shaft seals, lip seals,..oh my

[sailorboy1]

I need to replace my shaft seal this winter. It is an old PSS without vent tube. The big problem is it got a hole in the rubber bellows boot, but it leaks a little from the face also.

So there are shaft seals and lip seals what are the pros/cons of each? Seems the cons to the shaft seal is the bellows and the carbon ring. The con of the lip seems to be wear on the shaft from the seal and it would also seem to me the lip would wear.

Then there are the various shaft seal makes. We all know the PSS and my issue of course is that bellow that is suppose to be replaced every 6-8 years. Then there is Lasdrop that has a design with a rigid tube and the spring tension, and for which there doesn't appear to be as much "discussion about.

There there is the Volvo seal, which I gave up even looking for design info.

So just what is one to do? I don't mind spending an extra $100 to get a better seal as it seems nothing in the total project picture.

And then I've also thought of just going to packing!

OH MY, what is one to do?

[propellanttech]

Originally Posted by Don Lucas

I need to replace my shaft seal this winter. It is an old PSS without vent tube. The big problem is it got a hole in the rubber bellows boot, but it leaks a little from the face also.

So there are shaft seals and lip seals what are the pros/cons of each? Seems the cons to the shaft seal is the bellows and the carbon ring. The con of the lip seems to be wear on the shaft from the seal and it would also seem to me the lip would wear.

Then there are the various shaft seal makes. We all know the PSS and my issue of course is that bellow that is suppose to be replaced every 6-8 years. Then there is Lasdrop that has a design with a rigid tube and the spring tension, and for which there doesn't appear to be as much "discussion about.

There there is the Volvo seal, which I gave up even looking for design info.

So just what is one to do? I don't mind spending an extra $100 to get a better seal as it seems nothing in the total project picture.

And then I've also thought of just going to packing!

OH MY, what is one to do?

Oh my! indeed.

If you google dripless shaft seal, you will be amazed at all the different ones. They all work similar, but all have some differences.

I like dripless shaft seals, but the group tends to be divided. One problem with a dripless seal, it the ultimate effort to make sure the face and seal meet as perfect as possible (parallel). Also, if you have any bend in your shaft (shouldn't) a dripless will leak some.

I'm also a vented type. I just don't like the idea of a vacuum possibly being pulled on the bellow. Probably would only happen surfing in a sailboat, but still.

James L

[delmarrey]

All the new PSS's have the vent/water tube now. Reason being, if air is trapped inside it will over heat.

If the PSS is not installed squarely it may leak.

If the shaft vibrates or is bent the PSS may leak but so will any other type of shaft seal.

A lip seal has to be dead on center a face seal (PSS) does not.

As to what to do? That will be up to you!

[Hudson Force]

I just added the PSS with the vent tube last year. For the first 38 years my boat had the same well functioning stuffing box and now you are suggesting that I'll need a refit every 6 to 8 years? I rather spend twenty minutes to change the stuffing in the water than take on all the work to change the bellows on the hard. Maybe I've made a bad choice! The thick rubber hose holding my stuffing box remained without any degradation for the 27 years that I was maintaining things before the PSS.
PSS'd on & PSS'd off?

[sailorboy1]

Originally Posted by CaptForce

I just added the PSS with the vent tube last year. For the first 38 years my boat had the same well functioning stuffing box and now you are suggesting that I'll need a refit every 6 to 8 years? I rather spend twenty minutes to change the stuffing in the water than take on all the work to change the bellows on the hard. Maybe I've made a bad choice! The thick rubber hose holding my stuffing box remained without any degradation for the 27 years that I was maintaining things before the PSS.
PSS'd on & PSS'd off?

Sorry, guess you didn't read all the info. On the thread when mine started leaking a lot of people said replacing the bellows isn't needed and never leaks. But tell that to mine that is pissing water out the side till I wrapped it with resue tape. And I quote (and I didn't do the bold I just copied and pasted):

"As with any rubber hose below waterline, the PSS bellows must be inspected on a regular basis for any sign of wear, aging or chemical deterioration. PYI suggests preventative maintenance. The PSS bellow should be replaced in six year intervals. During bellows replacement it is recommended the o-rings & set screws in the stainless steel rotor also be replaced."

