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23-08-2013, 12:53
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#1
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Registered User
Join Date: Aug 2013
Location: Yardley, Pa
Boat: Sea Ray Sundancer 39'
Posts: 6
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New "Big" boat owner
Hello all - first post here. I'm about to take possession of a 1991 Sea Ray 350 Sundancer. and I have a boat load of questions . This is my first boat with inboard engines.
The drippless shaft seals leak (quite impressively) at higher RPM (no leak at low or idle RPM). I don't know yet what brand they are or if they can be adjusted to stop leaking. The questions I have are:
1. Why are they SO expensive?
2. Which brands are best? (I like the PSS seal)
3. Can the seals be replaced while the boat is in the water?
4. Will I be able to insure the boat without fixing the seals?
I think I'll limit this discussion to the shaft seals for now.
Thanks,
Tom
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23-08-2013, 13:54
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#2
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Registered User
Join Date: Feb 2013
Location: Bumping around the Caribbean
Boat: Valiant 40
Posts: 4,625
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Re: New "Big" boat owner
1. Not exactly sure.
2. PSS is the brand that most people mention, and seems to have a good rep.
3. It is probably "possible" if you have a big enough pump, some serious balls, and have previous experience doing the work. The job will be infinitely easier (and most likely much better done) with the boat hauled. The shaft should be pulled and checked, and might require machining for the new seal. I can't imagine that you'll find a professional mechanic who would agree to do it with the boat in the water.
4. If it's been surveyed, then the leaking seals were (hopefully) flagged as a priority safety/structural/CG regs issue by the surveyor. The insurance company will require you to remediate any of those items within a certain period and to sign a document confirming that the work has been done.
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23-08-2013, 14:19
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#3
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CF Adviser
Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
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Re: New "Big" boat owner
With the new graphite braided packing material, I'm surprised that people are still enamored of drippless technologies. Why buy something that will soon wear out, and could sink your boat when it fails?
Graphite packing glands are the way to go.
Welcome to the forum, by the way.
__________________
cruising is entirely about showing up--in boat shoes.
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23-08-2013, 14:21
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#4
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Registered User
Join Date: Aug 2013
Location: Yardley, Pa
Boat: Sea Ray Sundancer 39'
Posts: 6
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Re: New "Big" boat owner
Bash,
Please tell me more - I know nothing about stuffing boxes.....
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23-08-2013, 15:25
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#5
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Senior Cruiser
Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 16,306
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Re: New "Big" boat owner
Quote:
Originally Posted by CruiserTom
Bash,
Please tell me more - I know nothing about stuffing boxes.....
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Here is a link to a web site by forum member Maine Sail that shows pictures and instructions that will show you all about the traditional stuffing box.
Re-Packing A Traditional Stuffing Box Photo Gallery by Compass Marine at pbase.com
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
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24-08-2013, 07:53
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#6
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Registered User
Join Date: Aug 2012
Location: Maryland, USA
Boat: 58' Sedan Bridge
Posts: 5,420
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Re: New "Big" boat owner
Quote:
Originally Posted by CruiserTom
Hello all - first post here. I'm about to take possession of a 1991 Sea Ray 350 Sundancer. and I have a boat load of questions . This is my first boat with inboard engines.
The drippless shaft seals leak (quite impressively) at higher RPM (no leak at low or idle RPM). I don't know yet what brand they are or if they can be adjusted to stop leaking. The questions I have are:
1. Why are they SO expensive?
2. Which brands are best? (I like the PSS seal)
3. Can the seals be replaced while the boat is in the water?
4. Will I be able to insure the boat without fixing the seals?
I think I'll limit this discussion to the shaft seals for now.
Thanks,
Tom
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It might not be the seals leaking, but rather the hoses that inject cooling water to the seals. IOW, might just need some tightening, new clamps, whatever.
PSS and Tides and the most common makes; both seem to have a good rep. The ones that are "best" might be the ones you already own
ONE of those (TIDES) is usually installed with a new lip seal already on the shaft. The old lip seal can be removed and the new lip seal slid down into place while in the water.
See manufacturer's websites.
-Chris
__________________
Chesapeake Bay, USA.
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24-08-2013, 08:40
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#7
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Registered User
Join Date: Feb 2008
Posts: 375
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Re: New "Big" boat owner
You can easily tighten the PSS seal (ie squeeze bellows in direction of stern). Unless totally worn or some other problem (eg shaft alignment) this should stop leakage. It takes a few hours run time to "polish" the carbon face seal. Despite the concerns about sinking boats, very many vessels have these types of seals. I have not heard of them (I expect someone to come up with those I missed!!) actually failing and sinking a boat.
