Testing Procedure For Corrosion Protection; Corrosion Symptoms - Mercury BRAVO Service Manual

SERVICE MANUAL NUMBER 28

Testing Procedure for Corrosion Protection

1. Unplug shore power (if equipped).
2. Measure hull potential with silver/silver chloride reference electrode and digital volt/ohm
READINGS

CORROSION SYMPTOMS

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•
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90-863160 MAY 2000
meter.
Saltwater
Freshwater
Paint blistering (usually on sharp edges)
Loosely adhering white corrosion products on exposed aluminum surfaces (do not
confuse these with tenaciously clinging calcium carbonate deposits)
Aluminum pitting
Potential
Below 850 millivolts
Between 850 - 1100
millivolts
Above 1100 millivolts
Potential
Below 750 millivolts
Between 750 - 1050
millivolts
Above 1050 millivolts
TROUBLESHOOTING
Diagnosis
Drive is corroding.
(Refer to "Drive Corroding")
Drive is protected
Drive is overprotected.
(Refer to "Drive Corroding")
Diagnosis
Drive is corroding.
(Refer to "Drive Corroding")
Drive is protected
Drive is overprotected.
(Refer to "Drive Corroding")
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