Stuffing box type seal on my rudder

[pcatterall]

Lots of water coming in the other day. Traced it to the bearing/sealant the top of the rudder. After much faffing around with torch and mirror I saw it was something which looked like stuffing box with two bolts pinching up two plates. The nuts on top were finger tight and with more resource to light and mirrors I was able to tighten them, still a slight leak so put a bit more torque on them. Now a very slight drop. There is no appreciable increase in stiffness at the wheel.
I wonder if this is a common arrangement on circa 1974 boats? And is it real a compression type seal? Can it be overtightened? I can't see that heat would be an issue unlike on a prop shaft.
Not a big problem now but just interested.

 

[sailorman]

I have the same set-up on my boat, just nip it up as for a prop shaft, it is after all a low RPM prop shaft & far superior to the noo fangled Jeffa that need replacing every few yrs :encouragement:

 

[earlybird]

My 1970 She31 had a rudder shaft seal packed with square yarn packing, compressed by a big nut, ie very similar to a prop shaft seal

 

[rob2]

I believe it's not uncommon from those days (and some current production designs) for the rudder tube to barely come as high as the waterline, so the water slops in if no seal is fitted. I've never really figured out why every tube doesn't come right up to the rudderhead, giving it far more support and rigidity - what advantage could there be in missing out on the extra strength? Quite apart from the strength of the tube itself, it moves the upper bearing further above the bottom bearing, so it carries less stress. I've always felt that a full length tube with buttress webs to stiffen it is the way to go.

But for those with seals like yours I doubt there is any reason not to tighten it right up to the point where the friction becomes noticeable. I would expect to find PTFE packing in it as it is only lubricated with the water slopping around in the tube and there is no heat build up which is what PTFE doesn't like in a propshaft application.

Rob.

 

[Rivers & creeks]

Mine is the same as the OP but now also has a greasing tube.

 

[macd]

Ultimately it may need re-packing, but as sailorman suggests, it doesn't have to deal with many rpm (1?) so the wear rate is glacially slow. Equally, it doesn't need cooling, so unlike a prop shaft stuffing box, can safely be nipped up to prevent any drips. At least, that's my approach with ours.

 

[sailorman]

I believe it's not uncommon from those days (and some current production designs) for the rudder tube to barely come as high as the waterline, so the water slops in if no seal is fitted. I've never really figured out why every tube doesn't come right up to the rudderhead, giving it far more support and rigidity - what advantage could there be in missing out on the extra strength? Quite apart from the strength of the tube itself, it moves the upper bearing further above the bottom bearing, so it carries less stress. I've always felt that a full length tube with buttress webs to stiffen it is the way to go.

But for those with seals like yours I doubt there is any reason not to tighten it right up to the point where the friction becomes noticeable. I would expect to find PTFE packing in it as it is only lubricated with the water slopping around in the tube and there is no heat build up which is what PTFE doesn't like in a propshaft application.

Rob.

My stock come up through the aft deck ready to accept the emergency tiller, so has a bearing @ deck level

 

[Tranona]

I believe it's not uncommon from those days (and some current production designs) for the rudder tube to barely come as high as the waterline, so the water slops in if no seal is fitted. I've never really figured out why every tube doesn't come right up to the rudderhead, giving it far more support and rigidity - what advantage could there be in missing out on the extra strength? Quite apart from the strength of the tube itself, it moves the upper bearing further above the bottom bearing, so it carries less stress. I've always felt that a full length tube with buttress webs to stiffen it is the way to go.

But for those with seals like yours I doubt there is any reason not to tighten it right up to the point where the friction becomes noticeable. I would expect to find PTFE packing in it as it is only lubricated with the water slopping around in the tube and there is no heat build up which is what PTFE doesn't like in a propshaft application.

Rob.

Simple reason. On the oP's boat the rudder stock and steering gear is under a bunk in the aft cabin, so below the waterline and therefor needs a seal. Stuffing boxes were common, but for similar applications now a lip seal is more common, but not adjustable like a stuffing box.

On some boats it is possible to bring the stock and tube up to deck level and a seal is not needed.

 

[sailorman]

Simple reason. On the oP's boat the rudder stock and steering gear is under a bunk in the aft cabin, so below the waterline and therefor needs a seal. Stuffing boxes were common, but for similar applications now a lip seal is more common, but not adjustable like a stuffing box.

On some boats it is possible to bring the stock and tube up to deck level and a seal is not needed.

Didnt Bavaria use a GRP "road cone" to support the stock

 

[macd]

I've never really figured out why every tube doesn't come right up to the rudderhead, giving it far more support and rigidity - what advantage could there be in missing out on the extra strength? Quite apart from the strength of the tube itself, it moves the upper bearing further above the bottom bearing, so it carries less stress. I've always felt that a full length tube with buttress webs to stiffen it is the way to go.

In structural terms, you have a point. But think centre cockpit. Would you want a rudder tube through your pillow?

(Hasten to add that I'd be worried, too, if there weren't a substantial full skeg.)

 

[sailorman]

In structural terms, you have a point. But think centre cockpit. Would you want a rudder tube through your pillow?

(Hasten to add that I'd be worried, too, if there weren't a substantial full skeg.)

I have a large spade rudder, so far so good :encouragement: