H42 Anodes question

eianm

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Jul 7, 2010
517
Hunter 42 Sydney
on my 1991 H42 i have anodes on my skeg , shaft and on my variprop. I am intrigued that there is not, and appears to have never been an anode on the keel? My shaft anode is dissolving in less than 2 months, where it used to run 14+ months- same pen, same marina for 10 years and problem only developed in last 12 months. I bought a silver silver anode and took measurements at shaft, engine block, through hulls etc, and got readings all within normal range- re-did all measurements with shore power connected and disconnected- then took the boat out into the bay and repeated all readings- all remained the same, BUT, the shaft anode is still disappearing FAST.
So, any suggestions MORE than welcome- i am now desperate !
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
Just a thought - If you used the Ag reference anode on your boat in your slip but the dock neighbor that might be contributing to your anode problem was either gone, did not have his shorepower hooked up, or piece of equipment running that was allowing the current leak then I think you would get normal readings on your boat. You may have to take several readings on different days. Take an roll call on who is in each time you do your test.
 
Sep 25, 2008
7,077
Alden 50 Sarasota, Florida
....and appears to have never been an anode on the keel?
The keel is lead.

As to the other problem. There is such a thing as too much anode - every anode creates the effect of a battery; the more anodes, the more battery ‘circuits’ you create.
 
  • Helpful
Likes: JamesG161
Dec 25, 2000
5,703
Hunter Passage 42 Shelter Bay, WA
Ever since owning our boat (2002), two heavy zincs on the shaft only. These last twelve months. H42 has no skeg, do you mean shaft strut? Unsure the cause of the issue, but stray electricity coming from some source.
 

eianm

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Jul 7, 2010
517
Hunter 42 Sydney
Found the problem! Had to pay a specialist galvanic corrosion expert to come and find it, but he did right away! The local marine elec had wired up the new galvanic isolator incorrectly- the difference in readings was only some 200Mv but it was enough to have my zincs buzzing! Fingers crossed it is indeed fixed- if i don't post again, consider it fixed!