Stern Gland for an aluminium boat

[Gubbo]

I need to replace the stern gland on my aluminium Sarum 28 that I am re-fitting
It's a conventional layout with at 1 1/8" stainless shaft running through an aluminium stern tube with a 2" outside diameter.
There is a cutless bearing at the inboard end as well as the outboard so the shaft is well supported.
I have removed the existing Halyard seal (of indeterminate age) because it was leaking oil when turned so I'm assuming its past it's best and I understand spares are no longer available. This is a big refit project for me and so I want to get such an important component right before I install the new engine.

I don't really want to introduce more bronze to the aluminium so am looking for alternatives.

I have seen a photo of a composite traditional stuffing box on Vyv Cox's website and believe this may be just the job...but I can't find them for sale.

The volvo type would be great, I've had one before, but they are not available in the size I need.

So now I'm considering the PSS seal, particularly as it doesn't rely on perfect prop shaft surface as may be the case for lip seal types.

Your opinions please...

Richard.

 

[Tranona]

Is it the diameter of the stern tube that is the problem for the Volvo? If it is too small you can have a sleeve made to bring it up to the required diameter. Obviously if it is too large nothing you can do. Otherwise look at Tides marine. Also lip seals but in a non metallic housing and attached to the stern tube with a bellows which is available in different sizes. Very good bit of kit.

 

[vyv_cox]

I believe that the seals in a Halyard Marine gland are bog standard lip seals that can be bought at an automotive supplier or any number of online traders. If there is no identifying number on the old seals the dimensions OD and bore should be sufficient.

However, I have a PSS myself, perhaps eight years old now, and it seems totally reliable. I did have one problem with it when the stainless rotating face became pitted, probably because I did not flush it with fresh water when we hauled out. I reversed the seal and have had no further recurrence. I heard from one other user with the same problem but otherwise no adverse feedback. They are fitted as standard by a very large number of makers, which must say something.

I know that TNorris sell traditional stern glands, probably Lake Marine do and I would look at ASAP.

 

[Gubbo]

Yes I had a look at a tides marine "one-series" yesterday. I liked the all plastic construction but thought the single o-ring a bit lightweight. Is this the type you suggest or their more expensive "sure-seal" version.

The volvo seal problem is that they don't do one for imperial 1 1/8" shaft.

May have rejected the PSS after some overnight thinking. Their own literature suggests it sprays graphite dust around for the first few hours. Unfortunately graphite is an enemy of aluminium so best avoid coating the engine bay with it!!!

 

[vyv_cox]

The graphite spraying is very minor indeed. I suspect they put the phrase in to guard against claims from a certain type of person. Many aluminium boats are fitted with them.

 

[Gubbo]

The graphite spraying is very minor indeed. I suspect they put the phrase in to guard against claims from a certain type of person. Many aluminium boats are fitted with them.

Ah that's helpful because the PSS seems to fit the bill in every other way. Is the graphite issue mainly during the initial runs (during which I could rig a shield)?

 

[rogerthebodger]

I have a PSS seal on my steel boat. I also noted the comment about "spraying of graphite " but when I put my boat in operation 5 years ago there was no "spraying of graphite" or even water at any time.

My boat is in service all year round.

 

[vyv_cox]

Ah that's helpful because the PSS seems to fit the bill in every other way. Is the graphite issue mainly during the initial runs (during which I could rig a shield)?

I don't remember any significant graphite at all. Once run in, which I guess takes only a few minutes, there is a micron-thick film of water between the faces, so there is no contact between the faces and the film is so thin that no water leaks out.

If you look at the PSS photos on my website at http://coxengineering.sharepoint.com/Pages/Sternglands.aspx you can see a very faint black line up the bilge in the first photo that might be graphite. I think this is the worst you can expect.

 

[Gubbo]

Many thanks for all the practical advice.
Now I know what to look for, and given that my engine bay is epoxy painted anyway, I think the advantages of the PSS outweigh the small amount of maintenance needed.
Now to find one in stock....

 

[vyv_cox]

Mine came from Aquafax.