Shaft anaodes on Sea Rays

dtfeld

dtfeld

Water Contrails
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Jun 5, 2016
5,625
Milton, GA
Boat Info
410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
Engines
Cat 3126 V-Drives
I've been told that Sea ray did not put anodes on the shafts of their inboard boats, something about not necessary. However, there were anodes on my shafts when I bought the boat and I replaced them when I last had the boat out of the water.

I'm in fresh water, but there was a good amount of material eaten away on the removed anodes. This is a picture of the shaft anodes after 3 seasons in fresh water. In my mind there is enough material missing to justify having shaft anodes.

What is everybody else doing?

20211227_174723.jpg
 
My boat had shaft zincs when I bought it and I have continued for the past 14 years. FW told me he didn't use them on his boat.
 
The Bill Collector said:
My boat had shaft zincs when I bought it and I have continued for the past 14 years. FW told me he didn't use them on his boat.
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I haven't checked but, I wonder how the shaft and props are bonded/protected?

I don't have shaft brushes...
 
Look at your shaft coupling. Is there an insulated vibration block between them?

If yes the shaft and prop are electrically free floating. Otherwise there is going to be some bonding thru the gears and shafts in the trans.

I would use the anodes cheap protection.
 
Never had them on any boat in the Great Lakes, but I put them on while coming down the River system for use in salt when we looped. When I hired a diver to clean the bottom in Ft Myers, he took them off without asking, when I asked him what was up with that, he said Sea Ray doesn’t recommend them. He was a very experienced diver. I then researched it and found out he was right, Sea Ray doesn’t recommend it. I didn’t put any on for subsequent trips south.
 
I'd like to know why they don't recommend...as in official documentation on SR letter head...and not from the marketing Dept.
 
Seems like about 50/50 on using anodes. Something is eating them...better the anode than the props/shafts.

As far as I can tell, it seems like cheap insurance even with the possibility of them sliding down and covering the cutless.
 
People are funny for sure, out west here in CA everyone runs anodes, Zinc in Salt, Aluminum in Fresh or brackish water. I guess everyone figures it is cheap insurance with little concern for the downside. The PO had three anodes installed on my 506 shafts, my engines are bonded as well but I have no idea what Carver recommended or delivered their boats with but I put two anodes per shaft back on after the bottom job at the time of purchase. I think since the anodes do corrode the thinking is that they are offering protection. Not so sure the actual science would support that, but once people have their minds set it's hard to convince them otherwise. I think also they see how the engine anodes deteriorate and everyone stresses the importance of maintaining them, so they extend that thinking to the shaft anodes.
Carpe Diem
 
dtfeld said:
Seems like about 50/50 on using anodes. Something is eating them...better the anode than the props/shafts.

As far as I can tell, it seems like cheap insurance even with the possibility of them sliding down and covering the cutless.
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If changed yearly and installed correctly, there is very minimal chance they'd slide down. I change mine yearly and no issues. Very cheap insurance and I'd rather the anodes wear versus anything else...
 
I do not use zincs on my 390 in salt water. I have bonding brushes instead and the brushes are there only because I installed "Drive Savers" several years ago. Before the Drive savers were installed I did not use shaft zincs. I also have water cooled Tides shaft seals that eliminates the need for the "squared style" zincs you see mounted way up near the shaft logs on some inboards. The squared style zincs are there to "push" cooling sea water up into the shaft logs to prevent overheating.
 
There are problems with too many anodes also; Surveyors call it "over zincing". Indications are pitting, blistering, and flaking of copper-based bottom paint. It would take a lot of anodes, I think, to cause this situation on a fiberglass hull.
Around the macerator dump through-hull on my 400DA the bottom paint was falling off around that port for 18 or so inches; it looked burned actually (no it's not the Frank's Hot Sauce). During a haul out for insurance survey I had the surveyor look at it; he said it was a case of too much zinc on the boat but that it was extremely rare on fiberglass boats. I had no more or less zinc on the boat than what SR originally designed. To this day I don't know the real cause but that is where I became aware of too much anodic protection.
Tom
 
I read; I think on the Yacht Forum, that there is a specific target percentage of anode to underwater metal which is in the 3 to 5 % range I believe. I think that was in reference to surface area. I was not interested enough to get out a tape and calculator to figure out exactly what my boat has in the water. I took a wander through the yard and took a look at similar boats with similar under water gear and used that as a gauge. I did not see any boats running three 2 1/2-inch shaft anodes. I think the PO had cut back on the diver schedule and had additional anodes installed to make up for it. Also he was in a known 'Hot' marina in SF.
Carpe Diem
 
My boat has never had shaft zincs since new and has zero issues in fresh water
 
We purchased our boat from a dealer that took it in on trade. At the time of survey there were no zincs on the shafts. Not sure if the PO used them but surveyer pointed out wastage on the prop nuts. The dealer added shaft zincs due to this and I’ve used them since. This season when I hauled 1 zinc did slide down and was up agains the cutlass bearing. So question is was the wastage due to lack of zincs? Note this was on one side only.
 
And for those that do install zincs on the trim tabs Bennett advise to only install them on the top of the tab. Installing them on the bottom disturbs the flow of water over the surface of the tab and makes them less effective.
 
I have never seen a Sea Ray boat with a failed shaft due to internal galvanic corrosion, period.
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No but there are external issues that any given marina may have. The attached pic was from my first year with my Sea Ray. I now use 2 per side (although this year there was hardly any degradation).
 

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mratlndmrk said:
No but there are external issues that any given marina may have. The attached pic was from my first year with my Sea Ray. I now use 2 per side (although this year there was hardly any degradation).
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I've been told by several people now that 2 per shaft is over zincing them...
 
We run 1 per shaft on The Office
Saltwater
Monthly dives for cleaning, with
zincs inspected and replaced as needed.
When we got to Savannah and arranged the first dive, one of our zincs had dropped off somewhere between Cape Fear and there. They were replaced. In the last 15mo they have been replaced once. My divers will leave the old ones on my dock box for me to inspect.

No additions, just maintaining it the way it came (to me).
 
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