I would go for option 3 unless time and money are available in larger than normal quantities. Should look really tidy once complete.

The knead it idea is good.

Stating the B$$#^** obvious, however I would want to leave the knead it repair for a good week + to be sure that it has made a seal. Once the glass is in, its in. You don't want pools of water sitting behind the glass cover long term.

Thanks Ramona and Fiesta. I have just returned from the boat yard and we are doing exactly as suggested.

The old tube had corroded in the section that is exposed in the bilge forward of the bulkhead enclosing the concrete. The stainless tube has been cut off just behind the leak, just forward of the bulkhead, and a glass tube pushed over the remaining piece of exposed stainless tube, bonded and epoxied. This piece of glass tube has a bearing in it to support the forward end of the shaft. The whole lot is fully glassed in and is rock solid.

Unfortunately, as I suspected might happen, the seal around the new section of tube and the old stainless is allowing a small amount of water through. Getting a perfect seal over stainless is improbable. It seeps through at 1.5 litres per 20 hours, and the leak is slowing down, maybe as the pinhole in the stern tube join clogs up. However, any improvement in the flow rate from any clogging isn't likely to be permanent.

The concreted area of the bilge has only had a flow coat put over the concrete so any leaks in this area, as noted by Ramona, aren't contained. The area will be dried out over the next few days, that flow coat will be ground back and the entire concrete area will be solidly glassed in. We can't improve the seal at the stern tube repair as any such work may exacerbate the problem due to the difficulty of getting a seal over stainless. But we are talking pinhole size and maybe 12" below water level so there is not much pressure behind the leak. As Ramona says, the entire concrete area will become the sealed in stern tube.

The principal risk is that the leak at the stern tube repair becomes worse and, if that happens, the water then finds a way through the glassed in concrete. The repair at the stern tube is well done and solid reducing the risk of the leak becoming worse. The pressure is not great so the risk of the leak coming through a weak point in the newly glassed in area is also reduced.

In the worst case and the leak does come through into the people bits of the boat a supply of Kneadit and/or Stay Afloat and a bilge pump will get me home. If that happens, out comes the concrete and in goes a new tube.

While a new stern tube is the ideal repair there are costs and risks in such a major restructure of the hull. The risk with the repair we are doing appears to be as low as reasonably practicable and is acceptable.

Who needs intellectual stimulation in retirement by working or studying, my boat gives me enough thinking activity thanks.

Good to hear you have that sorted. Having a bone dry bilge warms the cockles of me heart.

I had a problem with engine vibration when engaging gear some of you knew about, as per the above post when I thought it was the prop not opening. Turned out to be the gear cable was seized and she wasn't engaging gear properly, snatching and rocking the engine violently until it eventually fully engaged gear. I fitted a new gear cable and adjusted it late this afternoon.
She is now perfect (touch wood), the engine runs smoothly at all revs, gears engage smoothly in forward and reverse, the bilge is dry and there is no shaft or other vibrations.
A happy camper.

MorningBird said...
I had a problem with engine vibration when engaging gear some of you knew about, as per the above post when I thought it was the prop not opening. Turned out to be the gear cable was seized and she wasn't engaging gear properly, snatching and rocking the engine violently until it eventually fully engaged gear. I fitted a new gear cable and adjusted it late this afternoon.
She is now perfect (touch wood), the engine runs smoothly at all revs, gears engage smoothly in forward and reverse, the bilge is dry and there is no shaft or other vibrations.
A happy camper.

Well that is a relief. Not the most obvious thing to be looking for.

Probably a good idea to change your gearbox oil now after all that slipping and snatching. Could be particles of clutch material swishing around in the oil. Use a clean container to catch the oil so that you will be able to see any debris in the oil.

As that has happened to you it has given me a heads up on disconnecting my cables, checking their workability, lubricating them and readjusting them.

I gave them a good old squirt with Lanox including the gear box end before we left Lake Macquarie but that exhaust elbow is still dodgy and salt is building up around that area.

I have in mind to shift the engine control panel up next to the switch board plus move the other switches to a better location and fitting a small door there for better access to the dip stick and wet manifold. Once I get into that though it will be a complete re-wire.

I used to pull all my toys apart when I was kid. Old habits die hard.

No kneadit. We built a watertight bulkhead around the stern tube to prevent leaks from the stern tube getting into the bilge. A low risk solution. If every boat was as low risk as Morning Bird, the oceans would be much safer.