Flexible Stuffing Box maintenance

Aeolus

Aeolus

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I have what I believe is called a flexible stuffing box. It's on a Seamaster 925 sailing boat and probably dates from the original 1978 build.

This past summer the drip rate increased from 1 per minute or less to one every 10 seconds which, whilst unlikely to cause me to sink, means that I have to pump out the bilge much more often.

Now that the boat is out of the water I undid the gland nut but cannot see where or how to add or replace any 'stuffing'. There doesn't seem to be any 'stuffing' there currently.

Should this type of seal actually have any stuffing other than the grease that is pushed into it?

Thanks
20151116_150348.jpg20151116_150414.jpg
 
I have backed off the locking nut and unscrewed the large nut - there is no stuffing there and there is only maybe a 3 or 4 mm depth and a couple of mm height that any packing could fit into.

The yard that re-engined the boat 4 years ago presumably either didn't think any stuffing was needed or they forgot - but it has been fine until this past summer
 
was there a type of collet that the outer nut pushed against

packing4.JPG


http://coxengineering.sharepoint.com/Pages/Sternglands.aspx
 
I don't think so. If there is anything like the blue collet(?) then it has been pushed into the gland so that the collet's left end is a couple of mm into the gland itself and there is no obvious way of removing it.
 
I've looked - if the blue top hat-like sleeve exists, then it has been pushed into the gland so that it's not obvious how to pull it out. - is that what is supposed to happen?
 
Aeolus said:
I've looked - if the blue top hat-like sleeve exists, then it has been pushed into the gland so that it's not obvious how to pull it out. - is that what is supposed to happen?
Click to expand...
The top hat flange is designed for that not to happen.It will bottom out on the tube

this is similar to what i have ( with out all the crud )

water%20lub.jpg
 
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I guessed that that would be the case - so either a sleeve without a rim was used or it works on a different principle all together. Interestingly there is a picture of exactly 'my' stuffing box on Viv's website but only as an example of how the flexible tube can fail.

I wonder whether the packing & sleeve would be pushed out if I added grease with the gland nut undone. Does this sound likely?
 
It must have packing in there or water would be pouring in. The grease is incidental. The seal is made by the packing being compressed against the shaft. Clean it all up and use a screwdriver to pick away at the packing. However, if it were me I would want to at least replace that hose as it looks past its sell by date, or even better replace the whole assembly with a more modern type.
 
With the nut backed off and away from the gland, take a hook or small screwdriver and "hawk" out any soft material, if you only hit a metallic sounding surface then indeed you have no stuffing in the fitting, and your joint has remained dry due to grease and very very good luck. Looking at the picture you have lots of free thread to allow the sealing nut to advance and squeeze the non existing packing! LOL
 
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Inside the gland, the entire width between the shaft and the gland itself does seem to be metallic or it could possibly be a very hard plastic - for sure there is no soft material that could be picked out.
 
Tranona said:
It must have packing in there or water would be pouring in. The grease is incidental. The seal is made by the packing being compressed against the shaft. Clean it all up and use a screwdriver to pick away at the packing. However, if it were me I would want to at least replace that hose as it looks past its sell by date, or even better replace the whole assembly with a more modern type.
Click to expand...
Is "Modern " better
 
Perhaps your packing is so well compressed and hardened that you do not realise it is in there. It can take on a slightly shiny metallic appearance as the collar compresses it.
 
If that stern gland was on my boat, my main priority would be to replace that bulging rubber sleeve. It's the only thing stopping the boat from flooding, and looks in v. poor condition.
Doing this would involve the gland being removed from the shaft, the packing arrangement could then be examined in better detail.
 
It's not jammed in the nut is it? The nut doesn't seem to have enough depth for a few turns of packing as there should be, when the nuts backed off is the face of the tube tapered towards the shaft, ie for the packing to tighten round the shaft when the nuts tightened.
 
Don't know if it is tapered - I don't think it is but will check when I'm next at the boat. Presumably if it isn't then that suggests there is something inside the gland e.g. compressed packing.
 
Aeolus said:
I have backed off the locking nut and unscrewed the large nut - there is no stuffing there and there is only maybe a 3 or 4 mm depth and a couple of mm height that any packing could fit into.
Click to expand...

How does the "3 or 4 mm depth" compare with the length of the nut itself? I would suggest that you dig inside the nut at the inner face that presses against the main body of the gland. There is a 'special' tool for doing this and it looks like a corkscrew, however, you can still manage with a sharpened bit of steel wire... and a lot of fiddling.
packingchest.jpg
 
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