Corrosion Protection - Monterey 180 FS Owner's Manual

Chapter 7

CORROSION PROTECTION

Galvanic Corrosion
Galvanic corrosion (electrolysis), is the break-up of metals due to the effects
of electrolytic action. When two dissimilar metals are immersed in a
conductive fluid such as salt water, an electric current is produced, much
like a battery. As the current flows, it takes with it tiny bits of the softer metal.
If not stopped, a great deal of damage could occur.
If you operate in salt, polluted, or brackish waters, your boat should be
equipped with a transom mounted zinc anode to prevent damage to those
metal parts coming in contact with the water. By design, the anode is self-
sacrificing. It is slowly eroded away by electrolytic action and requires peri-
odic inspection for deterioration. If the zinc shows extreme erosion, it must
be replaced for continued protection.
Most engines are equipped with one or more zinc anodes which must also
be inspected regularly for deterioration. Some boat models may be
equipped with an electronic cathode system. This system emits a low
current electrical charge into the water close to the metal components. This
charge cancels the effect of electrolysis.
Never paint or coat zinc anodes or cathodes with any sub-
stance. Once covered, they do not provide protection from
galvanic corrosion. Replace anodes if they have deteriorated
50% or more.
Salt Water Corrosion
The entire boat should be rinsed with fresh water and washed immediately
after use in salt water. If the boat is used primarily in salt water, wax the hull
monthly and apply corrosion inhibitor to all hardware. See your dealer for
products suitable for the marine salt water environment. Fresh water
internal flushing is recommended when used in salt, polluted, or brackish
waters. Flush the entire engine cooling system with fresh water for at least 5
minutes after use in these waters. See your dealer for appropriate flushing
devices.
7-4
CAUTION