Weeping around the stern gland... What action?

Tranona

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As I suggested earlier the thread really does not need any specific sealer. The seal to stop water getting into the boat is around the tube and the face of the hull. Clean up both of the faces, put a ring of polysulphide around where the tube enters the hull and coat the face of the hull side with sealant. Screw up the housing until it is firm and you can get the locking screws in, remove excess sealant - job done.
 

Captain Crisp

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As I suggested earlier the thread really does not need any specific sealer. The seal to stop water getting into the boat is around the tube and the face of the hull. Clean up both of the faces, put a ring of polysulphide around where the tube enters the hull and coat the face of the hull side with sealant. Screw up the housing until it is firm and you can get the locking screws in, remove excess sealant - job done.

Thanks, though I think water was escaping from within the tube via the thread connection to the holder. Possibly simply because it wasn't tightly screwed on enough . The holder itself seemed very well bonded to the hull, so I don't think water was getting in around the sides. But I will certainly do what you're saying as well.
 

Poignard

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As I suggested earlier the thread really does not need any specific sealer. The seal to stop water getting into the boat is around the tube and the face of the hull. Clean up both of the faces, put a ring of polysulphide around where the tube enters the hull and coat the face of the hull side with sealant. Screw up the housing until it is firm and you can get the locking screws in, remove excess sealant - job done.
But there is always water inside the stern tube and if the threads are not sealed water will escape through the unsealed threads into the boat.

I have had his problem at the forward end of the sterntube when the thread sealant failed due to its becoming brittle with age.
 

Poignard

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Hi, I got the cutless bearing housing undone, unfortunately, there wasn't enough space between it and the prop to access the threads. I can just see them through a 1mm gap... I suppose I could try and syringe some thread seal through the gap? Or do you think I should take the prop off and do it properly? Not sure how simple taking a prop off is...?
Thanks!
Crisp
View attachment 112641
As it's the sort of job I wouldn't want to have to do twice, I would be inclined to give the whole assembly a thorough overhaul while our sailing is so restricted.

That would include removing propeller, propshaft, outboard bearing, inboard bearing and stuffing box, stern tube.

Then you can inspect everything and replace anything suspect or worn.

Re-assemble, working from aft to forward, sealing the threads with thread sealant and the interface between outboard bearing flange and deadwood with CT1 or similar.
 

rogerthebodger

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I take it this is where the weeping is coming in.

If so you need to clean this up so we can see exactly the sealing arrangement and so the exact point where the weep is coming from.

What yoy have done on the outside will not stop the leak but if the bearing is loose it will need fixing to stop it rotating in the stern tube.
 

Captain Crisp

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As it's the sort of job I wouldn't want to have to do twice, I would be inclined to give the whole assembly a thorough overhaul while our sailing is so restricted.

That would include removing propeller, propshaft, outboard bearing, inboard bearing and stuffing box, stern tube.

Then you can inspect everything and replace anything suspect or worn.

Re-assemble, working from aft to forward, sealing the threads with thread sealant and the interface between outboard bearing flange and deadwood with CT1 or similar.
Assuming I don't discover a horror.... how long should that take me do you think? I have an ever extending to-do list!
Thanks so much for all this help,
Crisp
 

Poignard

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Assuming I don't discover a horror.... how long should that take me do you think? I have an ever extending to-do list!
Thanks so much for all this help,
Crisp
Ça dépend! :D

On how easy things come apart and whether you need any replacement parts.

Sometimes the propeller can be difficult to shift and also the gearbox coupling. As you have a 2-bladed propeller you could remove the gearbox coupling , turn the rudder to one side and pull the propshaft out with the propeller attached and remove the propeller on a bench.


If you want a quick job you could just remove the propeller, take off the outboard bearing, clean its threads thoroughly and those on the propshaft as best you can, then apply thread sealant (I used Loctite 572) and screw it back on with some CT1 or Sikaflex on the flange.
 

WoodyP

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But there is always water inside the stern tube and if the threads are not sealed water will escape through the unsealed threads into the boat.

I have had his problem at the forward end of the sterntube when the thread sealant failed due to its becoming brittle with age.
Me too. Got into Wells Harbour one night with a big leak. Bit of a panic, until I found I could rotate the stern tube and screw it tight to stem the leak. It worked until I could do a permanent fix, in the water, with sealant on the threads.
 

Tranona

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But there is always water inside the stern tube and if the threads are not sealed water will escape through the unsealed threads into the boat.

I have had his problem at the forward end of the sterntube when the thread sealant failed due to its becoming brittle with age.
But it can't get into the boat if the seal around the tube where it enters the hull is properly done. A strand of caulking cotton might help there before squirting the sealant. Really does not matter if the threads are not sealed. Had exactly the same arrangement on my Eventide and had the housing off several time in the near 40 years I owned it (engine changes, new shafts, converting to cutless bearing etc) and never put any sealer on the threads specifically as they only locate the housing on the tube - they don't even need to be tight as you can only lock in 2 points 180 degrees apart. The seal is where the tube goes into the hull and the front face of the housing.
 

Poignard

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But it can't get into the boat if the seal around the tube where it enters the hull is properly done. A strand of caulking cotton might help there before squirting the sealant. Really does not matter if the threads are not sealed. Had exactly the same arrangement on my Eventide and had the housing off several time in the near 40 years I owned it (engine changes, new shafts, converting to cutless bearing etc) and never put any sealer on the threads specifically as they only locate the housing on the tube - they don't even need to be tight as you can only lock in 2 points 180 degrees apart. The seal is where the tube goes into the hull and the front face of the housing.
I can't agree with that.

