Advice and warning beneteau stern tube

[raymondmcm]

I have a 1986 beneteau 325 and as part of refitting I just happened to notice that it has a brass stern tube which was completely dezincified and would most likely failed catastrophically very soon had i not noticed it. A gentle tap shattered the end of it !

Anyone had any similar experiences and maybe some advice on the best repair method ? Brass tube, stainless tube or fibreglass tube ?

 

[Norman_E]

I am surprised nobody has replied on this. I don't know the Beneteau setup, but on my Jeanneau the only bit of stern tube that matters is the short piece inside the boat that the rubber bellows of the stern gland clamps on to. If this is failing its going to be a bit of an awkward job getting the tube out, though I suspect that on my boat the metal tube does not extend very far in. Certainly there is nothing visible on the outside.
An important issue if you have a Volvo or Radice stern gland is the tube outer diameter. Fibreglass tube is good but tends to be thick walled, so can you get a piece the correct outside diameter that still has enough clearance inside for the shaft, allowing for engine movement on its mounts when running? My own choice would be to try and find copper tube of the right size, but stainless would also be reasonably long lived. Common brass, immersed in water with no anode attached was a recipe for the sort of failure that has happenned.

 

[raymondmcm]

Thanks, I'd suggest anyone with a boat of similar vintage and design have a good look.

It is, as you describe a very short bit of tube protruding from the fibreglass that the rubber clamps onto.

It appeared absolutely fine but i dropped something and a bit just broke off and further investigation showed it was well dezincified.

From what i see it's a brass funnel type thing glasses to the hull.


I've removed some fibreglass and i will cut back the tube and butt join a piece of stainless or fibreglass tube and glass it over.

 

[Heckler]

I have a 1986 beneteau 325 and as part of refitting I just happened to notice that it has a brass stern tube which was completely dezincified and would most likely failed catastrophically very soon had i not noticed it. A gentle tap shattered the end of it !

Anyone had any similar experiences and maybe some advice on the best repair method ? Brass tube, stainless tube or fibreglass tube ?

My 1999 Bene 381 has a stainless tube outside for the cutlass bearing and the inside is fibreglass tube
Stu

 

[GD_Chi]

I have a 1985 Beneteau First 29 and had the same problem 3 years ago.
I removed the old Volvo seal in preparation for changing the cutless bearing (I have found that the easiest way is to remove the gearbox and move the shaft forwards) and found that the tube was cracked lengthways at the top and partially around the circumference. If I remember correctly one piece of the tube fell off and another broke off with light finger pressure.
The solution was to cut out the old tube and surrounding GRP completely and glass in an epoxy tube.
The tube and an RMTA shaft seal were bought from Sillette-Sonic, www.sillette.co.uk who were very helpful with advice. They machined the outside of the tube to fit the seal and it was professionally glassed in by a local GRP specialist. Overall it is a very neat job and one would never know that it was not original.
The tube details are quote: 1 1/4" x 1 3/4" x 2 ft long epoxy tube, with one end machined to 42mm for 25 x 42 RMTA shaft seal.
The machining has ridges (rather than being smooth) so the shaft seal grips well.
The RMTA seal, also known as Radice, looks identical to the Volvo one except for an integral grease hole/plug and an integral vent tube (my boat had a vent built into the stern tube).
As suggested above there is much less clearance between the tube and the shaft than before but that has not caused any problems in 3 years of use. However it does mean that the tube has to be bonded in very accurately.
Hope this helps.
Guy

 

[raymondmcm]

Thanks for that

I was speaking to sillette earlier today after going round and round almost every supplier who didn't stock grp tube
!!

 

[hallberg36]

Interested in your post as I have a similar problem with my own boat based in Portsmouth (as posted on here last year). I intend to follow your example and have the GRP cut away to enable the stern tube to be replaced as gaining access inside, and removing the shaft & stern tube is not straightforward. Can you let me know who did the GRP work, as I'm struggling to find a local company enthusiastic to do this job, probably as it needs to be done here in Port Solent.

 

[raymondmcm]

Sorry cannot help, mine was done in Malahide in Ireland. Super job and done very quickly at a busy time of year.

I informed beneteau of this issue, and they told me they never used brass sterntubes and that someone had removed the fiberglass tube fitted in the factory and replaced it with a brass one LOL

They also did a super job of matching the flowcoat and ageing it to an exact match of the original !!!

 

[Joe Beneteau 423]

Interested in your post as I have a similar problem with my own boat based in Portsmouth (as posted on here last year). I intend to follow your example and have the GRP cut away to enable the stern tube to be replaced as gaining access inside, and removing the shaft & stern tube is not straightforward. Can you let me know who did the GRP work, as I'm struggling to find a local company enthusiastic to do this job, probably as it needs to be done here in Port Solent.

Hi did you find someone to do this work for you? I have a similar stern tube issue and struggling to find someone who has done such a repair before.

 

[GD_Chi]

Mine, the First 29, was done by the glass fibre person at Emsworth Chandlery. Unfortunately they are no longer in business and the person who actually did the work would have retired by now. It's a shame as I still have the boat and it is all OK 8 years on.
I have seen your other post about the Beneteau 423 but the First 29 has a different arrangement with a P bracket. There is just a short stern tube to mount the seal and both the original and the repair were fully glassed with matt and resin. There aren't any blobs of thickened resin/epoxy as shown in your picture.
Sorry that I can't be more help.

 

[Joe Beneteau 423]

Thank you for your reply. That's a shame they arent still there. Interesting to know of the different arrangement with a P bracket, I will keep searching, hopefully someone has seen something similar.

 

[hallberg36]

Interested in your post as I have a similar problem with my own boat based in Portsmouth (as posted on here last year). I intend to follow your example and have the GRP cut away to enable the stern tube to be replaced as gaining access inside, and removing the shaft & stern tube is not straightforward. Can you let me know who did the GRP work, as I'm struggling to find a local company enthusiastic to do this job, probably as it needs to be done here in Port Solent.

Hi, I had the work done by Desty Marine based on the Hamble who did an excellent job and were also recommended by Hallberg-Rassy UK, and my insurers. I would have no hesitation in using them again.... hope this help.

 

[Arcady]

I have a 1986 beneteau 325 and as part of refitting I just happened to notice that it has a brass stern tube which was completely dezincified and would most likely failed catastrophically very soon had i not noticed it. A gentle tap shattered the end of it !

Anyone had any similar experiences and maybe some advice on the best repair method ? Brass tube, stainless tube or fibreglass tube ?

Yes! On a 1974 Fjord MS33. See SOHVI: Stern tube failure

 

[Joe Beneteau 423]

Interested in your post as I have a similar problem with my own boat based in Portsmouth (as posted on here last year). I intend to follow your example and have the GRP cut away to enable the stern tube to be replaced as gaining access inside, and removing the shaft & stern tube is not straightforward. Can you let me know who did the GRP work, as I'm struggling to find a local company enthusiastic to do this job, probably as it needs to be done here in Port Solent.

Hi there, I think I have a similar issue. Just wondered if you found a company to complete the work out whether it fixed the issue? I have another post with some photos of my stern tube issue that I posted today. I wonder if the internal

Hi, I had the work done by Desty Marine based on the Hamble who did an excellent job and were also recommended by Hallberg-Rassy UK, and my insurers. I would have no hesitation in using them again.... hope this help.

That's really useful. I will give them a shout. Thanks very much.