Weeping around the stern gland... What action?

[Boater Sam]

Boater Sam - if you wish to send me a decent picture of a narrow boat stern gland I will gladly add it to the website.
[/QUOTE]
I have this one from the fit out pontoon. attached.

 

[vyv_cox]

Boater Sam - if you wish to send me a decent picture of a narrow boat stern gland I will gladly add it to the website.

I have this one from the fit out pontoon. attached.View attachment 95309
[/QUOTE]
Thanks, will add it when time allows.

 

[Captain Crisp]

Evening, Poignard and all,
I'm ashore now and had a good poke around yesterday and a close study of the excellent images on Vyv Cox's website.
Couple of observations:

• The exterior bearing holder seems very sound
• The stern tube was fairly loose and I was able to tighten it quite considerably clockwise (looking aft)
• There seems to be a fair amount of grease escaping around where the stern tube meets the stern gland

Any thoughts!? I'm imagining that the weeping leak was escaping around where the stern tube was too loosely attached to the exterior bearing holder. Will tightening alone solve that, or do I need to add some kind of sealant? Also, I'm a bit confused about the grease around the front of the stern tube - is that a bad sign? Presumably it's squeezed out between the threads where the tube meets the stern gland.
Many thanks,
Crisp

 

[vic008]

Same problem here. An unusual inner gland with 4 lagbolts. Bottom two loose as, wonder is that due to wet timber? Plan on longer (4") lagbolts set in Emerkit underwater epoxy putty. Then at next haulout, outboard stern gland housing off and new sika under it.

 

[LittleSister]

Try an arm round the shoulders, a gentle hug, saying 'There, there', and making it a cup of tea.

 

[Poignard]

Evening, Poignard and all,
I'm ashore now and had a good poke around yesterday and a close study of the excellent images on Vyv Cox's website.
Couple of observations:

• The exterior bearing holder seems very sound
• The stern tube was fairly loose and I was able to tighten it quite considerably clockwise (looking aft)
• There seems to be a fair amount of grease escaping around where the stern tube meets the stern gland

Any thoughts!? I'm imagining that the weeping leak was escaping around where the stern tube was too loosely attached to the exterior bearing holder. Will tightening alone solve that, or do I need to add some kind of sealant? Also, I'm a bit confused about the grease around the front of the stern tube - is that a bad sign? Presumably it's squeezed out between the threads where the tube meets the stern gland.
Many thanks,
Crisp

After cleaning the threads at either end of the sterntube and the female threads in the outer bearing and stern gland you'll need to apply a thread sealant .

I used Loctite 572 in 2008 and it has not leaked since.

LOCTITE 572

 

[MonniotC]

"Weeping around the stern gland... What action?"

Dry your eyes and man up.

 

[Akestor]

Evening, Poignard and all,
I'm ashore now and had a good poke around yesterday and a close study of the excellent images on Vyv Cox's website.
Couple of observations:

• The exterior bearing holder seems very sound
• The stern tube was fairly loose and I was able to tighten it quite considerably clockwise (looking aft)
• There seems to be a fair amount of grease escaping around where the stern tube meets the stern gland

Any thoughts!? I'm imagining that the weeping leak was escaping around where the stern tube was too loosely attached to the exterior bearing holder. Will tightening alone solve that, or do I need to add some kind of sealant? Also, I'm a bit confused about the grease around the front of the stern tube - is that a bad sign? Presumably it's squeezed out between the threads where the tube meets the stern gland.
Many thanks,
Crisp

A loose stern tube is not normal. The external bearing holder is screwed at the aft threaded part of the stern tube and is also supported by the 2 machine bolts through the hull(?). So any leakage could occur via the stern tube threads or/and the through-hull machine bolts. Disassembling and re-sealing bolts and stern tube threads are the way to go.

 

[Captain Crisp]

You would have to remove the rearmost bearing ( the cutless bearing and its housing.), clean up everything, then seal the threads wherethe bearing ousing screws onto the sterntube and apply a bedding compound to the flange where it is attached to the hull.

I have done it on my Twister and it was a straightforward job.

I may have pictures at home but I will be in France until the weekend.

Hi Poignard,
Hope all's well. What ointment would you recommend for sealing the housing to the stern tube? And what 'bedding compound' for when I put the housing back onto the hull?
Hoping to attempt this on Thursday!
Many thanks,
Crisp

 

[rotrax]

You would have to remove the rearmost bearing ( the cutless bearing and its housing.), clean up everything, then seal the threads wherethe bearing ousing screws onto the sterntube and apply a bedding compound to the flange where it is attached to the hull.

I have done it on my Twister and it was a straightforward job.

I may have pictures at home but I will be in France until the weekend.

The OP has a canal narrowboat.

In my direct and quite extensive experience of these vessels the stern tube is welded in place. All mine have been anyway.

I suspect a really good clean up in the area might reveal the cause.

In our canalboating life a guy was doing exactly that when he enlarged the hole so much the bilge pump could barely keep up.

His hull was rotten and badly corroded due to galvanic action. The steel tube/ steel hull/canal water interface made a galvanic cell which tranfered material from the hull to the tube, causing the leak.

