Extracting stern gland packing?

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This is an excellent description of the job.


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Fabulous - That is exactly the same as my gland - 2 bolts through a collar. Last time I adjusted it, I could remove the collar without any water coming in.

I did the job on land during the RYA Diesel Engine Course, so am familiar with the process... but real life on your own boat is always different.
 
I agree with Lemain- if it aint broke, don't fix it.
In addition to what he says, the time to change packing is when the gland plate, or nut depending on type, comes up tight to the aft part of the gland- i.e. when you run out of adjustment.
 
Lemain & North Up

Given that it is probably OK to do this in the water, I'll probably take the advice and leave it for now, but get the stuff and the tools sorted.

(Another reason for considering it was that she is on the hard and, assuming that all goes well with antifoul and keel etc., I wouldnt plan to have her out again until 2011).

Thanks to all for the help - nicely pre-empted

Richard
 
Agree with leave alone. It wil probably last over twenty years, depending on how much you use your engine, how much you grease it, and weaher you overtighten it when adjusting.
It will never fail quickly, and will gives you years of warning!
 
You should have a length of packing in your toolbox but you don't have to remove the old if you develop a weep and it is inconvenient while on a long voyage (thinking Malta to UK). Just put one coil in and replace the nut or plate. Five minute job if you have the right spanners and the threads are clean. With grease in there and without disturbing the existing packing no water will come through, anyway. Then do a proper job when you have the time to do a decent job. They fail slowly anyway and you can always put more grease in.
 
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You should have a length of packing in your toolbox

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I will have some by the end of next week /forums/images/graemlins/smile.gif
 
Another vote for the leave it alone argument. We have just replaced the shaft after 30 years on our boat, still the original packing, no leaks, kept well greased, but the shaft was beginning to wear.
 
Richard,

Based on my experience, the biggest worry is the flexible tube that joins the stern tube to the stuffing box. On my boat I don't think it had ever been changed since the original fit in 1988 so was very tired. When prising it off it just tore and fell apart. Sillette sonic (or another company in the Christchurch area, whose name I can't remember) area stock all different sizes in short lengths.

The worst the stuffing gland can do is drip - if the tube fails, that's another story.

Hope that helps
 
It doesn't seem long ago that the advice given on here was that graphite grease should never be used in stern glands. I can't remember the science involved but it was all to do with numbers, electrolosis, corrosion etc. You know the sort of thing.
 
Beware or be aware, grease is not always good, many stern glands operate perfectly well (as in the description by Mike Captain of Whitby) with out grease.

The reason why caution should be excercised is that grease is a poor conductor of heat and heat is the cause of many bearing and packing failures. Water is an excellent lubricant and coolant and a slight drip with the shaft running is a good thing for the shaft and packing. Stern tube cutless bearings can fail as a result of excessive use of grease in the stern gland, the grease travels back down the shaft and blocks the water channels in the bearing, again allowing heat to do the damage.
 
No, I said graphite-impregnated packing, not graphite grease. Graphite-impregnated packing is streets ahead of conventional and is the only sensible choice. The stern tube grease needs to be waterproof for continuous immersion and that is a special grade of grease. Bearing grease 'for trailers' will not necessarily meet the requirement for continuous immersion needed for stern tubes.
 
Agreed, especially the caution on the cutlass bearing.

I have an Infra Red thermometer (Maplins about £20) which is capable of reading very targeted points in the engine room from the doorway. I am able to check, just by opening the door, the alternator, battery box, block temperature, flow and return fresh water temperatures, exhaust temp, muffler temp and the stern gland, all without touching them. Every few hours when motoring I pop my head in and check the temps - takes less than 30 seconds.

If the stern gland is getting too hot it needs to be slackened, of course, and allow a little water to trickle or drip fast.
 
Found this reference HERE which talks about the different metals involved, bronze, ss, graphite etc and the fact that graphite is at the top of the galvanic scale so will eat everything. But there was an earlier one which warned about the dangers of your graphite impregnated packing despite the fact it was being enthusiastically pushed by chandlers etc. Think I'll stay safe and stick to Keenol and its equivalents which seem to have stood the test of time.
 
That's an old YBW thread and the comments are all about graphite GREASE. None of those comments relate to graphite-impregnated packing.

As I have now said three times, I am talking about graphite packing, NOT graphite grease. You need WATERPROOF grease, not graphite grease. I have never heard any negative comments about graphite-loaded packing and it is used by marine engineers all the time.
 
I've done a bit of googling on the graphite packing and most of the entries for graphite packing mentioned that they have a corrosion inhibitor.
 
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It doesn't seem long ago that the advice given on here was that graphite grease should never be used in stern glands. I can't remember the science involved but it was all to do with numbers, electrolosis, corrosion etc. You know the sort of thing.

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As I was told by Marine Eng'r - the type of grease depends on the type of packing used and shaft material. He advised that "Trailer axle" grease was universal and best to use as it had no problems with any packing or shaft material. It was also designed as water-proof.
 
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a woodscrew welded to a tee handle served me well for many years.


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Same tool I used for many years on water pumps down t'pit....

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Me too!
 
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