replacing old stuffing box shaft seals or not ?

BartW

BartW

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www.amptec.be
our boat has the old style stuffing box shaft seals,
in which your have to replace the greased rope every few seasons,
these seals have to drip salt water in the bilges for optimal greasing / cooling

while talking with my service guy in Porto Montenegro,
he mentioned that he replaced quite a few shaft seals with new modern seals from Tides Marine
they alway's place 2 spare rubbers over the shaft, when they install a new seal.
he is official dealer for TM
he could do the upgrade at a very low labour cost

AFAIK TM is a OK brand for shaft seals ?
is it worth doing this upgrade or would you stick with the old stuffed box seals ?
 
Stuffing boxes are one of those old fashioned things which are cheap, effective, and never let you down. Sales reps hate them because they stop them screwing you for money. Your choice.
 
TM here as well. Spares ready to go on shafts if needed. Dry bilges, no dripping and no annual maintenance. Highly recommended.
 
Think carefully about the water supply, preferably taken not from the bottom of acooling pipe but part way up, ensure each seal can be supplied by port and starb engines.
Put two spare seals on the shaft and prove the water supply from the engine to the TM seal annually should be a minimum of 4.5 litres per minute and if you run the boat up out of the water check the flow out of the sterntube.
 
Give Tides Marine International in the UK a call, really good people to deal with http://www.tidesmarine.co.uk/ they are a subsidiary of the USA manufacturer.

I use sureseal and we use loads both in leisure boats and small commercial 600hp ish.
 
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MapisM said:
Imho, no. If it ain't broke, don't fix it.
Click to expand...

+1, At least you can see if enough water is there, and who needs a dry bilge? drug smugglers maybe. A turn of the greasers every trip is no hardship. Many tales of failures with those "sealed" units, and you only get 2 chances of a fix at sea.

4.5 liters per minute?? to keep them happy??
 
I tend to agree with the "if it ain't broke don't fix it" principle, but if you do decide to change then I think the Tides seals are excellent. I've had them 10 years and 1,300 hours on the Princess, never touched them, and never a drop of water in the bilges.
 
Bart, I went trough this. I had also old style stuffing boxes but was fed up with dripping and consequent seawater in the bilge. I fitted Tides Seals instead and do not regret it. The works were carried out in Preveza. I was able to source the parts at fisheries supply in the US for less than half the cost than in Greece. A no brainer in my view, but true that I did only around 100 hours with them yet. Re cooling of the TS, should both supply pipes fail you are supposed being able to go home at slow displacement speed. Because there is enough water backpressure coming from the seaside?
 
Nick_H said:
I tend to agree with the "if it ain't broke don't fix it" principle, but if you do decide to change then I think the Tides seals are excellent. I've had them 10 years and 1,300 hours on the Princess, never touched them, and never a drop of water in the bilges.
Click to expand...

All very well if you do not use the boat! 130 a year?
 
I have Tides seals too - seem to work really well. But I like the stern glands, you know where you are with them. If it aint broke stick with it. save the money for something more important like good wine.
 
thank you all for opinions and advice,
for now, I will just leave it as it is, and I'm reassured that I can continue to use the "if it ain't broke don't fix it" principle.
I also learned that Tides is the OK brand whenever we want to do the upgrade.

Q: How about the P-bracket cuttleass bearings ?
do they need any preventive maintenance or regular replacement ?
we alway's check "play" on these at every lift out, but never renewed them
 
BartW said:
Q: How about the P-bracket cuttleass bearings ?
do they need any preventive maintenance or regular replacement ?
we alway's check "play" on these at every lift out, but never renewed them
Click to expand...
I suppose you're talking of what (AIUI) in EN are called shaft bushings, B?
If so, EN dictionary aside, no, I don't think it makes sense to replace them just for sake of prevention.

That said, on a boat with a setup like yours (IIRC - but correct me if I'm wrong: single arm bracket, no intermediate secondary bracket, thrust transmitted to the boat through the engine mounts), a correct shaft alignment and a good control of vibrations is very critical.
How is the check of play (or is it "backlash"? No big deal anyway, that's just EN wording again - who cares about it? :D) carried out, exactly?
It isn't trivial to understand how well the bushings are still doing their job, with a big and heavy shaft/prop.
Regardless, if (again, IIRC) you made more than a thousand hours with them since you bought BA, I'd be very impressed if they weren't worn out a bit...
Btw, if you would decide to replace them, you might wish to take the opportunity to have also the props controlled/balanced, if that's another thing you never did so far.
 
Cutless bearings in the P bracket

Depending on the setup of the engine ie is it perfectly aligned.

Whether the shaft is allowed to crud up with barnacles and hard growth before running again.

Silt or sand in the area of operation.

Whether rope or monofilament fishing line or plastic sheeting has wrapped itself around the shaft and been pulled in to the cutless bearing or has blocked the waterflow and an overheat has occurred.

A Cutless will normally last between 4 and 10 years.

Most boats have at least a Cutless in the P bracket and the stern tube they require a good water flow to cool and not overheat.

To be able to demonstrate a good maintenance and inspection routine to your insurance a shaft should be pulled to clean and inspect any type of stern seal about every 7 years including a traditional packed sternseal. If you are going to the expense and effort of pulling a shaft I would replace the cutless bearings anyway and personally I would fit a Tides marine Seal and enjoy a dry engine room.

I have no connection with Tides Marine other than a satisfied personal customer and we fit them to customers boats.
 
MapisM said:
I suppose you're talking of what (AIUI) in EN are called shaft bushings, B?
If so, EN dictionary aside, no, I don't think it makes sense to replace them just for sake of prevention.

That said, on a boat with a setup like yours (IIRC - but correct me if I'm wrong: single arm bracket, no intermediate secondary bracket, thrust transmitted to the boat through the engine mounts), a correct shaft alignment and a good control of vibrations is very critical.
How is the check of play (or is it "backlash"? No big deal anyway, that's just EN wording again - who cares about it? :D) carried out, exactly?
It isn't trivial to understand how well the bushings are still doing their job, with a big and heavy shaft/prop.
Regardless, if (again, IIRC) you made more than a thousand hours with them since you bought BA, I'd be very impressed if they weren't worn out a bit...
Btw, if you would decide to replace them, you might wish to take the opportunity to have also the props controlled/balanced, if that's another thing you never did so far.
Click to expand...

hi P, yes its the shaft bushings,
I alway's see these in my spare parts catalog from Ceresoli in Fiumicino ;-)
that's why I was wondering when I would need them

indeed so far we have never put new, and I guess the previos owner didn't change them the year he sold the boat,
so they have far over 1000hrs.

you're right about my setup, and I agree that good controll of vibration is critical,
and can confirm that since the liftout of the engines, the shafts re-alignment is equal or better than before
(its my subjective feeling of boat vibration, no other objective proove)

in the past I saw a surveyer lift the prop, to check if there is "play" on the bushing,
In montengro the yard in Zelenica they make a lever arm with a wooden beam on wooden blocks to lift the prop, for checking play on the bushing.
and last year I have seen it myself that there was not even a little 'play ' (between shaft and bushing)

in a few weeks the boat will be lift out, if you have other / better tests, pls let me know

the props have been refurbished in 2013, when the boat was lift out for the stab installation,
remember; for repairing little cavitation holes,
repair was done by a pro prop specialist in holland, and I assume they know what they were doing,
 
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