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Discussion Starter · #1 ·
Hi All,

I currently looking at a used Tartan (26yrs old) and have a few hangups, the first BIG one being that propeller shaft is corroded between the engine and the stuffing box and saltwater has given it that bright blue hue. Could be caused by lack of maintenance on the stuffing box, or the engine is out of alignment.

Now I've seen what saltwater does to metals and usually at this stage I would think the shaft is compromised and certainly not capable of a long voyage without the risk of more damage/failure, however I'm wondering if something like this be salvaged or if it needs to be replaced.

Here are the photos of the shaft from inside the boat and outside the boat. It looks fantastic from the outside and like new which is weird. But the inside is a nightmare. AFAIK this shaft is one piece (direct drive) so would need haul-out to remove and replace. And might even need to drop the rudder but would need measurements as the engine is mounted more towards the middle of the boat to be certain.

Outside of calling a Marine mechanic (which would be my next move) curious if anyone here has done this procedure, the cost, and know what might be involved with a job this size. Anyway here are the photos:

https://drive.google.com/folderview?id=0Bx6tzmnoism-M245cmprMGZMblk&usp=sharing
 

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That blue color, verdigris, is not an indication of a problem. That can happen to copper alloys simply out in the air. Can be polished off if you like. I would leave it. Doesn't mean there isn't some other problem though.

Related comment: Replacing prop shafts is a normal thing on boats. You need to expect this kind of work if you are messing about in boats. Also, a haul-out is not actually required to replace most prop shafts, but it sure helps.
 

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Discussion Starter · #3 ·
That blue color, verdigris, is not an indication of a problem. That can happen to copper alloys simply out in the air. Can be polished off if you like. I would leave it. Doesn't mean there isn't some other problem though.

Related comment: Replacing prop shafts is a normal thing on boats. You need to expect this kind of work if you are messing about in boats. Also, a haul-out is not actually required to replace most prop shafts, but it sure helps.
I knew the "blue stuff" had a name. And reassuring that it's not an obvious sign of potential failure. Very helpful thanks.
 

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Over Hill Sailing Club
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Probably just surface oxidation but if it looks like it's "peeling" in layers, it could be the sign of electrolytic corrosion, a more serious problem. That shaft log needs some serious cleaning up as do the flange bolts. If you ever need to adjust the packing or get the shaft disconnected to realign, etc., it will be a task. Better to do mechanical stuff like this ahead of time. Maybe replace the flange bolts and nuts and put some anti-seize on em when reinstalling.
 

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Looks pretty normal for a bronze shaft. it can be keep a little cleaner but hard to reach and out of sight of mind. what you do not want to see is pink color on the bronze. with the packing leaking a little water ( it should be dripping when turing ) it is hard to keep them from corroding. change to a stainless steel shaft and a dripless seal and it will stay a little cleaner. its only money.
 

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Discussion Starter · #7 ·
That shaft log needs some serious cleaning up as do the flange bolts. If you ever need to adjust the packing or get the shaft disconnected to realign, etc., it will be a task. ...Maybe replace the flange bolts and nuts and put some anti-seize on em when reinstalling.
Good thoughts. The flange is quite rusted, and shaft does look flaky. Always hard to judge unless in-person. these were photos from the broker.
 

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Does that hose have 10/75 written on it? 40 years in service?
 

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One of None
Hunter 34
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Maybe look at newer boats? What size and area are you looking for? New shaft, seal, cutlass bearing are expected expenses, not a BIG problem. Wasabout engine? anything else?
 

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I think it should be cleaned up, not for esthetic reasons, but to see if there is an issue with the metal. If it has started to leach out zinc, it will turn a pinkish shade. You can't tell unless you clean it up. Granted it would be more likely to happen under the water line, but it may well have been sitting in a wet bilge, perhaps with a wire in the water leaking current into it.
 

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Tartan 27' owner
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Tartan 30'? Which model Tartan?

I would think some bronze wool with a bit of water would clean up the patina/verdegris. If it is stubborn I might try a little vinegar (light acid) making sure to flush it off the metal afterwards.

We replaced the bronze shaft on my Tartan 27' some years ago, plus put in a new Cutless bearing.
From memory, the new SS shaft was about $300 or less.
New Cutless, about $60.
New packing, zinc, face&fit of the flange added a little more.
Materials for the job did not cost more than $600.
We did the labor.

Bronze stuffing boxes can last a very long time. We reused our existing one.
2011, November 30th. Begin drive train rebuild | Odalisque
 

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Caleb's numbers for parts are about right - maybe even a little high. The big question is do you need to drop the rudder and what is the labor cost if you are not going to do it yourself. I would guess you could wait until the next planned haulout and do it then.
 

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Bombay Explorer 44
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Caleb's numbers for parts are about right - maybe even a little high. The big question is do you need to drop the rudder and what is the labor cost if you are not going to do it yourself. I would guess you could wait until the next planned haulout and do it then.
+ 1

Even then look hard at it before you replace it.

If it ain't broke don't fix it!
 

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I think it should be cleaned up, not for esthetic reasons, but to see if there is an issue with the metal. If it has started to leach out zinc, it will turn a pinkish shade. You can't tell unless you clean it up. Granted it would be more likely to happen under the water line, but it may well have been sitting in a wet bilge, perhaps with a wire in the water leaking current into it.
The green color of the 'verdigris' is from copper that used to be part of the shaft ... quite a slow process but over a very long time there will be significant 'transfer' of the copper into a mixture of copper acetate and copper oxide.
Best is to remove the verdigris, and spray on several coats of a clear urethane, etc. -IMO

The other statement of 'don't fix until its broken' is a damn good one. Bronze shafts often seize solid in steel or iron couplings, many time requiring the shaft to be cut free. The replacement cost can be 'high', especially if the replacement was unnecessary.
 
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