Galvanic protection was missing - no anodes at all,

The boat was saved by draining the short pound after stern hauling the boat into a cattle drink. The welder attended and made a temporary repair untill the boat was dry docked at Banbury.

 

[Captain Crisp]

The OP has a canal narrowboat.

In my direct and quite extensive experience of these vessels the stern tube is welded in place. All mine have been anyway.

I suspect a really good clean up in the area might reveal the cause.

In our canalboating life a guy was doing exactly that when he enlarged the hole so much the bilge pump could barely keep up.

His hull was rotten and badly corroded due to galvanic action. The steel tube/ steel hull/canal water interface made a galvanic cell which tranfered material from the hull to the tube, causing the leak.

Galvanic protection was missing - no anodes at all,

The boat was saved by draining the short pound after stern hauling the boat into a cattle drink. The welder attended and made a temporary repair untill the boat was dry docked at Banbury.

I'm the OP and last time I looked there was a big stick with a couple of white flappy things hanging off!

(Thanks anyway! ?)

 

[penfold]

I'm the OP and last time I looked there was a big stick with a couple of white flappy things hanging off!

(Thanks anyway! ?)

There's a lot of it about(posting without reading and comprehending that is).

 

[penfold]

Hi Poignard,
Hope all's well. What ointment would you recommend for sealing the housing to the stern tube? And what 'bedding compound' for when I put the housing back onto the hull?
Hoping to attempt this on Thursday!
Many thanks,
Crisp

Lifecalk between the flange and the hull would be my preference, but as long as it's a flexible waterproof bedding compound most things will do. For the threads on the sterntube betwixt tube and the cutlass bearing holder I'd put something non-setting like Boss White, but again there are many choices that would do just as well.

 

[Poignard]

Hi Poignard,
Hope all's well. What ointment would you recommend for sealing the housing to the stern tube? And what 'bedding compound' for when I put the housing back onto the hull?
Hoping to attempt this on Thursday!
Many thanks,
Crisp

All's well, thank you. And I hope all's well with you.

According to my notes:

I last had the cutless bearing housing off in 2002. When I re-fitted it I sealed the mating threads on the sterntube/cutless bearing housing with Hemetite Gold (non-setting thread-sealer). The joint between the sterntube/cutless bearing housing and the 'sternpost' I sealed with Sikaflex 291. It has not leaked since.

I last had the stuffing box/bearing off in 2008. When I refitted it I sealed the threads with Loctite 572 . It has not leaked since.

I'm not sure Hemetite Gold is still available but I would be quite happy to use Loctite 572 instead.

I would also be happy to use CT1 as an alternative to Sikaflex 291.

There are many other types of sealants available but those I used were what was available at the time, where I happened to be, and they have done the job.

 

[Poignard]

The OP has a canal narrowboat.

In my direct and quite extensive experience of these vessels the stern tube is welded in place. All mine have been anyway.

I suspect a really good clean up in the area might reveal the cause.

In our canalboating life a guy was doing exactly that when he enlarged the hole so much the bilge pump could barely keep up.

His hull was rotten and badly corroded due to galvanic action. The steel tube/ steel hull/canal water interface made a galvanic cell which tranfered material from the hull to the tube, causing the leak.

Galvanic protection was missing - no anodes at all,

The boat was saved by draining the short pound after stern hauling the boat into a cattle drink. The welder attended and made a temporary repair untill the boat was dry docked at Banbury.

I'm sure the OP, Captain Crisp, has a Twister sloop, (one of the finest small yachts ever to grace the water) and that is what he is asking about.

For all I know, he may have a steel canal boat as well but my advice applies only to his Twister.

 

[Captain Crisp]

No steel canal boat as yet...

Many thanks for this!
Crisp

 

[Tranona]

Another vote for Lifecaulk although this is difficult to source these days so suggest Arbokol 1000. The important thing is that it should be non adhesive - both of these are Polysulphide . Really no need for anything other than a smear of sealant on the thread. It can't unscrew as it is locked into place.

 

[rotrax]

I'm the OP and last time I looked there was a big stick with a couple of white flappy things hanging off!

(Thanks anyway! ?)

OOPS!

 

[Captain Crisp]

All's well, thank you. And I hope all's well with you.

According to my notes:

I last had the cutless bearing housing off in 2002. When I re-fitted it I sealed the mating threads on the sterntube/cutless bearing housing with Hemetite Gold (non-setting thread-sealer). The joint between the sterntube/cutless bearing housing and the 'sternpost' I sealed with Sikaflex 291. It has not leaked since.

I last had the stuffing box/bearing off in 2008. When I refitted it I sealed the threads with Loctite 572 . It has not leaked since.

I'm not sure Hemetite Gold is still available but I would be quite happy to use Loctite 572 instead.

I would also be happy to use CT1 as an alternative to Sikaflex 291.

There are many other types of sealants available but those I used were what was available at the time, where I happened to be, and they have done the job.

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

 

[Akestor]

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

I think you should seal the threads once you got it so far. Is this an anode or the prop nut at the end? If it is the nut it should have a split pin so you should remove the pin to undo the nut and pull the prop back. It's not a difficult job!