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Old 07-12-2006, 12:38   #16
GreatKetch
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Delmarrey,

The best way to manage emergencies is to avoid them.

Part of your point seems to be that if I don't maintain my boat no system will assure it keeps floating. That is of course true. If you don't maintain, or don't know how to maintain, a system, it will fail in ways that maintained systems will not.

In a way though you have still supported my point about paking glands. The worst case for the packing gland is still not an immediate disaster.

There is one failure point that is in favor of the dripless systems. The catastrophic failure is most likely to occur while the engine is running, and (hopefully) someone is aboard to try to address the issue. If you assume that being aboard a potentially sinking boat is favorable, that is...

Having said all this, there are boats for which dripless systems do make sense, even if you acept all of my comments. Maybe you have a boat with very shallow bilges, where even a small amount of water causes problems. For a boat that is daysailed and never far from help, the worst case isn't that bad. For a boat that spends a long period of time unattended at a mooring or at anchor, a dripless system might also be a good idea, since it is less likely to sink the boat through the "death of a thousand drips".

There is rarely a single "right" answer. I look at things from the perspective of someone imagining my boat halfway through a 3 week passage to the South Pacific. Rags stuffed in a hole in my boat doesn't give me a warm and fuzzy. :-) However, that is not, and should not be, everybody's perspective.

Bill
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Old 07-12-2006, 14:56   #17
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Raven is currently fitted with ye olde fashioned stuffing gland that leaks as you'd expect. Nothing major but being steel the less water inside the hull the better. I've been advised by marine engineer to fit a new gland that is a Volvo product. I've spoken with a stink boat owner mate of mine who has the same thing installed about three months back and he is very impressed with the things performance. His hull is timber so dry is good for him too. I'm not 100% sure of the product name but I'l find out and let you know.

Regards

Andrew
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Old 07-12-2006, 15:29   #18
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I've had nothing but sucess with the PSS.
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Old 07-12-2006, 17:02   #19
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delmarrey, we tried stuffing rags in there. it just leaked more. I finally ended up taking the hose clamps off the two ends, freeing the bushung, and wrapping plastic bags around the bellows, then clamping them in place. Not ideal. but it kept the boat afloat. I was curious,looking at my neighbor's boat. His does not have the water feed. Mine does. It sounds like this is the better design.
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Old 07-12-2006, 17:14   #20
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Scott,
There were two designs, low speed and high speed. PSS has droped the low speed due to problems. The low speed didn't have the port. This was the basis of some of the problems. Owners wouldn't vent the traped air out of them and cause an overheat of the carbon ring. PSS went to the self venting(high speed) style only. Now hey request the vent tube either be run to a presurized water source or run above the water line and left open to atmosphere. Thas allows the traped air a route out and cooling of the carbon ring.
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Old 07-12-2006, 17:52   #21
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I have a PSS shaft seal on my boat, and I'm pretty pleased with it. However, I note that if the engine is not run for a week or so there is a tendency for the the s/s shaft ring to stick to the carbon seal. I think that this is caused by the thin film of water between the mating surfaces evaporating and leaving the salt behind. I have an access hatch in the cockpit floor directly over the shaft seal so if I haven't run the engine for a while I open the hatch, hold the carbon seal in one hand and give the shaft a turn with the other to free it up before starting the engine.
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Old 07-12-2006, 21:33   #22
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Pat, thanks for that. I have the newer version, so I won't stress over it.
Chrisc, that is the exact problem my neighbor had, that caused his failure. His boat sits allot. I will tell him to make that a regular check.
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Old 07-12-2006, 21:49   #23
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Quote:
Originally Posted by Chrisc
I have a PSS shaft seal on my boat, and I'm pretty pleased with it. However, I note that if the engine is not run for a week or so there is a tendency for the the s/s shaft ring to stick to the carbon seal. I think that this is caused by the thin film of water between the mating surfaces evaporating and leaving the salt behind. I have an access hatch in the cockpit floor directly over the shaft seal so if I haven't run the engine for a while I open the hatch, hold the carbon seal in one hand and give the shaft a turn with the other to free it up before starting the engine.
That's good to know. I keep mine on the hard for most of the year so I hadn't noticed. Mine is washed down at the end of every haul out.
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Old 08-12-2006, 10:05   #24
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i agree with delmarrey i purchased our boat in the fall 04 after it was out of the water. had it surveyed and everything checked out ok. in the spring as a course of routine maint. i pulled the strut to have the cutlas bearing replaced andi figured i would have the prop. checked. i backed offthe nuts for the packing nut to replace the the packing as it looked like it had been leaking quite profusely for some time. when i pulled the gland nut back i found the shaft worn with multple grooves. so i had to replace the shaft. came to find out the strut had been bent during a haul out and noone ever realized this. this put the shaft out of alingment so far that it put tnesion on the gland nut and wore away part of the gland nut. this is why there were grooves cut in the shaft. i went with p.s.s. shaft seal. the one thing the co. said was you have to replace the belows at least every 5 yrs. especially if your bats. are located in the area of the bellows because the gassing-off of the bats acid will collect on the bellows and degrade it. mine has a vent tube at the upper belloews collar so there is always water in contact with the seal area. also if you hall the boat and resplash before you start the engine you are supposed to push the bellows back to get the seal surface wet again. if you don't the seal surface will overheat and burn up. you can wet the seal prior to launch by pouring water on it. this is what i do.
regards mike
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Old 08-12-2006, 12:16   #25
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Just to add to what Mike had to say...

Back in the good ole days when working on a swift boat that had broken a shaft. We found the that the packing had been tightened so many times that it had worn a grove in the shaft and that's where it had broken.

I know this was a power boat and the use was extream but it still goes to show ya.........

The nice thing about the PSS is it doesn't wear the shaft. If you need to move the shaft back to do some work you just loosen the set screws, soap up the shaft, and push, no beating on the shaft.

Now if we can only come up with a cutlass bearing that doesn't wear the shaft. How about Teflon® ????
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Old 08-12-2006, 13:06   #26
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I installed an early version of the PSS shaft seal on our boat in 1988. It had a different version of bellows than the current one as it had fewer ridges and it also had a fiberglass(?) cloth covering on it. There was no vent tube. It worked flawlessly for about 7 or 8 years after which it started to leak while we were under power at 6 knots. The bellows had become stiff, and the propeller thrust against the rather flexible motor mounts of the Yanmar were just enough for it to leak profusely unless we backed off to 5 knots, where it would seal perfectly. The boat was in Mexico at the time and I didn't want to pay for a haulout just to replace the bellows, so I took a deep breath and removed the old bellows. The water inflow wasn't that big a deal, and the rule 1000 bilge pump kept the ocean at bay. Replacing the bellows was straightforward and successful inside a half hour. When I adjusted the tension ring to the seal ring, my wife was able to resume breathing!
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Old 25-03-2007, 21:48   #27
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Nice site. very well organized. Iam looking to purchase a catana 48. Anyone out there familar with the design pros and cons ?
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