COMMON TYPES OF CORROSION
Galvanic Corrosion
Common type of corrosion caused by dissimilar metals This can occur for a
variety of reasons including dissimilar fittings and fasteners in direct contact
with bare aluminum; or even loose items like sinkers and old hooks that find
their way into the bilge or an inconspicuous area These dissimilar metals cause
galvanic corrosion when immersed together or while in contact with saltwater,
brackish or even contaminated freshwater.
Crevice Corrosion
Lack of oxygen can be another reason why aluminum corrodes Standing
saltwater, brackish, and even contaminated freshwater sitting in the hull of your
boat over a long period of time can cause tiny areas where the oxide layer
slowly gets deteriorated. Not having that natural hard protective coating of oxide
will cause the aluminum to become pitted over time and could potentially evolve
into microscopic pinholes through the hull
Electrolysis Corrosion
When an electrical component in either the AC or DC system is incorrectly
installed or has an electrical fault which leads to ground This fault doesn’t
necessarily need to be on your vessel to cause an issue. It could be located on
a neighboring vessel or a boat on the other side of the marina connected to the
same AC grounding bus on the marina supplied shore power connection These
faults will turn your boat and every other boat in the marina into a battery, with
the saltwater as the conducting electrolyte
Poultice Corrosion
Accumulation of debris can create a highly corrosive condition. Combined with
aluminum, this debris creates an acidic solution called aluminum hydroxide that
can corrode through the parent metal. These areas tend to seriously aggravate
aluminum when there is wet-dry cycling
CORROSION INFORMATION
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Common Types of Corrosion
Galvanic | Crevice | Electrolysis | Poultice
Galvanic Corrosion -
common type of corrosion caused by dissimilar
metals. This can occur for a variety of reasons including dissimilar
fittings and fasteners in direct contact with bare aluminum, or even
loose items like sinkers and old hooks that find their way into the bilge
or an inconspicuous area. These dissimilar metals cause galvanic
corrosion when immersed together or while in contact with saltwater,
brackish or even contaminated freshwater
Crevice Corrosion -
lack of oxygen can be another reason why
aluminum corrodes. Standing saltwater, brackish, and even
contaminated freshwater sitting in the hull of your boat over a long
period of time can cause tiny areas where the oxide layer slowly gets
deteriorated. Not having that natural hard protective coating of oxide
will cause the aluminum to become pitted over time and could
potentially evolve into microscopic pinholes through the hull.
Electrolysis Corrosion -
stray current corrosion is when an electrical
component in either the AC or DC system is incorrectly installed or
has an electrical fault which leads to ground This fault doesn’t
necessarily need to be on your vessel to cause an issue. It can also
be located on a neighbouring vessel or even a boat on the other side
of the marina connected to the same AC grounding bus on the marina
supplied shore power connection These faults will turn your boat and
every other boat in the marina into a huge battery, with the saltwater
becoming the conducting electrolyte
Poultice Corrosion –
accumulation of debris can create a highly
corrosive condition. Combined with aluminum, this debris creates an
acidic solution called aluminum hydroxide that can corrode through
the parent metal. These areas tend to seriously aggravate aluminum
when there is wet-dry cycling
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KINGFISHER BOATS 3125
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3425 OWNERS MANUAL
