Leaking stearn tube

[steveeasy]

As the title says I’ve a leaking stearn tube. Quite common apparantly. Not the tube but a breakdown in sealant between stearn tube and hull.

Apparantly people fit a GRP one so it bonds better. The wall thickness is greater with a GRP tube so to allow room for The shaft I have to bore the hole from 38mm to 44mm.

So does anyone know a firm or person who is based in or around Oban that could do the boring bit. Nearest chap I can find is on the Hamble and won’t get much change from £2000. Of course I could fit a replacement bronze tube but bit worried it will leak again. Yes it’s a CO 32.

Steveeasy

 

[doug748]

There was a bloke on the old Contessa site who explained how he did this DIY. Though as I recall there was a fair bit of engineering in his method.
I think a good job with a bronze tube might last another 50 years. Perhaps George Instead might advise or a plea on the Facebook page?
.

 

[steveeasy]

I wonder if a bronze one might be a lot easier. Nearly every oldish GRP boat has a bronze tube. Surely it’s just a matter of getting the flange on the outside bedded properly with the correct compound. I could then re use the current stuffing box which is great.

Inside id be tempted to use something like OBD 1, Flexible and watertight after bonding with expoxy.

Steveeasy

 

[NormanS]

As the title says I’ve a leaking stearn tube. Quite common apparantly. Not the tube but a breakdown in sealant between stearn tube and hull.

Apparantly people fit a GRP one so it bonds better. The wall thickness is greater with a GRP tube so to allow room for The shaft I have to bore the hole from 38mm to 44mm.

So does anyone know a firm or person who is based in or around Oban that could do the boring bit. Nearest chap I can find is on the Hamble and won’t get much change from £2000. Of course I could fit a replacement bronze tube but bit worried it will leak again. Yes it’s a CO 32.

Steveeasy

Many years ago when I was building a wooden yacht from scratch, I had to bore the stern post, deadwood etc. I drilled through with a long 7/8" pilot drill. I made a couple of very basic plummer blocks, and using a string, fixed them securely and accurately, one inside and one outside the boat. I obtained a length of 3/4" bright steel bar, drilled it at mid length to take a piece of tool steel, which was locked in place with a grub screw. The bar was threaded through the plummer blocks, and a large electric drill arranged to rotate it. The tool could then be adjusted to take a modest cut, as the rotating bar was slowly advanced through the stern post. It worked perfectly, and the bronze stern tube did its job. Possibly you could do similar. I may even still have the equipment, if you would like to have it.

 

[Poignard]

I wonder if a bronze one might be a lot easier. Nearly every oldish GRP boat has a bronze tube. Surely it’s just a matter of getting the flange on the outside bedded properly with the correct compound. I could then re use the current stuffing box which is great.

Inside id be tempted to use something like OBD 1, Flexible and watertight after bonding with expoxy.

Steveeasy

That's what I did on my Twister, except for the epoxy, and I'm not sure what you mean by 'inside'

I can't recall what bedding compound I applied to the flange was but it would probably have been something I got from Arthur's Chandlery in Gosport.

It's also important to seal the threads with some suitable thread sealant. I probably used Loctite 572.

I don't see why you need to use any epoxy, or where you would use it. In fact I wouldn't.

Anyway, I see I did the job in 2002 and it wasn't leaking when I sold the boat last month so the technique seems to have worked.

 

[steveeasy]

Many years ago when I was building a wooden yacht from scratch, I had to bore the stern post, deadwood etc. I drilled through with a long 7/8" pilot drill. I made a couple of very basic plummer blocks, and using a string, fixed them securely and accurately, one inside and one outside the boat. I obtained a length of 3/4" bright steel bar, drilled it at mid length to take a piece of tool steel, which was locked in place with a grub screw. The bar was threaded through the plummer blocks, and a large electric drill arranged to rotate it. The tool could then be adjusted to take a modest cut, as the rotating bar was slowly advanced through the stern post. It worked perfectly, and the bronze stern tube did its job. Possibly you could do similar. I may even still have the equipment, if you would like to have it.

Thats a really kind offer. Not sure I fully understand how it worked. I’m sure I will though after a few more posts.
Thank you!
Stephen

 

[steveeasy]

That's what I did on my Twister, except for the epoxy, and I'm not sure what you mean by 'inside'

I can't recall what bedding compound I applied to the flange was but it would probably have been something I got from Arthur's Chandlery in Gosport.

It's also important to seal the threads with some suitable thread sealant. I probably used Loctite 572.

I don't see why you need to use any epoxy, or where you would use it. In fact I wouldn't.

Anyway, I see I did the job in 2002 and it wasn't leaking when I sold the boat last month so the technique seems to have worked.

Well the stearn tube passes through the Skeg which is a void about 18 inches long and a ft deep. When the tube was fitted they filled the void with foam. It’s then glassed over.

I took the engine out and cut open the void, dug out all the foam. So when I fit a new tube the void needs filling, to secure the tube fully and create a further barrier to stop water ingress.

The tube on a contessa is primitive. Just tube with outer plate. No threaded bits, just rubber hose on inside that the packing thingy hangs on. Bush bash bosh type of design.

When the tube is inside they glass over both outer surfaces to bond it in.

Steveeasy

 

[WoodyP]

For me it was a simple matter to apply some sealant and screw it down tight..

 

[Tranona]

For me it was a simple matter to apply some sealant and screw it down tight..

Read the description - no threaded parts, just a tube pushed in from the aft end against a sealant then glassed in at the forward end. Wonderful piece of crude boatbuilding!

 

[Sandy]

As the title says I’ve a leaking stearn tube. Quite common apparantly. Not the tube but a breakdown in sealant between stearn tube and hull.

Apparantly people fit a GRP one so it bonds better. The wall thickness is greater with a GRP tube so to allow room for The shaft I have to bore the hole from 38mm to 44mm.

So does anyone know a firm or person who is based in or around Oban that could do the boring bit. Nearest chap I can find is on the Hamble and won’t get much change from £2000. Of course I could fit a replacement bronze tube but bit worried it will leak again. Yes it’s a CO 32.

Steveeasy

If you have not already done so have a look at the Refit and Sail YouTube channel, George has done the same job there.

A lovely chat who was delightfully surprised when I shouted over to him to say how I was a keen follower of the channel last time I was sailing into Cowes.