This is a screwed pipe joint and such joints are made watertight by applying sealant to the threads.

Otherwise what is to prevent water seeping along the threads and out into the boat?
 

Captain Crisp

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Hi - got the prop off easily enough... Then pulled the bearing housing off. Couple of questions...
  1. The cutlass bearing looks knackered - how do I get it out and what size new one should I buy? The shaft is 1".
  2. I can't seem to get the stern tube to unscrew out of the bulkhead where the tube meets the inner stern gland. It turns about an inch, but no further. I'm not too fussed as it wasn't leaking at that end, but any thoughts as to why won't it come out...?
  3. The tapered prop nut came off rather easily and doesn't have a pin or anything to keep it in place. It seems to have a small threaded opening on the point of its tapered end. Should something be in there?
Thanks!
Crisp


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penfold

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Hi - got the prop off easily enough... Then pulled the bearing housing off. Couple of questions...
  1. The cutlass bearing looks knackered - how do I get it out and what size new one should I buy? The shaft is 1".
  2. I can't seem to get the stern tube to unscrew out of the bulkhead where the tube meets the inner stern gland. It turns about an inch, but no further. I'm not too fussed as it wasn't leaking at that end, but any thoughts as to why won't it come out...?
  3. The tapered prop nut came off rather easily and doesn't have a pin or anything to keep it in place. It seems to have a small threaded opening on the point of its tapered end. Should something be in there?
Thanks!
Crisp


View attachment 113073
2. It may well leak now you've disturbed it.
3. the thread in the end is for a locking screw or bolt.
 

penfold

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The cutlass bearing can be removed with a puller; make your own with washers and threaded rod, or buy a ready-made one, then use the puller to put in the new bearing. Alternatively you could get it pressed out and a new one pressed in by a workshop with a press.
 

Tranona

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I think you will find that is a rubber bush rather than a cutless and is shorter than a standard cutless (which is 4"). You may need the housing machined to take a standard cutless bearing, or you could have a composite bearing machined to fit the housing. Whereabouts are you based as worth consulting a marine engineer as to the best way of replacing the bearing. h4marine.com will make you a composite bearing if you decide to go down that route. (the owner sometimes posts here)

As penfold suggests, pity you tried to unscrew the tube as there is no need ever to move this unless totally replacing it. The inboard housing should be sealed in a similar way to the outboard and the way to remove the tube is to take the inboard housing off and knock the tube out. Hopefully you won't get a leak there if you screw the tube back up. The way to stop water getting into the boat up the side of the tube is, as I suggested earlier ensure that the gap around the tube as it goes into the hull is sealed. When I did mine I wrapped a strand of caulking cotton coated in sealant into the gap and then plenty of sealant on the face and inside the end of the housing. That way even if there is (unlikely) weeping up the threads it won't go into the boat.
 

Poignard

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Here is a firm that makes cutless bearings ( Countrose Bearings | About Us Countrose Bearings | Product Standard Sizes ).

The one in my Twister is I/D 1" O/D 1-1/4" L 2-3/8". I was lucky in finding one Ffoulkes Chandlery Barge, Bursledon.

The cutless bearing may be a fiction fit or there may be two grubscrews in the side to remove first.

Then you can pull it out using an arrangement of steel studding, nuts, large washers and suitable diameter tube. Another way, if you are careful, is to saw through the sides of the cutless bearing along its length but avoiding cutting into the housing. If it is like mine it is only 2-3/8" long.

The new one can be pressed in in a large vice, with suitable protection from the jaw teeth, or pulled in with studding , nuts and large washers.
 

Captain Crisp

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I'm afraid this is becoming the thread that refused to die.
Any advice on getting the stern tube out of the stern gland? It turns about an inch and then refuses to move... It's completely free at the propeller/deadwood end, so I'm imagining that there may be something trapping it where it screws onto the stern gland. Will it help if I unscrew the stern gland forward of the supporting bulkhead? Should I take the shaft out first? Also might it be reverse threaded for some reason?
Here's an old picture showing the stern tube meeting the bulkhead where the stern gland sits... Not that easy to access... Although it is a bit cleaner now!
Thanks,
Crisp
Screenshot_20210418-214054_compress1.jpg
 

penfold

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Can you get a pic of what's hiding behind those hoses? How is the tube fastened to that bulkhead? Unlikely that the sterntube has a left hand thread, although anything's possible I suppose.
 

Captain Crisp

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Can you get a pic of what's hiding behind those hoses? How is the tube fastened to that bulkhead? Unlikely that the sterntube has a left hand thread, although anything's possible I suppose.

Not till the weekend, sadly! The stern gland appears to be bolted onto the forward side of the bulkhead.
 

Tranona

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Not till the weekend, sadly! The stern gland appears to be bolted onto the forward side of the bulkhead.
That is a pretty standard set up. The tube is held in place by the stuffing box housing screwed onto the tube and attached to the little bulkhead with the 2 locking screws (or they might be bolts with nuts on the aft face - difficult to tell from the photo). Exactly the same as the aft end where the tube is located by the bearing housing screwed on and locked to the hull.

I am still puzzled by why you want to remove the tube, but if you do then the procedure is to undo the inner and outer bearing housings and pull the tube out. This will of course break the watertight seal where the tube goes through the deadwood in the hull. Often the aft end is glassed in so it does not leak and is permanently fixed in place. However the fact that you can turn the tube suggests it is sealed with a flexible sealant at the aft end which has probably failed.

This will give you a good idea of how it works

sillette.co.uk/catalogue.pdf#page=4
 
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