Corrosion And Corrosion Protection - Mercury Bravo Three Operation & Maintenance Manual

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Corrosion And Corrosion Protection

Whenever two or more dissimilar metals (like those found on the
stern drive) are submerged in a conductive solution, such as saltwa-
ter, polluted water, or water with a high mineral content, a chemical
reaction takes place causing electrical current to flow between met-
als. The electrical current flow causes the metal that is most chemi-
cally active, or anodic, to erode. This is known as galvanic corrosion
and, if not controlled, it will in time cause the need for replacement
of power package components exposed to water.
IMPORTANT: Replace sacrificial anodes if eroded 50% or more.
1
Anodic Plate - serves as a sacrificial anode. Unscrew both at-
taching screws and remove. Install a new anodic plate and tighten
securely.
2
MerCathode System - System should be tested to ensure ade-
quate output.
Test should be made where boat is moored, using Quicksilver Refer-
ence Electrode and Test Meter. Contact your Authorized MerCruiser
Dealer to arrange for this test.
3
Anode Kit (if so equipped) - Mounted to boat transom. Acts as
a sacrificial anode. Replace as required.
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