Shaft anaodes on Sea Rays

20 year old 400 DB slipped in salt 24/7 since new. Never had shaft zincs. No running gear corrosion of any kind.
 
mratlndmrk said:
Our Marina is terrible with stray current. Up until this past season even with 2 per side they were pretty eaten up.
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So, I think this is the most salient rationale. If your boat is in a location that is consuming the specified anodes before one year then additional anode material is probably justified. In looking at the first post, it appears to me that these anodes are not required; three years on them....
 
Also, in a marina that has electrical leakage in the water is a big issue. The marina needs to be held to task to get it cleaned up. The garbage scow that was next to me was eating my boat up; I had my mechanic test the water around my slip then had a discussion with the owners of the marina with respect to potential liability and repairs to my boat if they didn't clean it up. They had that boat next to me out of the marina the next day.
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ttmott said:
Also, in a marina that has electrical leakage in the water is a big issue. The marina needs to be held to task to get it cleaned up. The garbage scow that was next to me was eating my boat up; I had my mechanic test the water around my slip then had a discussion with the owners of the marina with respect to potential liability and repairs to my boat if they didn't clean it up. They had that boat next to me out of the marina the next day.
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Tom - since you are our "steely eyed missile man". is all that is involved in that test is testing the water with a stranded cable (spread out) to a neutral on the boat or pedestal with a voltmeter between the two and looking for "0" volts?
 
@ttmott, I had similar prop damage a few years ago - in freshwater. We get a lot of transient boaters through (public marina) so it was either one of them, or marina leakage. I tie port-to on a T head, and damage was worse on port prop. Of course it could’ve happened on a trip to another marina too. Strange thing to me is current travels very short range in freshwater unlike saltwater. Never did figure it out?
 
carterchapman said:
Tom - since you are our "steely eyed missile man". is all that is involved in that test is testing the water with a stranded cable (spread out) to a neutral on the boat or pedestal with a voltmeter between the two and looking for "0" volts?
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He had a dedicated test unit with a silver anode that he dropped in the water. The other lead was grounded all around the boat's metallic parts, through hulls, rudder shafts, engines, etc. The things that were on one side were "hotter" than the other indicating the boat next to me was the culprit.
 
tc410 said:
@ttmott, I had similar prop damage a few years ago - in freshwater. We get a lot of transient boaters through (public marina) so it was either one of them, or marina leakage. I tie port-to on a T head, and damage was worse on port prop. Of course it could’ve happened on a trip to another marina too. Strange thing to me is current travels very short range in freshwater unlike saltwater. Never did figure it out?
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From my experience it doesn't take long; the damage to my boat was within a year; we were hauling out to rebed the struts and realign all of the running gear. I suppose a lot of variables are in play as to the extent, location, and time the damage occurs.
 
I am a corrosion technician for a natural gas pipeline company for over 30 years, so I know a fair amount about corrosion cells, mitigation on pipelines. I find this corrosion talk about marine corrosion very interesting.
 
tc410 said:
@ttmott, I had similar prop damage a few years ago - in freshwater. We get a lot of transient boaters through (public marina) so it was either one of them, or marina leakage. I tie port-to on a T head, and damage was worse on port prop. Of course it could’ve happened on a trip to another marina too. Strange thing to me is current travels very short range in freshwater unlike saltwater. Never did figure it out?
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In your case I would look within. For example, if the ground or neutral on your shorepower supply is in contact with any of the boat's grounding and bonding you will reap the benefits of a lighter boat (less metal on board). Same goes if your CATV is connected and that coax shield is grounded in the boat. FYI to others, this is only applicable if your boat has an isolation transformer and no galvanic isolators. Jeff - your shorepower ground conductor should only connect to the isolated grounding terminal within the isolation transformer and the white neutral shorepower wire should not be connected to anything; cut and capped.
 
I am not any kind of engineer but given the high costs of props, I am inclined to add zincs to the prop shafts. I was surprised at survey that they were not there but told by broker that searay relies on the one transom and two flat bottom anodes. I am less concerned about them getting loose as it may happen but I have never heard it happen to any of my boatbuddies or myself. Installed correctly they will corrode away long before sliding on the shaft and might not block flow to cutless bearing anymore than the many line cutter designs.
I have read many times wooden boats can be over zinked but less a concern with fiberglass.
I do wonder why Sea Ray choose not to use them but other manufacturers did use them?
 
Thanks @ttmott! That’s what’s crazy here - nothing has been changed or altered since factory, and I only had the issue after one season (3 months in water). I’ve owned the boat 7 years now with only that one issue. I bought the device from boatzincs.com that you plug into an electrical tester but never used it as the problem never reoccurred.
 
tc410 said:
Thanks @ttmott! That’s what’s crazy here - nothing has been changed or altered since factory, and I only had the issue after one season (3 months in water). I’ve owned the boat 7 years now with only that one issue. I bought the device from boatzincs.com that you plug into an electrical tester but never used it as the problem never reoccurred.
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Oh, if it's not continuing and only happened once then I would agree - another boat.
 
Njlarry said:
I am not any kind of engineer but given the high costs of props, I am inclined to add zincs to the prop shafts. I was surprised at survey that they were not there but told by broker that searay relies on the one transom and two flat bottom anodes. I am less concerned about them getting loose as it may happen but I have never heard it happen to any of my boatbuddies or myself. Installed correctly they will corrode away long before sliding on the shaft and might not block flow to cutless bearing anymore than the many line cutter designs.
I have read many times wooden boats can be over zinked but less a concern with fiberglass.
I do wonder why Sea Ray choose not to use them but other manufacturers did use them?
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Many manufacturers have multi segmented shafts or insulated couplings and why they require anodes on shafts. Sea Ray did a great job in their bonding system design, so we really have few problems with galvanic corrosion because of the boat. Unless the boat wasn't maintained well or there is stray current in the water around the boat you should get one year out of the OEM zinc system and never see erosion on underwater metals. I think the anodes are like oil analysis they tell a story and provide a trending over time.
 
So I need ask. Never had inboard. Don’t those anodes on shaft throw them out of balance, especially after they start to wear?
Maybe that why SR don’t recommend?
 
Here's my thinking. I have not put on zincs on my Sundancer 340 because Sea Ray said they are not needed. Boat is 18 years old, never had zincs and shows no sign of pitting on the shafts. First, adding a weight to the shaft changes its balance dynamics by adding modes of vibration at certain speeds. Second, the zinc is almost certainly not going to be itself balanced. I don't think either of these would have a huge effect, but I have a lot of confidence in running the boat the way that the designers designed it.

By the way, some people doubt that the shafts are really bonded because of how the shaft rotates, the clutch, etc. But the Vdrive transmissions have a bonding path designed into them.
 
Angelina said:
Here's my thinking. I have not put on zincs on my Sundancer 340 because Sea Ray said they are not needed. Boat is 18 years old, never had zincs and shows no sign of pitting on the shafts. First, adding a weight to the shaft changes its balance dynamics by adding modes of vibration at certain speeds. Second, the zinc is almost certainly not going to be itself balanced. I don't think either of these would have a huge effect, but I have a lot of confidence in running the boat the way that the designers designed it.

By the way, some people doubt that the shafts are really bonded because of how the shaft rotates, the clutch, etc. But the Vdrive transmissions have a bonding path designed into them.
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Ah no they don't. But by design all of the metal parts are touching each other, sometimes insulated by oil. Not to mention the transmission isn't a straight path either.

If the shaft has wipers on it that are bonded then and only then is it safe to not have "zincs" on your shafts.
 
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