Dripless shaft seals. PSS v Tides

[Tranquility BC]

We’re new to trawlers having just bought a KK which has a PSS dripless shaft seal. Rather alarmingly it started to spew water at rest but two knowledgeable skippers identified the problem as the ss puck had slipped due to loose set screws. Emergency over - problem fixed for now.

We’re new need to haul to either service the PSS shaft seal or replace it with a Tides. I would be very interested to hear from owners whether they prefer the PSS or the Tides. I hear good and not so good about both.

 

[Mac2]

That’s a common problem with the PSS. Put a hose clamp, or something else (they make a stainless clamp that resembles a shaft zinc) in front of the puck to prevent this from happening again. I have had both. They are both excellent products. My current boat has tides. I liked the idea of the spare lip seals on the shaft. I plan on cruising Alaska and was told the silty glacier water (similar to wet sanding) wears shaft seals down-have no idea how valid this is.

 

[Tranquility BC]

Thank you. I padded the shaft with rescue tape to protect it and put a hose clamp on top to stop the puck slipping. I also like the backup of a spare lip seal. I’ve heard that the shaft has to be 100% perfect for the Tides to seal correctly and that it does weep a bit of water. In your experience is this correct?

 

[MVCalypso]

At the risk of being called a nautical Luddite, I'll suggest that you might consider tossing the "drip-less" seals back into Mr. Jone's locker. An experience years ago involving an urgent haul out to remove an essentially new (a week or so old) fancy shaft seal that tried to sink my Valiant (pre-trawler days) made me a staunch supporter of good old fashioned stuffing boxes...
The key is to use the right packing material.
Don't use traditional flax, that just gives you a drip rate dependent on the shaft speed.
I'm also not a fan of graphite packing due to complications of graphite in contact with shaft materials immersed in salt water.
I prefer teflon packing.
It can be adjusted to not drip at rest, and not drip when running either. Has worked perfectly for me for 25+ years. once set up I've also never needed to re-adjust the teflon packing to comepsate for packing wear to compaction.
The only hassle has been the need at my last haul out to convince a yard worker to adjust the stuffing boxes to NOT leak. An IR temp gun is helpful in proving to them that the shaft was not overheating. They had trouble accepting that a flow of dripping water was not needed for lubrication with teflon packing.

 

[NoRain]

Thank you. I padded the shaft with rescue tape to protect it and put a hose clamp on top to stop the puck slipping. I also like the backup of a spare lip seal. I’ve heard that the shaft has to be 100% perfect for the Tides to seal correctly and that it does weep a bit of water. In your experience is this correct?

When you relocated the rotor to the correct position, did you use 2 *brand new* set screws? Technically only the one touching the shaft needs to be new, but it is quite critical it is new, not re-used.

 

[Tranquility BC]

Yes. I did and a bit of blue Loctite

 

[Tranquility BC]

At the risk of being called a nautical Luddite, I'll suggest that you might consider tossing the "drip-less" seals back into Mr. Jone's locker. An experience years ago involving an urgent haul out to remove an essentially new (a week or so old) fancy shaft seal that tried to sink my Valiant (pre-trawler days) made me a staunch supporter of good old fashioned stuffing boxes...
The key is to use the right packing material.
Don't use traditional flax, that just gives you a drip rate dependent on the shaft speed.
I'm also not a fan of graphite packing due to complications of graphite in contact with shaft materials immersed in salt water.
I prefer teflon packing.
It can be adjusted to not drip at rest, and not drip when running either. Has worked perfectly for me for 25+ years. once set up I've also never needed to re-adjust the teflon packing to comepsate for packing wear to compaction.
The only hassle has been the need at my last haul out to convince a yard worker to adjust the stuffing boxes to NOT leak. An IR temp gun is helpful in proving to them that the shaft was not overheating. They had trouble accepting that a flow of dripping water was not needed for lubrication with teflon packing.

Thank you. There are advantages to using traditional methods with a modern twist.

 

[Mac2]

Thank you. I padded the shaft with rescue tape to protect it and put a hose clamp on top to stop the puck slipping. I also like the backup of a spare lip seal. I’ve heard that the shaft has to be 100% perfect for the Tides to seal correctly and that it does weep a bit of water. In your experience is this correct?

I was told the same thing. The tech said they were not dripless, but they drip less. I got the impression he had to say this to cover his ass. My boat is steel, so I didn’t want any drips. It’s been about 5 years with no drips on either Tides.

