How much water is normal near stuffing box?

[Kgatesma]

We get about a quarter inch of water here (H35.5). Too much?

I imagine as the boat heels the water rolls down the black holes to the bilge.

 

[Will Gilmore]

That doesn't seem like a lot of water, but the goal is no water.
Look for its sourced, you may easily be able to stop it. It could be condensation, but probably not.

- Will (Dragonfly)

 

[SG]

Kgatesma -- unless I'm mistaken, that's not a stuffing box. It's a shaft seal.

Assuming you don't have a bent shaft or a misaligned engine, etc. , it's usual for there to be a few "drops" of water to be emitted by the shaft seal as it starts to spin. On our J/Boat (19 years ago when we got her) we had a flexible, clear plastic shield installed because we noticed on other boats a line of corrosion on metal parts in a various other boats' engine rooms where the sea water had created a line orthogonal to the shaft. It was subtle, but consistent on a variety of manufacturer's boats. The seawater usually just evaporated, but anyway....

Your boat doesn't have a vibration isolation fitting between the engine and the shaft, so you have more vibration at start-up or from use.

Do you have a feathering or folding prop on your Hunter? If not, then you may have a shaft that turns constantly.

 

[Ralph Johnstone]

Kgatesma -- unless I'm mistaken, that's not a stuffing box. It's a shaft seal.

And the difference is ......................... ? ? ?

 

[SG]

Is there a difference ? ? ?

Yes. They function completely differently.

The expectations of performance are different. They are devices that function very differently.

If you over-tighten a stuffing box "lock nut", you'll have negative consequences. You should expect some very, slow, intermittent dripping while the shaft is turning.

With a Shaftseal, you should expect no real noticeable dripping unless something is amiss. (As I pointed out, the key is "noticeable" because their is often a momentary "spitz" which you'd not likely notice -- only the traces of it.) If you have a vibration issue where the parts (rotor and pressure block/plate) don't mate; or, you don't maintain reasonable pressure by adjusting the "compression" of the bellows, etc.), then you might get a bit of water.

PS.- I didn't see much adjustment room and no "protection" donut/or a stopper on KGatesma's installation.

 

[Ralph Johnstone]

If you over-tighten a stuffing box "lock nut", you'll have negative consequences.

And the over-tightening of the "lock nut" affects the packing how ................................................. ? ? ?

 

[SG]

The packing wears out from over heat or scores the shaft.

You need some water to lube the packing.

http://www.boatus.com/boattech/casey/stuffing-box.asp

 

[Meriachee]

If that is in fact a PSS, where's the vent hose?

 

[SG]

If that is in fact a PSS, where's the vent hose?

Not all PSS Shaft Seals have vent tubes. They only used to use those vent tubes for higher speed vessels or ones that were pulled frequently in and out of the water. My first boat with one (a Sabre 42 #4) didn't have a vent tube. Our current boat didn't originally in '98 from the factory, when we replaced the assmbly (out of an abundance of caution) about 5 years ago, the new model did.

 

[Ralph Johnstone]

The packing wears out from over heat or scores the shaft.

Yes, of course, when you over-tighten the stuffing box NUT, but not when you over-tighten the LOCK NUT. The only thing that causes is skinned knuckles when you try to undo the lock nut after a year of sitting there.

 

[SG]

Yes, of course, when you over-tighten the stuffing box NUT, but not when you over tighten the LOCK NUT. The only thing that causes is skinned knuckles when you try to undo the lock nut after a year of sitting there.

;^))). Yes. I wrote loosely. Not about the distinction between that nut and that not so loose screw.

 

[Meriachee]

Not all PSS Shaft Seals have vent tubes. They only used to use those vent tubes for higher speed vessels or ones that were pulled frequently in and out of the water.

That's not totally true. The vent tube is for expulsion of any air that can get into the tube through gravity, cavitation in reverse or whatever. Vent tubes were standard offerings from a few years ago when I bought mine, as I remember calling them and having that discussion at the time. Air against that seal will kill it in a hurry.