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24-08-2013, 09:04
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#8
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Registered User
Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,483
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Re: New "Big" boat owner
Quote:
Originally Posted by Bash
With the new graphite braided packing material, I'm surprised that people are still enamored of drippless technologies. Why buy something that will soon wear out, and could sink your boat when it fails?
Graphite packing glands are the way to go.
Welcome to the forum, by the way.
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Yeah, why spend big bucks when a $3 item will work. Seems like I've seen as many posts about dripless seal issues as packing issues on this forum.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard
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24-08-2013, 09:09
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#9
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Registered User
Join Date: Feb 2008
Posts: 375
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Re: New "Big" boat owner
But if your boat was not built with a stuffing box, you are stuffed!!!
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24-08-2013, 12:06
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#10
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Registered User
Join Date: Aug 2013
Location: Yardley, Pa
Boat: Sea Ray Sundancer 39'
Posts: 6
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Re: New "Big" boat owner
Propeller shafts can't be retrofitted with a stuffing box??? I can't see why not.
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24-08-2013, 15:01
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#11
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Senior Cruiser
Join Date: Oct 2007
Location: 29° 49.16’ N 82° 25.82’ W
Boat: Pearson 422
Posts: 16,306
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Re: New "Big" boat owner
Quote:
Originally Posted by CruiserTom
Propeller shafts can't be retrofitted with a stuffing box??? I can't see why not.
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I don't either. As long as there is a shaft log with a provision for attaching the stuffing box hose which I think even dripless seals use (guessing since I don't have a dripless seal), then it's a straightforward change. It will require hauling the boat and pulling the prop shaft out.
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
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25-08-2013, 07:30
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#12
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Registered User
Join Date: Jun 2013
Location: Seattle WA
Boat: Roughwater, pilot house, 58 ft
Posts: 485
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Re: New "Big" boat owner
They are suppost to leak a bit under way to lub between the color a.d the bellows. also as the rpm of the engine increasez so does the raw water flow and pressure. You can increase the pressure against the bellow by moving the ss collar back. If the water leak is coming from under around the collar you could wrap emergency tape around the shaft and collar you. There probably is nothing major wrong with the dripples. As long as it does not drip when the engines running and or shaft turning.
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25-08-2013, 07:47
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#13
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Moderator
Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,764
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Re: New "Big" boat owner
Quote:
Originally Posted by chrisjs
You can easily tighten the PSS seal (ie squeeze bellows in direction of stern). Unless totally worn or some other problem (eg shaft alignment) this should stop leakage. It takes a few hours run time to "polish" the carbon face seal. Despite the concerns about sinking boats, very many vessels have these types of seals. I have not heard of them (I expect someone to come up with those I missed!!) actually failing and sinking a boat.
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As the owner of a 12 year old PSS shaft seal, I was also concerned to read this.
I've never heard of boats being sunk by them. Is there a catastrophic failure mode?
I had mine inspected while my boat was out of the water for a refit last winter. The engineer said the seal was fine with plenty of life left. Nevertheless, I wonder whether I'm pushing my luck.
It doesn't leak a drop and has never given me the slightest trouble. It is one of those which is pressurized with sea water from the raw water circuit of the main engine.
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25-08-2013, 07:52
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#14
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Moderator
Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,764
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Re: New "Big" boat owner
Answering my own question: Dripless Shaft Seals | PassageMaker
Fairly sobering stuff. I think I'll just replace mine entirely this winter.
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25-08-2013, 07:56
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#15
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Registered User
Join Date: Feb 2008
Posts: 375
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Re: New "Big" boat owner
Perhaps I was unclear. I was not suggesting that boats had sunk - just the opposite!!
I have a PSS from 1999, that was replaced as routine preventative service in 2008. At that time PSS recommended replacing the rubber every 6 years or so - I think that has changed. There was no indication whatever of deterioration in the mechanical seal or the rubber bellows on the removed unti. The new unit is fine after 5 years and I have no intent of doing another preventative replacement in the near future. I will add that we have a slow turning trawler prop., so perhaps with high speed props. the maintenance may be more critical. But again, I think the stories about major failures are hyped and the result of inadequate attention by owners. I will also add that our PSS is "locked" in place witha large shaft zinc to prevent the unit relaxing/sliding back along the shaft and leaking. This should be routine when installing these units.
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