Deep sea seal versus traditional packing box and greaser

I have a 4 foot propshaft with some groves in it from the old stuffing gland. Shaft is now used to hold a small fence up in the garden. New shaft and volvo seal in the boat means I have to use the vacumn cleaner to dust the bilges now :D would I go back to a bit of rubber hose with brass nuts, some stuffing and loads of grease? are you kidding.

Pete
 
One of the reasons that the industry might have moved to "dry" methods of sealing is the move to shallow bilges. I suspect the Twister like our boat has deep bilges and a good sump where the drips from a stuffing box gather quite harmlessly until pumped out. I personally wouldn't bother changing ours...
 
My traditional stuffing box has been in place at least since 1970 and quite possibly since about 1950 because the bit of wood it is bolted too is probably original. I think the previous owner replaced the packing (traditional not PTFE), so that would have to be at least 10 years ago. I have refilled the greaser once but I quite often forget to give it a turn. I suppose we get some water through it, but I've never actually seen a drip fall, and it's never enough to pump out. I guess the Aquadrive helps because there is no vibration in the shaft.

Can't think of a reason to change it.
 
Rubber hose? That will be a flexible inboard gland, not a stuffing box. If Moody's put brass nuts in there, no wonder you wanted to change. icon smiley thing but I'm blowed if I know how to do that now since this forum became modern. icon smiley thing!
 
... and another thing! If you need to replace a rubber seal you will have to disconnect the propshaft coupling and remove the coupling, which can be difficult [see past posts on this forum] whereas you can replace the stuffing box packing without disconnecting the shaft. You can even renew it whilst afloat.
 
Badger said:
I have a tradional packing box and stern gland greaser on my Twister 28.
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I would put up with it. I suspect it would be a horrible job to replace on the Twister.
On the other hand if you have to take the engine out anyway or are updating your propshaft then the PSS is a good option. I thing Nigel Calder wrote about the topic in a recent Yachting Monthly...
 
I like the look of PSS Shaft Seal

I think this looks like a good solution. I am having her re-engined so want to get a low maintenance safe and reliable solution in place and this looks like a good option. The big question now is ..... do I fit an Aquadrive whilst I'm at it but that may need a seperate post. Thanks for all inputs.
 
Badger said:
I think this looks like a good solution. I am having her re-engined so want to get a low maintenance safe and reliable solution in place and this looks like a good option. The big question now is ..... do I fit an Aquadrive whilst I'm at it but that may need a seperate post. Thanks for all inputs.
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If you are doing a major re-engine job then Volvo seal is the way to go if you can. Half the price of others and IMHO far superior for the reasons stated in earlier posts.

Aquadrive is very expensive, needs a lot of engineering to install. Good results on the smoothness front can be obtained from choosing a smooth multi cylinder engine and a flexible coupling such as a Bullflex or a Centra.
 
Badger said:
I think this looks like a good solution. I am having her re-engined so want to get a low maintenance safe and reliable solution in place and this looks like a good option. The big question now is ..... do I fit an Aquadrive whilst I'm at it but that may need a seperate post. Thanks for all inputs.
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From an engineering point of view, the answer to the aquadrive is a resounding yes. To put the prop thrust through the engine bearers is an abortion even though they are now designed to take it. The shaft alignment is changing all the time, the prop and shaft are moving backwards and forward and the result is viobration and wear. But is the aquadrive necessary or a luxury? The answer has to be luxury.

As the user of Volvo shaft seals I wouldnt suggest going that way. They do work but with a cost of £85 and a life of 5 years or so they are way more expensive than the seals that have a brass tube fitted with 3 standard lip seals and an oil reservoir. the lip seals can be bought from any engineers sundryman.

Once did a longish trip on a container ship and was fascinated to find that their shaft seals were also lip seals. big ones mind you!
 
lip seal conditions which bring about failure!

Good advice from many.Main thing touched upon is that engines move about on rubber mounts..Having fouled a rope on a previous vessel, the gap between the p Bracket and the prop was forced back about 3" by the coil of rope and the engine torn from it's mountings.There was no ingress of water as the traditional stuffing box was in use.
A lip seal would have turned this into a sinking.