 

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[SG]

Not all PSS Shaft Seals have vent tubes. They only used to use those vent tubes for higher speed vessels or ones that were pulled frequently in and out of the water.

That's not totally true. The vent tube is for expulsion of any air that can get into the tube through gravity, cavitation in reverse or whatever. Vent tubes were standard offerings from a few years ago when I bought mine, as I remember calling them and having that discussion at the time. Air against that seal will kill it in a hurry.

I agree that PSS believes it is better to have vent tubes; and, for a number of years, the just made that change which they view as an improvement. Notwithstanding that, PSI didn't always have that standard. Those units functioned well in most sailboat application.

Our J160 with its 85 hp Yanmar has had to motor on long passages for extended period of over 18 hours continuously at 2800 rpm (at closer to 9 than 8 knots on numerous times. It wasn't an issue. When we replaced the Shaftseal, there was almost no real wear on the rotor plate and carbon block. The issue was that after over a decade, my mechanic said that ozone and other chemicals might make the bellows less flexible. The bellows kit alone vs the new seal with my discount seamed like not a big deal. The big dollars was on pulling the shaft and rest of the labor. There's a story that goes with that "let no good deed go unpunished", but I'm on an iPad and tired of pecking ;^))).

 

[Meriachee]

I think it's relatively important to keep current information just that, current. There's a lot of history and first person experience here, and we shouldn't be leaving potential buyers with legacy data to cloud their judgement. The stuff was sold that way at one time, your's is an example of that. Mine is an example as well, with a nylon barb, something that was replaced with steel after mine was made and who knows what revisions have come onto play along the line.

 

[SG]

I think it's relatively important to keep current information just that, current. There's a lot of history and first person experience here, and we shouldn't be leaving potential buyers with legacy data to cloud their judgement. The stuff was sold that way at one time, your's is an example of that. Mine is an example as well, with a nylon barb, something that was replaced with steel after mine was made and who knows what revisions have come onto play along the line.

So, Meriachee, would you replace your PSS Shaftseal if it were working very well and showed no wear for $400 (or whatever) just because it didn't have the newer vent tube?

I accept that PSS believes and has concluded that it prefers to err on the side of a more durable and (relatively) trouble free product by making the tube "standard".

I'm not so sure. The technology is pretty tried and true.

If I had a choice of buying an new "old" one out-of-box , I'd would not buy one at a discount over the newer ones with the vent tube; but, anyway....

P.S. -- The vent tube might be viewed as a vulnerability -- but that's just speculative. If you leaned into it and sheared it, you'd have a 3/8" hose filling the boat up. There have been some reports improper installations (hose too short or not attached with the open-end as directed. If properly installed with the open end high enough, they apparently don't release water in the normal course of human events.

 

[Meriachee]

So, Meriachee, would you replace your PSS Shaftseal if it were working very well and showed no wear for $400 (or whatever) just because it didn't have the newer vent tube?

That wasn't my point. In post #9, the comment was made that the tube only applied to power boats. That could be taken out of context by somebody with little to no knowledge of these things and influence a decision. We'd be far better off guiding these potential buyers based on current offerings and help them understand the rationale, and how to plumb the thing such that the risk of the possible vulnerability is mitigated. As well, for what little it's worth, alleviate questions people may have over different versions.

It would seem that the first post shows a very early version. I think we all agree that if it is a PSS, that there shouldn't be any water at all coming in.

 

[Terry Cox]

We get about a quarter inch of water here (H35.5). Too much?

To your question, after I hand tighten our stuffing box (our packing material is in fair condition, but due to be replaced; last replace in 2011) there should be no drips when the shaft is at rest, and maybe six to eight drips per minute when the shaft is spinning. Depending upon the age and/or amount of use, you may need to replace the packing material. Making the adjustment mentioned above should provide some indication.