Demo & Cases
Interpretation of results
Searching for electrical leaks
Corrosive electrical leaks make corrosion potential measurements go upwards or downwards, according to polarity. Successive switching of onboard electrical means and equipments thus allows instant detection of possible corresponding failures. Similarly, these measurements must not vary while shore power is plugged or unplugged.
Sensors and kits
Measurement on steel or aluminium hull and S-drive or propeller shaft. Value must show between (-) 1100 mV and (-) 850 mV for an efficient cathodic protection. If it moves significantly while switching on equipments or while plugin in shore power, there is a leak to the sea directly linked to the test...
- GRP Hull 42' - Aluminium sail-drive.
- Fast destruction of sail-drive due to piercing pitting.
- Potential measured within under-protection range.
- Involves a screw from electric panel, getting through 2 cables, causing a leak to the sea. Should measurement have been made just after work, leak would have been identified at once...
- Aluminium hull 32' - Antifouling paint.
- Blistering and disbonding of underwater paint system after complete renovation, including sandblasting.
- Potential measured well inside over-protection range.
- Wrong anodes material suspected. These turned out to be magnesium, strictly prohibited in sea water...
- GRP 38' - Rudder stock.
- Pronounced localized corrosion on rudder stock.
- Potential measured as nominal in all configurations.
- Corrosion being stabilized, implementation of preventive solutions...