Another time off Bardsey Island Wales, the boat fell off a wave so hard that the engine moved off its mounts sideways, still attached by two mounts.Later it was possible to move the engine back.
Due to the stuffing box remaining in place no water entered the vessel.

LESSON LEARNED:
A boat should be engineered differently to a washing machine, to cope with incidents which occur sometimes in the middle of the night!
If you have one of these lip seals,it may help to fit a rope cutter of proven performance.
good sailing n boating to all!
 
paulclan said:
A lip seal would have turned this into a sinking.

QUOTE]

Could you explain why this might happen? Lip seals work in exactly the same way as a stuffing box except the "seal" around the shaft is made by the lip seals rather than compressed packing. Therefore if the shaft moved back it would still seal but on a different part of the shaft.

I think you are referring to what might happen with a face seal - although if the shaft moved back it would compress the bellows and actually make the seal "better" until something mechanically failed.
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jason -and the arguenauts said:
As the user of Volvo shaft seals I wouldnt suggest going that way. They do work but with a cost of £85 and a life of 5 years or so they are way more expensive than the seals that have a brass tube fitted with 3 standard lip seals and an oil reservoir. the lip seals can be bought from any engineers sundryman.

!
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I could not agree more with your recommendation, particularly as I have been involved in marketing that type of seal in the past. However, as far as I know nobody offers them today, at least in the UK.

Why?- two reasons. Firstly saildrives now account for at least 50% of new builds in the yacht market and the majority of the conventional shafts use the Volvo seal. The demise of boat building in the UK means there is little OE market. Secondly, they were more expensive than any other design if done properly and the market simply would not pay the price in any volume.

As to wear, my Volvo is now in its 12th season with no signs of wear. The Sure Seal (which also uses lip seals, but is nearly twice the price) only guarantees 2000 hours or 2 years. Admittedly the seals are cheaper to replace.

Hardly surprising that the Volvo at £85-100 in yacht sizes is the market leader in both OE and replacement markets.
 
volvo gland burping

I do it, burping the volvo gland that is, but is it necessary, boat is on a drying mooring and I have to empty the cockpit locker and climb in to burp it on the Westerly Konsort. In fact I am designing a pair of long pincers to access the gland from above the engine,
A big drawback to the Volvo gland if your boat dries out.
 
Agree about the potential for catastrophic failure with Deep Sea and other lip seals. Personally I've found the Halyard oil seal very trouble-free, but on my last boat I had a stuffing box and had no problems with this either.
 
paulclan said:
Good advice from many.Main thing touched upon is that engines move about on rubber mounts..Having fouled a rope on a previous vessel, the gap between the p Bracket and the prop was forced back about 3" by the coil of rope and the engine torn from it's mountings.There was no ingress of water as the traditional stuffing box was in use.
A lip seal would have turned this into a sinking.
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Got to smile at that one. A pal with a Sadler 29 and a lip seal type fitting from new wrapped the mooring chain at Porlock Weir round jhis prop to such good effect that he broke the gearbox casing. Sure he had oil all over the bilges but no water came in.

There is absolutely no reason why either a stuffing box or a lip seal typ[e seal would be any differnt in the situation you describe.
 
dulcibella said:
Agree about the potential for catastrophic failure with Deep Sea and other lip seals. Personally I've found the Halyard oil seal very trouble-free, but on my last boat I had a stuffing box and had no problems with this either.
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Not wishing to be too pedantic, but as it is critical to the discussion over designs.

A Deep Sea seal and a PSS are FACE seals.

Volvo, Tides (sure seal) and Vetus are lip seals around the shaft in the same way as a stuffing box. The Halyard seal using oil as a lubricant and lip seals to keep the oil in and water out.
 
Worried now, there are posts suggesting that peoples' packing glands don't leak much. The old boy that taught me the basics 20 years or so ago told me the worse thing was to over-tighten them, you want to see a drip every couple of minutes with engine at rest I was told. I have dutifully set them that way ever since. I am also sure I read the same advice in the instructions of one I installed not so long ago. Wrong?
 
In 40 years of sailing I have heard of probably 12 sinkings caused be modern shaft seals. But non by by traditional glands . If Insurance picked up on those odds premiums would go up!
 
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