Hot stuffing gland, part 2.

bumblefish

bumblefish

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Remember my hot gear, stern that is. The stuffing gland was getting extremely hot, last night I unscrewed the nuts and slid the stuffing nut? along the shaft awaiting the predicted dribble of water. Nothing, not a drop. Now assuming that a long period of in-activity has left the grease up the shaft too hard? What can I do? Do I have to get a lift out and sort it all out or is there anyway to try and fix this in the water? Also is it totally unsafe to potter about under engine when the gland is getting too hot hold, including the rubber tubing?
 
I would be very careful if I was you. Taking the gland packing retainer off in the water could have led to the packing blowing inwards and an uncontrollable deluge. Sounds like this gland has been overpacked in the past. The correct type of grease should not solidify. Best to get it out of the water and strip down. Could be other debris in the stern tube as well. I'm assuming this is a flexible stuffing box gland type seal and not a Volvo or aquaseal as someone else suposed. Check also that the slots in the cutlass bearing are not blocked preventing water entering the tube.
 
Hi Bumblefish
Ireckon you have the same set up as Me.
When I removed the Nut as you call it.
Infact I repacked in the water several times earlier this Year.

Hardly any water dripped through and I must have had the gland apart a dozen times.
I had me head stuck right up me rectum trying to figure it out.
In the end I had wear on the shaft and an almost severed stern Tube,
Twas not the actual gland arragement which was the snag!
OK I aint saying this is your prob.
The reason for this message is to mention the fact that no water, well just a dribble entered the bilge.
On beaching later the cutlass log was checked where the intakes are.
No prob there either.
During the re stuffing attemps loads of grease was pumped into the job.
I also stuffed the stuffing box manually each time I fruitlessly re packed!

It sounds like you have a Traditional arrangement not one of the Deep Sea types to Me.
Also look at www.diybob.com
 
Sound's like it needs degunging and repacking to me.
As others have said it can be done while still in the water but I would hesitate to suggest this, unless you have done it before on dry land, there is potential for a fairly large amount of water entering the boat.
Run it up to SYC and put it on the drying posts.
As to running hot, not recommended long term.

Done from memory, IIRC Elizabethans have a standard packing and grease gun arrangement.
 
I have an old fashioned stuffing box like yours. The packing does get quite compressed if over tightened - and that was probably why your stuffing box was getting hot.

If you slid the nut foward when everything was cold, i'll bet the grease had hardened and the packing hadn't yet worked itself much looser.

Why not tighten it up and feel the resistance of the shaft? I tighten mine up until I can feel a slight resistance. The run the engine and motor awhile. Recheck the box and see if it still gets hot. A marine engineer recently told me that if you can put your hand on it and keep it there its 'warm' - not hot. If the grease has solidified it will soften and you'll be okay............
 
Yep I reckon a bit of warmness when run after re pack is ok.
I reccomend tightening just as tight as You can by hand.
Then run whist Tied on.
Tickover in ahead for 10 mins then in astern for a few and eyeball drips and check the job for any sign of heat.
Then tighten, gently spanner tight and repeat the operation.
If happy at this Stage take Her out for a run and observe as before.
I nearly got mine right this way.
I think it is paramount not to overtighten too soon, let the Packing bed in/ settle down.
Next week I launch with a new stern tube , shaft, cutlass bearing and log.
A completely new (the same type) stuffing box and obviously new packing.

My prob was similar.
If too tight too much heat.
If too slack too much water ingress.
However at the time I was peeiing against the wind.
I thought I had it sorted.
On a shake down run (Mobo by the way) of 67 miles all seemed OK.
Untill I touched the putty on entering Portmadoc for the first time.
Wasn,t My falt, twas a dodgy depth sounder /forums/images/graemlins/blush.gif
Until I beached Her I didn't know I had a severed stern tube, worn shaft and stuffing box!
So everything was out of line ta boot!

Next week We shall see! /forums/images/graemlins/ooo.gif
 
Repacking the gland while afloat is not so bad .. I've done it ... just make sure you have new packing cut to size at hand ready ... I reckon over 20 mins or so of no packing - I got nothing more than maybe a litre of water ...

Best is to run up a slip and dry-out if you can ...
 
Absolutely agree with the "in the water" guys. I have an old-fashioned stuffing box and was considering changing it for a deep sea seal, however, then I had a pause for thought- what had been happening for the last nearly 30 years (1978 boat)...
I tweek mine under way - having got rid of the worst of the dribble, I motor off and tighten the nuts by hand, gently, until there is perceptible warmth and minimal dribble. Mine doesn't have a greaser, so I only put a finger full in when the thing is apart once a season. I'm glad I didn't change it.
 
I have had her running now and then unlocked the packing nut, still no water ingress. I was seriously considering running her with the nut un-done to see if I can get anything to flow. I am now at the stage of considering a lift out to check it all out and possibly install a tides marine unit! She has been in the water a year now and could probably do with a good wash and possible new anti-foul anyway!!!
 
The experience from our bearing suppliers in Australia, is that grease does nothing to help the operation of the stern glands and in many cases only serves to cause heat and block water channels in the bearings. Water is a very good lubricant and coolant for the bearings and the stuffing. Grease is not a good conductor of heat. Wet stuffing material is a good sealant, it should drip slightly in use but seal with the shaft stationary.

In Western Australia they have seen virtually no use of grease in stern tubes for over ten years, the UK may be lagging behind a little as grease still seems quite common.
 
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