New Drip-less shaft seal fail, and fix

[healhustler]

I've had my boat on the hard for the last 5 days in Stuart, FL. One of the items on the agenda was to install a new drip-less shaft seal. Initially, I wanted to replace the seal with the same PSS unit that I had since I bought the boat, which was no longer drip-less. I was encouraged by the Yard Super to go with a new big-buck Tides Marine Lip-Seal type since they were touting such great success with the recent installations. After installation of a new cutlass, a good shaft cleaning and prop & rudder reconditioning, we installed the new seal. In all fairness, I should say that in the area of the seal, there was about 1/2000's wear, and even though the seal felt OK going on the shaft, it wouldn't bite. It leaked from the very first turn. After several tries at adjustment, we gave up on it. Inspection of the seal after removal showed no damage, no wear, no anything.

We ordered the PSS seal for the 35 mm shaft immediately, and had it on the next day. Didn't leak a bit from the first revolution.

I'm reporting this just in case you're considering the Tides Marine seal. It is, no doubt, a very good product and worth the money, but apparently unforgiving when challenged with miniscule wear in smaller shafts like my own. Perhaps in larger shafts, this would not be the case. The yard had installed dozens of these seals with no issues, but in smaller shafts, a bit of wear may become critical.

 

[Nomad Willy]

husler wrote;

"It is, no doubt, a very good product and worth the money, but apparently unforgiving when challenged with miniscule wear in smaller shafts like my own. Perhaps in larger shafts,"

I disagree about the "good product and worth the money" part as the seal shouldn't be dependent on a perfect shaft surface as it's hard to not put very small dings or imperfections on shaft while handling it. I had an oil filled w lip seals system years ago called "NorScot" or something like that. It was troublesome also but I ran it for about a year. I've got an 8 year old PSS and it should probably be replaced fairly soon re the possibility of the bellows failing. Next time I have the shaft out I thinking I'll replace the PSS w a good old stuffing box.

PS My PSS shaft seal is still very dripless. But I've had trouble w the sleeve sliding fwd causing lots of water ingression to the extent it could have sunk the boat in a few hours. That problem is totally solved but then there's the bellows.

 

[healhustler]

PS My PSS shaft seal is still very dripless. But I've had trouble w the sleeve sliding fwd causing lots of water ingression to the extent it could have sunk the boat in a few hours. That problem is totally solved but then there's the bellows.

Yeah, I totally agree with the water ingression....it was worrisome. Whenever I adjusted the sleeve toward the bellows, I saw how much water came through when compressing the bellows away from the seal. The bellows on my old seal was pretty ugly, and the SS clamps on the bellows didn't seem to be of high quality....really rusty. The tendency of these types of seals is to mist a bit, however slight. Part of the upgrading is installing a couple of cameras in the engine room to observe things like this, but at least for now, I'm drip-less.

 

[Steve]

I changed a Tides seal on my Camano years ago. At installation the new seal leaked, a slow drip, as soon as I lowered it back into the water. I called a tech, John, at Tides who recomended I pull it fwd on the shaft a bit, move it from side to side then put it back in place. It never leaked again during the next 2 years I had that boat. I don't know what the problem was maybe the lip was "turned under" in a spot.
I Have a tides seal in my Monk it never dripped, but, I just changed it since I had owned the boat for 4 years, and I didn't know if it had ever been changed since built in 2003. The new one hasn't leaked since installation (only about an hour use since then) I wonder if your yard contacted Tides and what they had to say?
The Camano shaft was 1.5" or 38 mm
the Monk shaft is 1.75" or 44.45 mm
Steve W

 

[Nomad Willy]

Is the Tides Seal oil filled?

 

[sunchaser]

The tendency of these types of seals is to mist a bit, however slight.

My PSS don't leak or mist one bit.

 

[Steve]

The Tides seal is not oil filled, on my Monk cooling water from the raw water pump goes into the seal assy. via the tube shown in the second picture, it exits through the seal assembly by flowing through the cutless bearing and out. I don't remember the circuit on the Camano but it must have been similar. In that picture you can see a black ring on the shaft a couple of inches Fwd of the seal, that is a spare seal carrier with the spare inside it on the shaft. Otherwise the shaft must be baccked out at the coupling for installation of a new seal. As shown the old seal is pried out, cut off the shaft, the spare slipped back in place and capped. Some folks do this on the water I haven't and would be very nervous if I were to.

Steve W

 

[Delfin]

husler wrote;

"It is, no doubt, a very good product and worth the money, but apparently unforgiving when challenged with miniscule wear in smaller shafts like my own. Perhaps in larger shafts,"

I disagree about the "good product and worth the money" part as the seal shouldn't be dependent on a perfect shaft surface as it's hard to not put very small dings or imperfections on shaft while handling it. I had an oil filled w lip seals system years ago called "NorScot" or something like that. It was troublesome also but I ran it for about a year. I've got an 8 year old PSS and it should probably be replaced fairly soon re the possibility of the bellows failing. Next time I have the shaft out I thinking I'll replace the PSS w a good old stuffing box.

PS My PSS shaft seal is still very dripless. But I've had trouble w the sleeve sliding fwd causing lots of water ingression to the extent it could have sunk the boat in a few hours. That problem is totally solved but then there's the bellows.

It's not a bad idea to put a couple of ss clamps on the shaft just behind the carbon bearing surface to prevent that sliding. Also, when the set screws are loosened up for any reason, PSS wants them replaced, not reused.

There was a Tides on the shaft when I bought Delfin. Worked fine taking her to Ensenada, but after sitting on the hard for three years, she didn't leak when splashed, she gushed. PSS was used to replace the Tides and it has never leaked.

