stern gland greasing regime

[dylanwinter]

I thought that stern glands need grease squeezing in every few hours of running and then once you have stopped you turn in the grease until the greaser gets almost too stiff to turn.

I remember that the slug used to need 13 or 14 turns and it ate grease like it was going out of style

Harmony got half a turn every few hours of running and then a turn after the engine had stopped.

Clive, from whom I have just bought Centaur 2, said that his engineer had told him to add the grease while the engine /prop is still running and then knock it out of gear.

yours

Confused of Falmouth

 

[NormanS]

If you have a conventional stuffing box (gland) with conventional packing, it shouldn't need any grease at all. However, I give mine a turn about once a month, at the end of a trip, after the engine is stopped. (To prevent my tie getting caught up in the works, don't yknow).

If the gland leaks more than a few drips / minute while running, the gland needs to be tightened up.

 

[westhinder]

H

If you have a conventional stuffing box (gland) with conventional packing, it shouldn't need any grease at all. However, I give mine a turn about once a month, at the end of a trip, after the engine is stopped. (To prevent my tie getting caught up in the works, don't yknow).

If the gland leaks more than a few drips / minute while running, the gland needs to be tightened up.

I'd agree with that. The grease is not there to lubricate the gland when the prop is turning, the water takes care of that.. The grease prevents ingress of water when the prop is stationary.
If you have to keep pushing in more grease, you either have to tighten the compression nut(s) or replace the packing.

 

[dylanwinter]

H
I'd agree with that. The grease is not there to lubricate the gland when the prop is turning, the water takes care of that.. The grease prevents ingress of water when the prop is stationary.
If you have to keep pushing in more grease, you either have to tighten the compression nut(s) or replace the packing.

so there is no need to grease it at all during a long motoring session

blimey was I ever wrong

 

[Tranona]

Grease is a hangover from the days when stern tubes had a white metal bearing in the end, which did need grease. However most tubes do not have that (almost certainly including yours) so the grease just stops the possible minor leak of water when stopped. If you keep pumping grease in it blocks the tube and as it is a poor conductor of heat reduces the cooling effect of the water. Although i am not a fan of old fashioned things like this, properly adjusted - tighten until it runs just off cold - and it will not leak. If it does then perhaps needs repacking.

I know you get bees in your bonnet about certain things, but a stuffing box is nothing to worry about if it is properly packed and adjusted.

 

[dylanwinter]

Grease is a hangover from the days when stern tubes had a white metal bearing in the end, which did need grease. However most tubes do not have that (almost certainly including yours) so the grease just stops the possible minor leak of water when stopped. If you keep pumping grease in it blocks the tube and as it is a poor conductor of heat reduces the cooling effect of the water. Although i am not a fan of old fashioned things like this, properly adjusted - tighten until it runs just off cold - and it will not leak. If it does then perhaps needs repacking.

I know you get bees in your bonnet about certain things, but a stuffing box is nothing to worry about if it is properly packed and adjusted.

having lived with a 45 year old stern gland for five years on the slug which required strips of leather to be carefully wrapped around rotating shafts I am allowed to worry a little am I not?

 

[ghostlymoron]

having lived with a 45 year old stern gland for five years on the slug which required strips of leather to be carefully wrapped around rotating shafts I am allowed to worry a little am I not?

I think you'll find that your strips of leather were, in fact, old, grease impregnated packing. On Cobblers I replaced the packing last year with graphite impregnated cotton. It rarely need greasing as the graphite is an effective lubricant. You want to keep the stern tube clear of grease so that the water can get in via the cutlass bearing to cool the stern gland.

 

[Rhyddid]

http://coxengineering.sharepoint.com/pages/sternglands.

This good stuff , pun intended
:encouragement:

 

[dylanwinter]

I think you'll find that your strips of leather were, in fact, old, grease impregnated packing. On Cobblers I replaced the packing last year with graphite impregnated cotton. It rarely need greasing as the graphite is an effective lubricant. You want to keep the stern tube clear of grease so that the water can get in via the cutlass bearing to cool the stern gland.

so when do I tighten the greaser then?

hardly ever seems to be the answer

of course with the slug (until the cutlass was replaced with some special plastic - it needed greasing regularly otherwise the boat would sink

D

 

[ghostlymoron]

so when do I tighten the greaser then?

hardly ever seems to be the answer

of course with the slug (until the cutlass was replaced with some special plastic - it needed greasing regularly otherwise the boat would sink

D

See vyv cox's website for advice on greasing. It usually doesn't need doing whilst underway, half a turn after using the engine may stop any residual drips but isn't usually necessary, if the gland is tightened properly (so it runs warm but not hot).
The repair done to the Slug's rear end was incorrect IMO. The solid nylon bush effectively stopped water lubrication of the stern gland. The gland needed re-packing with modern graphite packing (fiver from ASAP) and adjusting properly which would have stopped any leakage economically rather than pumping masses of grease into it.
How are you going to get lily m to Scotland? You may have to KTR from Falmouth.

 

[dylanwinter]

See vyv cox's website for advice on greasing. It usually doesn't need doing whilst underway, half a turn after using the engine may stop any residual drips but isn't usually necessary, if the gland is tightened properly (so it runs warm but not hot).
The repair done to the Slug's rear end was incorrect IMO. The solid nylon bush effectively stopped water lubrication of the stern gland. The gland needed re-packing with modern graphite packing (fiver from ASAP) and adjusting properly which would have stopped any leakage economically rather than pumping masses of grease into it.
How are you going to get lily m to Scotland? You may have to KTR from Falmouth.

straight up the Irish sea

three blokes - two hours on - four off

just stick at it

not stop until I get to Skye - nor unless the weather goes crap big time

aiming for early may

we had a bit of a hoot on the journey up the North Sea

https://www.youtube.com/watch?v=djp-D5s-sik

 

[Tranona]

having lived with a 45 year old stern gland for five years on the slug which required strips of leather to be carefully wrapped around rotating shafts I am allowed to worry a little am I not?

Only if it is knackered. So the lesson is - make sure you don't buy something that is knackered, as it gives a false impression.

 

[dylanwinter]

Only if it is knackered. So the lesson is - make sure you don't buy something that is knackered, as it gives a false impression.

knackered is cheap

D

 

[Tranona]

knackered is cheap

D

Pleased to see that you seem to have not followed this maxim with your latest purchase!

 

[vyv_cox]

knackered is cheap

D

But graphite impregnated cotton packing is hardly expensive. Enough for many years for less than £10.

 

[KellysEye]

I used to grease the flax in the stuffing box every four engine hours, I pumped grease until the handle became stiff. The only way to find out how often to grease is try that, I would never dare to not grease it that's why the greaser is there.

 

[ghostlymoron]

Grease was needed when the packing was purely hemp/cotton/flax. Now that graphite impregnated packing is widely available and cheap you probably don't need grease anymore and are less likely to clog your stern tube and cause the gland to overheat.