Length of stern tube

S

Squeaky

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Good afternoon:

I have been annoyed with water in a depression under the prop shaft ever since I bought my boat - a Dufour 29 in 1980 and have tried a number of ways of getting rid of it without success.

I had to crawl in behind the engine again today and discovered there is water there again which I was hoping would not be there having installed a Volvo shaft seal last summer. I don't know where the water came from but it cannot escape because the depression in that area. Ideally I would like it to run forward into the main bilge.

I have just hit on another "bright" idea which involves increasing the length of the stern tube so the the seal is closer to the gear box. Once this was done I could fill in the depression so there would be no depression into which the water could settle.

Is there any rule governing the distance between the end of the stern tube/seal and aft end of the gear box?

Cheers

Squeaky
 
Not sure what you hope to achieve, nor how you would do it - assume the stern tube is just a straight tube. No rule about the distance, except that you need enough for the engine to move back and forward as you go in and out of gear plus space to get your seal on with the engine in place. Be aware that moving the seal forward may put it above the waterline which will starve the seal of cooling water. If there is sea water in that location it is either leaking from the clamp of the seal to the tube, or between the tube and the hull.
 
Confirming my reputation as a bodger-
Try an osmotic syphon ..
That is, lay a rag or piece if kitchen roll from a point below the level of water in the depression to the run into the bilge.
Takes a while but works beautifully.
please send me the £500 I've just saved you. ;)
Nick
 
alahol2 said:
Is it feasible to clean out the depression and pour in a couple of layers of resin (or even concrete)?
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Good morning:

No, I have built up or filled the depression as much as I can - any more will reach the forward end of stern tube which is why I am considering increasing the length of the tube as this will move the forward end higher although closer to the gear box.

Having re-considered the matter I have decided to put off the project until the next time I slip as I have began to wonder exactly where the water comes from. It is entirely possible that the water that is there now came in somehow from rain during the winter. I will clear out the water and keep an eye on it over the summer.

Over the years I have blamed leakage from the seal however I have a new Volvo seal so will give it a chance and live with the problem for another year.

At least the Volvo seal hasn't split and filled the bilge with water as the two PSS seals did.

Cheers

Squeaky
 
the volvo seal is water lubricated so it needs to be below the water line. Most other seals are the same. But the volvo seal should not leak any water anyway. You have something wrong
 
Bosun Higgs said:
the volvo seal is water lubricated so it needs to be below the water line. Most other seals are the same. But the volvo seal should not leak any water anyway. You have something wrong
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Exactly. Is there enough grease in the volvo seal? Is the alignment OK? Is there any rough surface (rust?) at the shaft where it goes through the volvo seal? These seals lasts for years and don't leak.
 
ingress between the tube & hull
img74.gif
 
are you sure its from the stern seal the PPS and Volvo shoulnt leak, i get water under my stern seal but its rain water coming in from somewhere.. tast the water and see if its salt
 
bert49uk said:
are you sure its from the stern seal the PPS and Volvo shoulnt leak, i get water under my stern seal but its rain water coming in from somewhere.. tast the water and see if its salt
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Good afternoon:

I know that seals are not supposed to leak however I can promise you that PSS seals not only leak, they tear and rip open. Please see post http://www.ybw.com/forums/showthread.php?289854-PSS-Shaft-Seal-problems beginning with post 39 for details of my experience with not one but two PSS seals.

I have decided to adopt the "wait and see" approach to this new seal as it is easier to adopt this approach than it is to worry about lengthening the stern tube now having already slipped to apply anti-fouling for this season.

Thanks for all the comments.

Cheers

Squeaky
 
Come on Squeaky, it would appear only you had a problem with the PSS, and that from a possible ‘Copy’ seal. I fitted one this year and from fitting not a drop, I’m very pleased with it like most owners. I’m sorry you had problems but I’m starting to get a bit fed up with you coming on every time anyone mentions a PSS seal
 
bert49uk said:
Come on Squeaky, it would appear only you had a problem with the PSS, and that from a possible ‘Copy’ seal. I fitted one this year and from fitting not a drop, I’m very pleased with it like most owners. I’m sorry you had problems but I’m starting to get a bit fed up with you coming on every time anyone mentions a PSS seal
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Good afternoon:

Unfortunately it was I that suggested the seals might be fakes because I didn't want to believe that products from a supposedly respected company could fail however having sent the seals to Seaview in France it were established they were not copies.

You can rest assured that I will be posting damning comments concerning PSS seals and their refusal to own up or to accept responsibility for their products as long as I am a member of this forum and having posting rights. You have a choice: either get used to reading my negative comments or avoiding my posts on PSS seals or any mention of these seals.

I am glad that you are happy with your seals and their performance but so was I until they failed catastrophically. Wait until you spend the night sitting up pumping every 20 minutes in order to keep your yacht afloat before commenting on my experience - that is, of course, if you happen to be lucky enough to be on board to discover the failure of the seal.

The cost of the seal was repaid by the local supplier and after that I was concerned to discover if the seals were fakes or to learn how and why I was supplied with the seal I was. However I was met with what I felt was a "stone wall" by both Seaview (European distributors) and PYI who seemed determined not to respond to my questions and instead created many "red herring" leading the discussion away from the main point. In the end I was told not to bother them again and to take action against the local supplier which anyone familiar with the local court system will know is totally useless until you have lots of money and time. I was not interested in money, just an explanation. Fortunately they did not obtain a "stalking" court order against me.

Cheers

Squeaky



P.S. PM me your e-mail address and I will pass you copies of all the messages I exchanged with Seaview and PYI and you can judge for yourself. In fact this offer applies to anyone interested in the subject.
 
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I think that you might be getting a little too concerned about little leaks, the bilge is where the water is supposed to collect, and your worrying yourself too much about little amounts of water, my boat collects some water over a month or so, but I pump it out and use the bilge pump and some pampers to soak it up dry. its just normal boaty stuff to do. my boat wont sink as there is no problem with the stuffing seal (traditional), its just accumulation of condensation, rain water etc.....
 
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