Electronic Leak Testing

[vyv_cox]

How does the new prop differ from the old? Material(s), isolation, rope cutter?

How old is the protective paint on the saildrive? Is it in good condition?

Any change in anode materials or make? (In the past similar problems were due to cheap anodes that were not to standard)

 

[olly_love]

All the same tbh
We lost the old due to a rope around the prop
No cutter and paint is all good

 

[Alex_Blackwood]

So a little investigation today
We have a very small maintained supply but that’s all isolated now, but that’s also been there since 2004!
Checked all connections etc all good
There is 0ma or volts at the engine end when isolator is off
And the keel has nothing bar the keel bolts

few others around us have had the same issue but the serverity is what worries me, it’s eaten 2 button anodes and 1 sail drive

next path is to get the HM to contact all owners around us and see what they have had and if we have anyone new.

it’s all odd asit seems to have happened since we installed the new prop

Where did that curved ball come from?

 

[olly_love]

Not a massive curve ball,

When i took the switch off i found a 0.4ma current through the switch which was for the battery monitoring lights, which are not on when the switch is off

however this doesn't go anywhere near the engine ( so no chance of an earth) and we get 0ma at the engine wires with it all off.

I have asked the HM to email others in the area as its such an extreme case it cant just be a small leak from us causing it

 

[Alex_Blackwood]

Not a massive curve ball,

When i took the switch off i found a 0.4ma current through the switch which was for the battery monitoring lights, which are not on when the switch is off

however this doesn't go anywhere near the engine ( so no chance of an earth) and we get 0ma at the engine wires with it all off.

I have asked the HM to email others in the area as its such an extreme case it cant just be a small leak from us causing it

Hi, Quite agree it is probably not your boat that is causing the problem but something local and adjacent. However I wouldn't , without seeing the situation guarantee that! As a matter of interest, when you say 0.4Ma do you mean point four of a milliamp or four hundred milliamps? Sorry I am not being funny but there would be a difference. One could be the normal circuit current (0.4amps) and the other 0.4Ma could be disregarded. Depends on the circuit.
I hope that you can get a result. I originally said that the problem could be electrolysis but you would need a power supply of some sort for that. From what you say I now think (Could always be wrong) it is probably Cathodic. with your anodes protecting something near by, even if not directly connected.