 

[Nomad Willy]

OK Steve I see it's more like the PSS or R&D seal. That seal (PSS) has a weak link when not installed by a professional .. Or one that reads and follows directions. The sleeve needs to be compressed a certain amount. One adjusts the position of the SS sleeve to or such that it is compressed a specified amount probably different for each size of seal re different propeller shaft sizes. Too tight and excessive heat or wear or both will come to pass. Also excessive pressure could be delivered to the mating surface of the SS sleeve and the carbon fibre seat in reverse. Too loose and leakage from vibration or thrust movement will take place. Thrust movement will be very different on different boats due mostly to how the engine mounts handle thrust. Very soft mounts like Yanmars allow much more shaft movement (and of course engine movement) than other more traditional mounts. A PSS seal could open up and allow water to freely flow in w these super soft mounts. Mounts designed to work w Aqua Drive and other similar drive systems will also be very soft and require more compression on the PSS bellows. It's conceivable that ther'e are engine mounts so soft that the use of a PSS seal is not practical or advisable.

It's not my nature to but w the PSS seal I did read the directions carefully and adjust the sleeve/bellows correctly and have had flawless performance.

Carl,
I put a shaft zinc (clamp) on first and then two hose clamps. I don't like to suddenly discover my boat is seriously leaking.

 

[Steve]

The Tides seal works like the seal on a hydraulic motor, that is, a lip seal on a spinning shaft. A hyd. motor shaft is a very hard and polished metal which I am sure helps even though a hyd system runs in the thousands of PSI. you can see the details here https://www.tidesmarine.com/
Steve W

 

[Northern Spy]

Shaft seals are the debil's work.

 

[Nomad Willy]

That's a little judgmental Spy.

 

[Northern Spy]

That's a little judgmental Spy.

Having spent the last 27 years installing, troubleshooting, and repairing the blasted things, I reserve that judgement. Never has anyone called me in the middle of the night or wrecked my weekend for repacking a pump, agitator, refiner, or other rotating shaft sealed with a simple packing, lantern rings, and a gland.

Mechanical seals are great if you are dealing with high linear shaft speeds, dangerous fluids, high pressure, zero emission requirements, volatiles, gasses, or erosive slurries (well, nothings great there).

We are talking about sealing a small diameter, slow speed, low pressure, clean water, low annual hours application.

Furthermore, seals are more digital in nature. The functional failures are hard to detect, and the failure effects can be hazardous to your boat. I can detect and correct (while in operation) an increase in drip rate of my packing. I can correct most deficiencies in the water. I can emergency repair it with my sock (unless it is summertime, I'll have to use a dishrag or something).

 

[Nomad Willy]

I"LL STAND DOWN 110% ON MY REMARK.


AND I'll agree totally w you. Even to the point of saying (I think I have) that the next time my shaft comes out (and it may be before Willy goes back in the water) I'll change back to a good old fashioned shaft seal. Who cares if the thing drips a bit? The chances of sinking your boat is almost non-existant. The security is way up there and the drips are about the smallest fly stuff ever heard of. Yes Yes and Yes.

 

[Codger2]

I can detect and correct (while in operation) an increase in drip rate of my packing. I can correct most deficiencies in the water. I can emergency repair it with my sock (unless it is summertime, I'll have to use a dishrag or something).

I have a PSS shaft seal in my boat that is 8 years old and has been no trouble. However, If I was a serious cruiser, which I'm not, I would replace it with a stuffing box. Like Spy says, you can adjust it, change the packing, notice an increase in drip rate, kick it and fix it if you have to, in the water with your cocktail napkin! (If that's all you have.) And you don't have to "Burp" it after the boat's been on the hard for awhile.

 

[Northern Spy]

Oh, I'm just grumpy because I spent a few hours of my day today analyzing mechanical seal failures. Double seal, with a modified API 53b buffer fluid arrangement. Suction pressure is excursioning over stuffing box pressure and contaminating the buffer fluid, wearing the seal faces, if your interested. Pump costs more than all of our boats, and the seal costs more than many of our boats...

 

[Art]

Although I've used dripless before - I have standard seals now all the time. Safer and easier to work with for sure!

For S&G....

PSS Install Video - YouTube

 

[Marin]

Shaft seals are the debil's work.

Don't know about debil's work, but our boat has conventional packing glands albeit with a raw water feed from each engine to its associated log because of the doubled-up cutless bearings in the shaft tunnels. Our packing glands are packed with low-tech flax (the recommended material by the yard we use) and they don't drip at rest, drip maybe once every 10 or 15 minutes when turning at cruise rpm if I sit there and watch them long enough, and both logs run dead cold.

They have been repacked once in the 14 years we've had the boat and that was not because they needed to be but because we had the shafts out of the boat so it made sense to do it.

As Spy says, easy to adjust when necessary and no worries about sudden failures. KISS.

 

[Art]

PACKING STUFFING BOX

http://www.pbase.com/mainecruising/stuffing_box&page=1

Also: Many Other Good Items - As instructive as the Stuffing box link:

http://www.pbase.com/mainecruising/boat_projects

 

[FF]

If the shaft stuffing box his there , DURAMAX .

No failures , no drips , no overheating.

And simple enough most owners and yards can do it right the first time.

A "spare packing" should it be needed in a few decades tales little storage space .

Go Modern!

 

[Dougcole]

The problem with stuffing boxes most of the time is access. They can be a bear to adjust when they are hard to get to. Though I guess dripless would be hard to change in that scenario as well.

 

[Nomad Willy]

Art thank you so much for the seacock link. I need to do that but I think I've got a different brand.