Dry bilge

[mick]

I had a new engine fitted to my Sadler 26 for the start of this season, and the engineer repacked the stern gland. The engine has now done 120 hours and I rarely have to pump the bilge out ( only half a dozen times in 3 months). The engineer says the packing will gradually wear and let more water in. The engine runs beautifullyand the boat fair bowls along. Yesterday I had to motor for 8 hours straight. There is no hint of a problem and still I worry, because that's the way I am. Comments, please (about the bilge, not the neurosis).

 

[thomashoebus]

As you say there is no problem.

There are to my knowledge 4 main different types of stern glands some drip and others are not leaking at all. The ones who are drip free should be replaced every 5 years and are the ones who could be potentially the most dangerous when starting to leak suddenly.

I don't think that you have a drip free one. You just should regulary monitor the rate of dripping and act accordingly some glands need greasing or thightening. In other glands you should replace the rope,...

You could ask the engineer who did the repacking what type you have now and how you have to do the maintenance.

greetings

Thomas

 

[Birdseye]

to my mind, ever having to pump the bilge is dodgy. the general idea is that water stays outside the boat not in it. but I suppose if you are using the old fashioned grease and packing type seal ...................................

 

[Greenwichman]

Not wishing to add to your worries, but in 40 years' sailing in all kinds of boats I have always managed to keep a dry bilge. If you have a leaking stern gland you should have it looked at. One possible cause is a misaligned shaft.

 

[Pye_End]

You should be looking at a drip every 30s or so when under way. Much more then you should tighten the grease (is it a remote greaser or it this done on the stern tube?) until it reduces. If the stern gland becomes hot you have gone too far.

If you think that you are using way too much grease, chances are it is time to replace the packing again.

Failing that change to a non greasing type - much better in my opinion, but others will say (and rightly so) that there is much less chance of a chatastophic failure with a grease type.

 

[paul_williams]

I do this for a living, so here goes. some drip, some don't. if its not getting hot, don't worry about it. if it is, loosen the gland nut a little, a little drip every few minutes is fine whilst the shaft is turning, your not going to sink. the drip should stop when the shaft isn't turning. and remember, you can always stop it leaking by pumping in more grease, and it can be repacked if required. unlike them horrible mechanical type seals that either work, or alarmingly don't.

 

[Ships_Cat]

unlike them horrible mechanical type seals that either work, or alarmingly don't

An alarmingly alarmist generalisation which may give some the wrong impression, especially as you claim some experience.

There are mechanical propeller shaft seal units which in the case of the seal failing (and if a lip seal type that will only be a minor event in any case) then the water flow is not a problem at all. In fact, with our own it is possible to run the boat without the actual seal in it (I could not think of any event which would require that, but I have tried it to see) and the inflow of water of water is minimal - that because of the close clearances and the greasing.

Even disregarding that, all the tried ones have proved themselves as being very reliable in service - probably more so than packed glands which are never now installed on high quality boats.

John

 

[cliffordpope]

Speaking from years of experience with traditional stern tubes, they all drip a bit. Better to drip then be too tight. In a wooden boat what's the odd drip anyway? If you are worried about it dripping unattended when you leave the boat between holidays, give it a pump of grease after shutting down. You could even tighten the packing, and then loosen it a bit next trip.
Put a can under it and tip it out daily when you do your routine check before starting off?

 

[HONESTJ0HN]

My stern gland leaks, and I am fed up baling out water from under the engine ! So I am going to have to re-pack it. Can I do this without taking the boat out ? When I do the repacking, should I wrap the material in a spiral, so that the spin of the shaft forces water out? Or should I cut and fit a series of offset lengths.