# Stern gland grease?



## Classic30 (Aug 29, 2007)

A quick question: What do you guys use on the stern gland?

Can it be just any typical marine grease like the INOX MX-8 or does it have to be something special given that it's constantly under water?? 

Thanks,
Cameron


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## CalebD (Jan 11, 2008)

Cameron,
By 'stern gland' do you mean the gland the prop shaft goes through?
If so this link by MaineSail will help: Re-Packing A Traditional Stuffing Box Photo Gallery by Compass Marine at pbase.com

No grease, just packing. Water does the lubricating.


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## mitiempo (Sep 19, 2008)

Caleb
Some stern glands are designed for grease, either have a grease nipple or a remote greaser. It seems to be common to UK built boats as I have owned 2 that way and have seen it on others. But it was years ago and I am not sure which kind of grease - water pump grease maybe?


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## tdw (Oct 2, 2006)

Cameron,
My old Compass had a grease nipple of the gland and all I ever used was bog standard marine grease. Did that for twenty years with no problems. 
rgds
Andrew


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## Classic30 (Aug 29, 2007)

tdw said:


> Cameron,
> My old Compass had a grease nipple of the gland and all I ever used was bog standard marine grease. Did that for twenty years with no problems.
> rgds
> Andrew


Didn't know you had a Compass, A. Good solid boats..

There's a grease nipple on this one (or at least there was.. before it corroded away and is now leaking water into the bilge..  )

Anyways, thanks guys - just wanted to check before I did something stupid.


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## tdw (Oct 2, 2006)

Hartley18 said:


> Didn't know you had a Compass, A. Good solid boats..
> 
> There's a grease nipple on this one (or at least there was.. before it corroded away and is now leaking water into the bilge..  )
> 
> Anyways, thanks guys - just wanted to check before I did something stupid.


Too late for that. 

Damn it all Cameron...you make it so easy for a ratbag like me. 

She was actually a Northerner but its easier to just say Compass. Northerner was the original. Can't remember who built them now but they went broke , Lees redesigned the deck and the Compass 28 was born. Nice old thing but no match for Raven.


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## CalebD (Jan 11, 2008)

*Stern Gland Grease*

Brian, Cameron,
Thanks for shattering my monolithic world view on 'stuffing boxes'. When we bought our keel boat 10 years ago I thought that lubricating the shaft with some oil while on the hard was a good idea while running the engine in gear (both bad ideas for a stuffing box set up it turns out). 
Larger vessels like cruise ships, bulkers, tankers and military vessels must also use a similar system rather than cutting 'flax' pieces to jam into a stuffing box or a dripless shaft gland. 
A little grease will get into the water but at least the prop shaft is lubed if the grease nipple is still there, if you know about it. 
I hope I learn something every day.
Best of luck Cameron.



mitiempo said:


> Caleb
> Some stern glands are designed for grease, either have a grease nipple or a remote greaser. It seems to be common to UK built boats as I have owned 2 that way and have seen it on others. But it was years ago and I am not sure which kind of grease - water pump grease maybe?


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## bljones (Oct 13, 2008)

KY Jelly.

Someone had to say it.


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## mitiempo (Sep 19, 2008)

It would dissolve too fast!


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## JimsCAL (May 23, 2007)

CalebD said:


> Larger vessels like cruise ships, bulkers, tankers and military vessels must also use a similar system rather than cutting 'flax' pieces to jam into a stuffing box or a dripless shaft gland.


Actually, traditionally the arrangement on large ships was a water lubricated bearing and packed gland. Just like many sailboats today. The packing was huge - like 2 inches square in section. The leakage was not just an occasional drip, but a small steam pouring into the shaft alley. Remember we are talking about shaft diamters of 2 feet or so. Most ship today use an oil lubricated bearing with double seals. Don't require the regular adjustment that the packed glands did, but failure of the seals is big problem.


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## Classic30 (Aug 29, 2007)

My stern gland is one of the old-style ones with flax strips and grease.. but it's normally pretty dry. A common problem with these is lack of maintenance - with the grease nipple on the fitting itself way down aft and only slightly accessible on most boats, nobody ever thinks to grease them on a regular basis and more and more water leaks in.

I'm not sure what kind of "regular adjustment" there could possibly be - other than making sure you had the right amount of dripping when the shaft is running, which is little different to any other system? 

Oddly enough, I'm told too much water/not enough grease is actually better for the shaft than the more usual too much grease/not enough water because it's the water flow (not the grease) that keeps the shaft cool. ..it's just not that great for an over-worked bilge pump.


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## rg500 (Jul 11, 2007)

a typical stuffing box is required to leak, 40- 60 drops per minute. Most industrial packings are lubricated from the factory. When the stuffing box goes dry, the lube in the packing is squeezed out and lubes the shaft. A grease nipple on the stuffing box is there to replace any lube that has been used up.

During the winter, when you don't use the boat, pump grease in the box to keep the leakage to a minimum.

During the sailing season, monitor the leakage, at least 30 drops per minute when the shaft is rotating. If the stuffing box feels too hot, loosen the gland follower, when it starts to leak too much, tighten it a little.


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