[propellanttech]

That is one reason I suggested the Google method.

There are dripless seals which are built to last much longer than the PSS.

I have to give cudos to PSS, but their competitors are starting to pass them with the newer designs.

Also, if using a graphite seal, it is basically impossible to overheat. The graphite will self lubricate. It will wear in this situation, but it could go like that for many, many years.

I will have a dripless seal, just not a PSS.

James L

[bobconnie]

Ive tryed them all!(almost) and will stick with a old fashion packing style ! Ive fixed them at sea at the dock ect ! never had any problems, and the small amount of leakage is no problem in most boats ! if ya leave for A LONG while and worry about your bilge pump just tighten the packing up till no leak and reajust when ya come back ! always works for me ! and much cheaper then the Trick stuff !! just my 2 cents

[propellanttech]

Originally Posted by bobconnie

Ive tryed them all!(almost) and will stick with a old fashion packing style ! Ive fixed them at sea at the dock ect ! never had any problems, and the small amount of leakage is no problem in most boats ! if ya leave for A LONG while and worry about your bilge pump just tighten the packing up till no leak and reajust when ya come back ! always works for me ! and much cheaper then the Trick stuff !! just my 2 cents

Some people do not like dripless seals. That is the way of things.

I say, use what you like.

James L

[cal40john]

Well there's how often you're told you're supposed to change bellows on dripless seals compared to how often people really do it, and the same is true for the hose on stuffing boxes.

From: How To: Stuffing Box Upkeep | Cruising World

A conventional stuffing box requires little maintenance: 
Periodically change the ropelike stuffing, inspect the hose clamps for rust, and replace the flexible hose every five years or so. "Hands-On Sailor" by Steve D'Antonio from our November 2011 issue.

[delmarrey]

Originally Posted by propellanttech

Some people do not like dripless seals. That is the way of things.

I say, use what you like.

James L

Ditto! Choose what you like and if it turns out not so good for you then change. Everything requires maintenance! It all comes down to how well things are installed and how well they are running.
A bent wheel will ruin the suspension on any car if let go long enough. It's just a matter of choice. Murphy will get ya no matter what you choose and that's the way things are. We still lost two space shuttles even with all the check lists and professional work.

Although, there is still junk out there and it takes experience or professionalism to know the difference. As shaft seals go, there are very few that need rejecting.

[sailorboy1]

not getting many opnions on seals other than PSS

anyone with experience with Lasdrops?

[delmarrey]

Originally Posted by Don Lucas

not getting many opnions on seals other than PSS

anyone with experience with Lasdrops?

If you google search the brand names from the pulldown tab above I'm sure there are some threads on them.


e.g. Lasdrops - Google Search

[Cheechako]

Originally Posted by bobconnie

Ive tryed them all!(almost) and will stick with a old fashion packing style ! Ive fixed them at sea at the dock ect ! never had any problems, and the small amount of leakage is no problem in most boats ! if ya leave for A LONG while and worry about your bilge pump just tighten the packing up till no leak and reajust when ya come back ! always works for me ! and much cheaper then the Trick stuff !! just my 2 cents

simple, cheap, not finicky, works well... KISS

[Matt Johnson]

Originally Posted by Don Lucas

not getting many opnions on seals other than PSS

anyone with experience with Lasdrops?

I installed a lasdrop a year ago.... Cannot get the thing to stop spraying water! I've aligned the engine, but that was square. I guess I could have a bent shaft, but I get no vibration. It was ok while I was in fresh water, now that I'm in salt, the spray and constant pumping is driving me crazy. Last night, the bulge pumped 4 times in 24 hours.

[Matt Johnson]

Originally Posted by funjohnson

I installed a lasdrop a year ago.... Cannot get the thing to stop spraying water! I've aligned the engine, but that was square. I guess I could have a bent shaft, but I get no vibration. It was ok while I was in fresh water, now that I'm in salt, the spray and constant pumping is driving me crazy. Last night, the bulge pumped 4 times in 24 hours.

Can't edit- I installed the one with rubber bellows not the hose.