 

[sean9c]

Use this

Stubby Pro Shaft Seals - R.E. Thomas Marine Hardware

Order a Stubby Pro Shaft Seal from R.E. Thomas Marine Hardware today! Stubby Pro Shaft Seals are the safest and most dependable shaft seals available.

retmarine.com

 

[Frosty]

Use this

Can you tell a little bit about your experience with it? I'm always interested in products I'm not familiar with. Since you know the product I would love to hear more than "use this" if you care to share.

 

[O C Diver]

I had a PSS on my boat. 6,000 hours without an adjustment. Bought a rebuild kit with bellows, orings, set screws, and hose clamps. Good for another 6,000.

IMO, it's foolish not to hook up the raw water feed off the engine (some don't). IMO, you're flushing the seal and cutlass bearing, and keep heat from building up.

Ted

 

[Mac2]

Use this

Stubby Pro Shaft Seals - R.E. Thomas Marine Hardware

Order a Stubby Pro Shaft Seal from R.E. Thomas Marine Hardware today! Stubby Pro Shaft Seals are the safest and most dependable shaft seals available.

retmarine.com

That looks very good! I watched the video. Looks like regular packing rings, but didn’t show if there was a mechanism to tighten the packing rings, or how often you have to make adjustments, or inspect.

 

[Mac2]

IMO, it's foolish not to hook up the raw water feed off the engine (some don't). IMO, you're flushing the seal and cutlass bearing, and keep heat from building up.

Learned this the hard way. Installed two new PSS shaft seals. Directions indicated if my shaft was “x” long and I didn’t go faster than “y” (I think it was around 12 knots but not positive) I could use a vent tube instead of a water feed. Knowing that impellers fail, I thought it would be smarter to use the vent configuration-Wrong!! Smoked both shaft seals on the first trial run. Hindsight, I believe it was because I had cutlass bearings on both ends of the shaft. Im guessing directions didn’t take into account a short shaft having a bearing on each end, which obviously restricted water flow to the dripless seal.

 

[Portage_Bay]

I have found PSS to be reliable. Have had them on two boats. I have no experience with tides.

 

[luna]

If your existing shafts are in good shape or can be made to be in good shape, I would consider installing these: Norscot Dripless Propeller Shaft Seal

The lip seals held in the housing run in what they are designed to run in, oil.
No raw water piping or flow required.

 

[Jay N]

Well . . . After 28 years of having PSS in WESTERLY, I am returning to a convention packing gland. Over those 28 years, there has been 5 PSS shaft seals installed, the last two were the silicone bellows PRO models. After about year 4, the carbon seat becomes mis-aligned with the SS rotor and starts chattering and sending carbon particles out in addition to a fine mist (contained by a plastic shield). According to an engineer friend who has worked with PSS, this is probably due to a slight shaft mis-alignment. Apparently, there are boats built where the shaft is not exactly centered in the shaft log, and there is eventual contact wear that increases with usage (550 hours/year).

As an experiment, last year I disconnected the raw water feed from the engine (as I suspected the water pressure may not have provided positive pressure at the seal), and vented the seal, finding no increase in seal temperature or change in seal contact.

The new packing gland will be fitted with 3 rings of Teflon packing (ABYC disapproves of graphite), and I am anticipating the kind of service and service life experienced by M/V CALYPSO in post #4 above.

 

[Tranquility BC]

Thank you- certainly food for thought.

 

[CharlieO.]

That looks very good! I watched the video. Looks like regular packing rings, but didn’t show if there was a mechanism to tighten the packing rings, or how often you have to make adjustments, or inspect.

That is the unit I installed, it is great. The three studs are where you can tighten your packing. I installed the teflon packing and as Dave B. (MV Calypso) says it can be adjusted to not leak. Mine does not drip at the dock or underway, and I do verify it is not getting warm with an IR gun. I have about 200 hours on it and have not made any adjustments to it yet.
I also installed a fiberglass shaft log that was made for me by the same company. I would not hesitate to use their products again and recommend them.

 

[jleonard]

I installed Tides seals in 2 boats. First one was totally dry after 6 seasons.
2nd one was totally dry after 15 seasons.
In both cases I installed a spare seal on the shaft “ just in case”.
Never needed it.

