Dripless Stuffing Box Help

[Pete7]

Perhaps I should start a thread along the lines of:

"Whats the best wax polish for engine room GRP and bilge surfaces"

Afterall doesn't everyone have nice clean dry bilges



Pete

[Uncle Buck]

Thanks to everyone for your help. It is a Tides, though the two yards I have contacted recommend replacing it with the PSS set up (which seems ok if backed up with a collar/zinc as suggested in the other thread). It would make sense to me I should just be able to replace the seal rather than the whole unit if I stick with what I have? I have them looking into this option.

[Pete the Cat]

As a former delivery skipper I used to have a surcharge for folks with these PSS "dripless" units. I spent more time in port fixing these units and the damage they caused than weather or diesel malfunction delays. I have no idea why people use them as there are now shaft seal seal (the black stuff) material that renders these old hat. Put it in an old style stuffing box and hand tighten it with this packing and you will not have any problems--no heat, no scoring and no drips. The boatyards love the PSS dripless as they provide substantial income to install and repeatedly fix. They do not use dripless seals in nuclear submarines nor do they use flax that drips. Think about it....We have waited several decades for this new solution and it is finally here. I have used it in my own boat for the last 3 years. Perfect.

[Extemporaneous]

Originally Posted by Pete the Cat

As a former delivery skipper I used to have a surcharge for folks with these PSS "dripless" units. I spent more time in port fixing these units and the damage they caused than weather or diesel malfunction delays. I have no idea why people use them as there are now shaft seal seal (the black stuff) material that renders these old hat. Put it in an old style stuffing box and hand tighten it with this packing and you will not have any problems--no heat, no scoring and no drips. The boatyards love the PSS dripless as they provide substantial income to install and repeatedly fix. They do not use dripless seals in nuclear submarines nor do they use flax that drips. Think about it....We have waited several decades for this new solution and it is finally here. I have used it in my own boat for the last 3 years. Perfect.

Well that's a whole lot of negative!
As true as your experience likely is, it would be a whole lot easier to understand if you gave a bunch of the different reasons why you have "spent more time in port fixing these units and the damage they caused".
From my experience (limited) with the PSS along with anything I've read from others, there are 2 issues that have been communicated. One being the backing off of the collar, easily fixed if you know that there is that potential and the other being the burning up of the seal due to trapped air (lack of water lub & cooling), which is not likely to happen if the operator burps it when their boat gets put into the water. The new ones all come with vents/water supplies and so that potential problem should now be gone??

If it is proven that it is a garbage product, I'll change mine, but I'd like to hear at least some of your countless problems first.

Thanks,
Extemp.

[delmarrey]

Originally Posted by Extemporaneous

Well that's a whole lot of negative!
As true as your experience likely is, it would be a whole lot easier to understand if you gave a bunch of the different reasons why you have "spent more time in port fixing these units and the damage they caused".

Ditto! And what damage could a PSS cause?
What is this black stuff you mentioned?
Also I have NEVER had a problem with my PSS's only the shaft they were attached to. Even with that they still put out less salt water then any grove maker (stuffing box) I've ever had.

[AnchorageGuy]

I have installed virtually hundreds of these and once installed never had someone come back for "service" since there is nothing to service. Ours is now over a year old and other than occasionally looking at it, it needs no attention. We repeatedly hear from users that have had the units in for ten years without any problems. So what exactly is this service that you did. We know a couple of dozen delivery Captains and we do deliveries ourselves. I know of no one that charges a surcharge because of the shaft seals and doubt anyone wanting to have their boat delivered would pay it. Chuck

[DeepFrz]

A tow boat captain wrote an article in Passagemaker a few years ago and talked about all the calls he got because of the dripless shaft seals. Gist of the article was, they are NOT maintenance free.

[Extemporaneous]

Originally Posted by DeepFrz

A tow boat captain wrote an article in Passagemaker a few years ago and talked about all the calls he got because of the dripless shaft seals. Gist of the article was, they are NOT maintenance free.

Went looking for the article, but no luck.
Do you recall what he was saying was involve in this maintenance?

Thanks,
Extemp.

[DeepFrz]

I suppose each manufacturer has their own recommendations. I really don't remember all that was written but making sure the bellows is pliable and not cracked, that the rotor hasn't slipped (as previously mentioned here) and that the manufacturer's replacement recommendations are followed. Also burping and making sure there is ample water flow. The newer ones have vent hoses that need to be taken well above the water line.

[AnchorageGuy]

That article is very, very old which is why it is so hard to find. It usually get an honorable mention any time the subject of these shaft seals come up. Chuck

[DeepFrz]

Originally Posted by Waterwayguy

That article is very, very old which is why it is so hard to find. It usually get an honorable mention any time the subject of these shaft seals come up. Chuck

Well, that comment got me off my chair and checking back issues. Didn't have to go to far. Article is from June 2007, page 118 of Passagemaker magazine. Chuck, that's not old. Granted some of the shaft seals that failed were probably old, but that's just the point.

Quote of first paragraph:

As an operator of a TowBoatU.S. rescue and towing boat I have responded over the last four or five years to a surprising number of assistance calls from boats that were sinking because a dripless shaft seal had failed and caused flooding.

I think that quote deserves honorable mention.

[DeepFrz]

I must also mention that the author does go on to say that a new and well maintained dripless shaft seal should provide good service and do what the manufacturer suggests it will do. But maintenance is a key theme in his article and that includes replacing the seals when the manufacturer suggests. (I feel another argument coming on that last sentence)...

[delmarrey]

Originally Posted by DeepFrz

I must also mention that the author does go on to say that a new and well maintained dripless shaft seal should provide good service and do what the manufacturer suggests it will do. But maintenance is a key theme in his article and that includes replacing the seals when the manufacturer suggests. (I feel another argument coming on that last sentence)...

And the same can happen with a stuff'n box, the hose can crack, the clamps come loose and the packing (seal) wear out. At least a PPS will not wear a grove in the shaft. AND, if the shaft were ever to come loose from the tranny coupler the PSS would keep it from falling away.

[Cran]

I have 1976 Albin Ballad with a shaft seal composed of a brass ring with two rubber seals-outboard and inboard, you have to pull the boat in order to replace the seals. Your photos do not match my rig but are really close.
When I replaced the seals on mine I went to the local bearing shop in town and they had the 25/34 mm seals. But you have to have the boat out of the water to replace.

[nhschneider]

Another bit of anecdotal drivel: I used to have a conventional shaft packing gland and it seemed like it was a continuous source of maintenance. Either it was dripping too much or not enough. Or I was worried that it was dripping too much or not enough. Two years ago when I replaced the engine, prop and shaft, I installed the Lasdrop Gen II seal and it's been perfect. It hasn't leaked a drop and runs cool. Installation was very easy. It's required no maintenance since I installed it.

Fair winds and calm seas.