Silverton 34C, Owner'S Manual

Page: 69 / 212

SYSTEM OPERATIONS-11
A large sacri fi cial zinc anode plate is also
attached to the underwater area of the
transom.
The anodes on the rudder, shaft and trim
tabs are installed by your Silverton Dealer.
The purpose of these sacri
fi cial zinc an-
odes is to attract any destructive electrical
currents away from the metallic underwa-
ter components, thereby preventing their
eventual corrosion and allowing the cor-
rosion of the sacri
fi cial zinc anodes. The
sacri fi cial zinc anodes are considerably
easier and cheaper to replace and their
deterioration will not affect the perfor-
mance of your yacht, as would the deterio-
ration of a propeller or rudder.
The Bonding System is a network of wires
(color coded green) that are connected to
all metallic underwater components within
the interior of the hull, which makes them
one unit for electrical current purposes.
This network of wires is then attached to
the sacri
fi cial zinc anode located on the
transom, which allows corrosion of the an-
ode, but prevents corrosion of the under-
water components.
General maintenance of the Bonding
System consists of yearly replacement
of the sacri
fi cial zinc anode located on
the transom and all other zinc anodes
located on the propeller shafts, rudders,
etc. and should be completed during the
BONDING SYSTEM
The purpose of the Bonding System is to
protect your yacht’s underwater compo-
nents from electrolysis and galvanic corro-
sion. Examples of underwater components
would be the propellers, propeller shafts,
rudders, engine/generator and seawater
intake valves.
Electrolysis and galvanic corrosion occurs
primarily in salt water, but can occur to a
lesser degree in fresh water. Salt water
allows electric current to
fl ow from anodic
to cathodic material. Any two metals from
two components and their relative posi-
tions in the galvanic rating table will deter-
mine which metal loses material (anode)
and which metal remains largely undis-
turbed (cathode). The distance apart on
the galvanic table of the two metals deter-
mines the rate of wear. To help prevent
corrosion, sacri
fi cial zinc anodes are fi tted
to the underwater components of your
yacht, such as the propeller shafts and
rudders.