 

[BDofMSP]

If you choose PSS (like I did) make sure you choose the Pro series. Dramatically better for only a little more money. Wrote about the experience here

PSS Seal Maintenance

Dripless shaft seals are extremely low maintenance, so for many people they aren't top of mind when they're doing their engine room inspections. Posting this to increase awareness for those who are less experienced. After my recent incident where the fuel filter canister developed a crack and...

www.trawlerforum.com

 

[Tranquility BC]

Thank you all for sharing your hard won experience. In the end it’s a matter of ‘you pay your money and make your choice’.

 

[rgano]

I have owned traditional, a unique grease-packed set from Grand Banks, PYI, Lasdrop, and finally Tides.

The best design and most robust was PYI with their face seals which replaced two 14-year-old Lasdrop face seal style - the PYIs were just bigger and better, and I put them in because the shafts were coming out anyway. Installed twins in 2008 and running fine after thousands of miles when boat sold in 2015.

My current Tides lid seal type gives me less confidence because of the possibility of shaft issues causing it to leak, BUT after ten years on the original seal, the darned think won't leak. Spare seal already on the shaft is a neat idea. This could well be the original seal from 2005 new boat year because of the low hours the boat had when I bought it in 2015. Boat lives in a lift which is why I don't worry about it leaking while stationary, which it does not do.

I have no complaints about a Teflon packed conventional packing, but I am not about to change from even a Tides seal to the old fashioned style. They can be more maintenance than you might think.

 

[Hornloaded]

I bought a power boat in 2020. Twin Cummings engines with Tides seals. One day going out to the islands, a fuel filter clogged and I lost an engine. Turned back to shore (about 23 miles) and began going home on one engine. Halfway across the channel I lost my other engine (clogged fuel filter). Luckily, I got the engine restarted but decided to go into the engine room to see what my filter gauges were saying. I discovered 2-3' of water in the engine room. The Tides seal on the starboard engine had twisted the bellows hose completely in half. I had to call out a Pan-Pan to the Coast Guard. They were able to come out and de-water the boat and tow me in for an emergency haul out. After talking to lots of experienced people, they all recommended to change to PSS-Pro and put individual thru-hull water feeds to each seal.
Once we pulled the shafts and got the old Tides seal out, I was expecting to see a melted seal housing glued to the shaft. We found nothing wrong with the failed housing! The Tides were fed water from each engine with a cross over tube feeding each seal in case of an engine failure. I know the seal was getting water because when it all happened and I was in the engine room accessing the problem, I saw that crossover tube spewing lots of water out since my port engine was still running.
I'm VERY happy with my new setup. PSS-Pro and dedicated thru-hull water feed to each shaft.

 

[Capt Dan]

We’re new to trawlers having just bought a KK which has a PSS dripless shaft seal. Rather alarmingly it started to spew water at rest but two knowledgeable skippers identified the problem as the ss puck had slipped due to loose set screws. Emergency over - problem fixed for now.

We’re new need to haul to either service the PSS shaft seal or replace it with a Tides. I would be very interested to hear from owners whether they prefer the PSS or the Tides. I hear good and not so good about both.

Check out "stubby pro shaft seals madr bye R E Thomas in Maine. They make beautiful stuff

 

[Mac2]

The Tides seal on the starboard engine had twisted the bellows hose completely in half.

I don’t understand how this happened. The crossover is providing cooling water, so nothing should have changed to the seal. Im guessing you didn’t have spare fuel filters-the reason you turned back?

 

[Hornloaded]

I don’t understand how this happened. The crossover is providing cooling water, so nothing should have changed to the seal. Im guessing you didn’t have spare fuel filters-the reason you turned back?

At the time I had no easy way to fix the filter problem, heading back was the logical solution. I have since installed a bypass system that I can engage easily. Everyone that looked at the Tides was stumped. No logical explanation, the force required to rip the hose apart is huge so it defiantly grabbed the shaft tight.

 

[rslifkin]

t the time I had no easy way to fix the filter problem, heading back was the logical solution. I have since installed a bypass system that I can engage easily.

A bypass is not a solution to a clogged fuel filter, it's just a good way to clog the on-engine filter or cause damage. The solution is to either have a second filter plumbed in that you can switch to, or to stop and change the filter, then bleed the system.

 

[Hornloaded]

My bypass is a fully filtered feed coming off my fuel polishing system (10 micron). Takes seconds to engage. Changing a filter in 5' seas would be a real challenge.