boat
engine supply store. Several shapes are offered, e.g., disks or blocks.

Notice that anti-rust primer paints contain zinc. In water and oxygen when
the zinc in the paint is used up the finish will fail and rusting will
occur. A coating that totally seals the steel surfaces from water and
oxygen will prevent the establishment of the electric circuit and rusting.
Other metals will work, e.g., window frame aluminum in contact with steel,
and the aluminum will be the sacrificial metal. Check the electromotive
series in a chemistry book for a list of the metals that will work and
that
will not work. Use the wrong metal and the steel will be sacrificed by
means of more rapid rusting.

Ralph Hertle