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-   -   Propeller Shaft Log (http://www.sailnet.com/forums/c30/94237-propeller-shaft-log.html)

Philzy3985 11-19-2012 11:38 AM

Propeller Shaft Log
 
When I bought my boat, 1985 C30, a few months ago the surveyor noted this:

""Recommend adjusting propeller shaft log flax nut to allow for one "drip" of sea water every 30 seconds while engine is running. Minimize to one "drip" every 12-15 minutes while engine is off.""

So I live on my boat, and I can see the bilge stays at about 1/3 to 1/2 full.. and the auto bilge pump kicks on about once an hour (Seems too often to me). Common sense tells me to slowly tighten the nut (engine is off) until the dripping goes down to once every 12-15 minutes.

I've looked and noticed that the access to this nut is awful. The floor in the galley has a panel, but the nut is forward more. Maybe I can get to it by taking my drawers out and going through the bottom of that space.

Anyways. The least desirable thing is to re-do the flax, but it doesn't seem to difficult.

Any suggestions, anyone have the same experience and it was simple fix?

..Just don't want to come home to my boat underwater at the slip one night..

SlowButSteady 11-19-2012 12:32 PM

Re: Propeller Shaft Log
 
Stuffing boxes rarely catastrophically fail. The drip-drip-drip may get faster over time, but it's very unlikely to just start gushing water. That said, having the bilge pump cycle once and hour is indicative that too much water is getting into the boat. If you aren't going to take the boat out for a few days, I would tighten the nut until the drips completely stop, pump the bilge, and wait and see if water is getting into the boat via some other route. If the pump doesn't cycle any more (give it a day or so), adjust the nut to something resembling your surveyor's recommendations. If it does keep cycling, start looking around for another leak.

Also, make sure the hose that connects the stuffing box to the shaft log is in good shape and is properly clamped; four clamps, two on each end. Leaks from that hose or its connections are often unnoticed, as the access to such is even worse that of the stuffing box itself.

jameswilson29 11-19-2012 12:40 PM

Re: Propeller Shaft Log
 
You might also consider installing as second automatic bilge pump, as recommended by Boat/US for a boat your size.

If the water in the bilge bothers you, you could also convert to a PSS dripless shaft seal.

SlowButSteady 11-19-2012 12:48 PM

Re: Propeller Shaft Log
 
Quote:

Originally Posted by jameswilson29 (Post 950458)
You might also consider installing as second automatic bilge pump, as recommended by Boat/US for a boat your size...

Not a bad idea. I would also put a cycle counter (like this) on every automatic BP you have.

Quote:

Originally Posted by jameswilson29 (Post 950458)
...If the water in the bilge bothers you, you could also convert to a PSS dripless shaft seal.

Those can, and sometimes DO, catastrophically fail.

GaryHLucas 11-19-2012 06:11 PM

Propeller Shaft Log
 
I would not tighten the packing more than once without the shaft running in between. Shafts often are no longer perfectly round and you could easily overtighten without realizing it.

Philzy3985 11-19-2012 07:42 PM

Re: Propeller Shaft Log
 
Thanks everyone those are good suggestions. I'm going to tighten the nut a little tonight. Empty out the bilge and see how quickly it fills again by tomorrow. Then going away for a week so hopefully the auto bilge does its job.

Is it possible that from one-time to another of motoring, it will leak more or less? It seemed fine after one sail trip, then worse after another, then back to leaking less, now leaking more. I hope this is the only leak. The boat was hauled out a month ago for bottom paint and the cutlass bearing replaced, nothing else alarmed the fellows at the yard.

CalebD 11-19-2012 10:09 PM

Re: Propeller Shaft Log
 
Quote:

Originally Posted by Philzy3985 (Post 950697)
...
The boat was hauled out a month ago for bottom paint and the cutlass bearing replaced, nothing else alarmed the fellows at the yard.

If the yard replaced the Cutless bearing, did they also re-pack the stuffing box at that time?

With new stuffing there is always a bit of a "break in" period where you may have to adjust the packing nuts a bit for the best setting, fewest drips.

If the packing was not replaced then keep tightening it a little at a time. I think that re-packing a stuffing box is a 10 year maintenance item (unless it fails first!).

Philzy3985 11-19-2012 10:33 PM

Re: Propeller Shaft Log
 
They did not replace or do anything to the flax or stuffing box when it was out for the cutlass bearing.

a guy in the yard pushed on the propeller shaft and commented "might be loose" but that was it.

I took a look tonight and I'm almost certain its the 27 year old original nuts. All covered with greeb/blue crusty corrosion. Oh yeah, and pouring water. Like a faucet 20% on... Much more than drips..

There's 1 boat yard in my marina so ill walk over there at 730am when the open tomorrow. Get some insight and quotes. See if they want to haul ot out or do it in the water at their dock.

There's no way I could tighten or loosen the nuts. Lack of big enough tools but primarily its all stuck like a rock. The water is coming in the bottom behind the nut and onto the shaft. Between the nut and transmission is where its dripping down from.. Er, uh Leaking down from.

Hopefully some pros can fix it before I head out of town Wed afternoon and I don't have to worry anymore. Bilge pump is turning on once every 30 - 45 minutes for a couple seconds.

CalebD 11-19-2012 11:09 PM

Re: Propeller Shaft Log
 
Stuffing boxes do not usually fail catastrophically but if you don't know when it was last re-done and it is warning you now (eg., not dripping but pouring) it is time to replace the packing. Packing is cheap, ~ $25.
Start spraying a penetrant like PB Blaster, or ATF on the nuts now and allow to it sit for a while, days even. The nuts will move eventually with the right tools and lubrication.

A very temporary fix would be to stem the leak from where the shaft exits the boat on the outside (underwater) using candle wax, Butly tape or whatever works.

G'luck.

Philzy3985 11-26-2012 12:33 PM

Re: Propeller Shaft Log
 
Update and I hope final statements to close this story:

The boat was pulled out of the water, and the stuffing box replaced with new hose, new hose clamps, and they made it longer to tighten down on a fresh part of the propeller shaft. Stating that the propeller shaft was a little warped and worn out where the last fastening was. New packing and packing nut. And, finally, a much dryer bilge. It was sort of an emergency for my piece of mind because I was heading out of town, and didn't want to think about that auto bilge pump fighting a leak for 5 days straight. At least I know it's new and been gone through, and I can clean up my bilge and start "fresh".

This time it was a $550 piece of mind. Most of that being the haul out and labor.

Thanks for your input everyone.


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