stuffing box blues

[ex-Gladys]

Amber has a high speed PSS fitted, albeit with the water tube cut off 9" high and plugged. the idea is to make sure you get all the air out....

<hr width=100% size=1>Larry Botheras

Anderson 26 "Amber"

 

[Robin]

We fitted the same one, after asking advice from PSS by e-mail, and fitted the water inlet with a tube which is taken well above the waterline. This then avoids any need to 'burp' or bleed the air from the seal after relaunching. It also provides a small 'head' of water pressure on the seal. So far it is all working fine.

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[roger]

There are two possibilities
a. fit a small tap on the little pipe below water level so you can flood the seal when the boat goes in the water. It may be more convenient than pulling the rubber concertina back.
b. Do as they suggest. This will make the whole process automatic. In addtion if your seal can run dry in some odd circumstances (? heeling a great deal while running engine) this will protect the seal. You should not need more than a dribble into the seal so you should be able to make sure enough water is left for the exhaust cooling.

<hr width=100% size=1>Roger

 

[Sinbad1]

Back to basics.

First you have to check that you have the correct size packing. They come in both metric and imperial sizes and if you have the incorrect one they will leak as you have described.

If you repack with the correct size and it leaks then you could try the next size up as it will be a worn shaft and this solution will hold father neptune at bay for a while longer until you can either move the shaft in/out or remetal......

...most likely cause of vibration (once you have checked clearances where shaft attaches to gearbox) is an out of balance prop. If you have collected some hefty rope or similar in the past it may even be a slightly bent shaft....all good fun and not difficult to fix if the right facilities are nearby.

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[StephenW]

From what you describe it sounds to be that misalignment of the engine (and shaft) is allowing water to penetrate into the boat through the stuffing gland seal.

We had a similar situation and it was cured by correct engine alignment. Misalignment will lead to rapid wear of the stuffing material and leaks. We have a flexible Vetus coupling and vetus flexible (rubber) mountings here's how we did it, it may be easiest when dried out.

The shaft on our boat goes into the flexible coupling which is then bolted onto the gearbox flange plate. If you loosen the flange plate bolts a little, to allow a small gap (2-3 mm) you can put your fingers close into this small gap and rotate the shaft by hand and "feel" with your fingers around the gap whether the gap is changing as the shaft is rotated. If it does then you are misaligned. Tighten up the bolts a bit so the gap is now feeler guage-able and check at which pint the rotation closes the gap. Use this to judge which way the engine needs to be moved.

It's easier to get the alignment sorted if the mounts near to the shaft are adjusted to approx the right height first. Again, if you loosen the nuts on the gearvbox plate and slowly withdraw the shaft the bolts (attached to the back of the flexible coupling assemby) should slide out cleanly with the shaft -if there is misalignment(too low/high/sideways) it will be evident. Just raise or lower the feet (top nut and lock nut beneath on ours enable adjustment). End of engine farthest from coupling can also be roughly aligned using this method prior to feeler guage treatment.

When we did ours the wear and need to adjust became negligable - maybe every 20 hours or more.

Good luck and I feel this is almost certainly the source of your problem.
ps make sure you allow 1-2 drops per minute from packing or the shaft will overheat.

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