shaft seals, lip seals,..oh my

[Vasco]

I've had a Volvo seal on my B393 for eight seasons now. I am not a fan of dripless seals but the boat came with the Volvo seal. I think the instructions are to change the seal every 500 hours but that seems crazy. Mine still works flawlessly. I hope I haven't jinxed it.

I much prefer the traditional stuffing box. I can change the packing in my CS36 in about half an hour, in the water. I just wrap a bit of rubber from a bicylce inner tube around the stern tube and no water comes in while I change the packing.

[Pete7]

Agreed, volvo seal was the best thing we have fitted to the boat. Now I use the dust pan to clean the bilges. Cheap too

Pete

[sailorboy1]

Originally Posted by funjohnson

I installed a lasdrop a year ago.... Cannot get the thing to stop spraying water! I've aligned the engine, but that was square. I guess I could have a bent shaft, but I get no vibration. It was ok while I was in fresh water, now that I'm in salt, the spray and constant pumping is driving me crazy. Last night, the bulge pumped 4 times in 24 hours.

Sounds like you have "original", the one with the bellows that looks like a PSS?

Are you sure the seal is leaking and not the bellows? I at first though my leak was the seal and adjusted the tension by moving the seal down. All that did was compress the bellows more, which made the leak bigger which helped identify the problem and send me into a panic!

Wrapping the bellows with rescue tape worked for 3 months, but the experience of what could have happened if that leak from the seam in the rubber bellows had torn open just has me freaked out about the whole thing!

[Matt Johnson]

Originally Posted by Don Lucas

Sounds like you have "original", the one with the bellows that looks like a PSS?

Are you sure the seal is leaking and not the bellows? I at first though my leak was the seal and adjusted the tension by moving the seal down. All that did was compress the bellows more, which made the leak bigger which helped identify the problem and send me into a panic!

Wrapping the bellows with rescue tape worked for 3 months, but the experience of what could have happened if that leak from the seam in the rubber bellows had torn open just has me freaked out about the whole thing!

Oh yeah it's the friction point between the two graphite pieces. You can see water flick out of it when its spinning. I just had my head in the engine room adjusting it again to see it I can find a way to stop the leak.

I'll put back in the conventional stuffing box when I pull the boat out for its next bottom job (two years from now. For now, I just have to find a point where it leaks the least. I just worry about the engine bay rusting with all that salt water.

This was the worst upgrade I made on the boat! I had dripless packing in the old box that worked great, but I wanted to replace the stuffing box hose and findout the stern tube and stuffing box were different sizes. Instead of buying a new conventional box, I thought the Lasdrop would be a good option... Nope.

[delmarrey]

Originally Posted by Don Lucas

Wrapping the bellows with rescue tape worked for 3 months, but the experience of what could have happened if that leak from the seam in the rubber bellows had torn open just has me freaked out about the whole thing!

So, why haven't you changed it out in the past 3 months?

[sailorboy1]

Originally Posted by delmarrey

So, why haven't you changed it out in the past 3 months?

because I haul out each year and the the tape worked good enough that I had at least the same level of confinence in the tape that I had for the bellows (and I wrapped that puppy), in the end since the tape did the job I decided to same the $1000 and lost sailing time for a mid season haul out

[delmarrey]

Originally Posted by Don Lucas

because I haul out each year and the the tape worked good enough that I had at least the same level of confinence in the tape that I had for the bellows (and I wrapped that puppy), in the end since the tape did the job I decided to same the $1000 and lost sailing time for a mid season haul out

I changed mine while in the water.

Ya just soap up the shaft, slide it back, remove the coupler, have the new bellows ready, keep rags handy, slide one off and the other on, tighten it all down, done. Clean up a little water.

[Hudson Force]

Originally Posted by delmarrey

I changed mine while in the water.

Ya just soap up the shaft, slide it back, remove the coupler, have the new bellows ready, keep rags handy, slide one off and the other on, tighten it all down, done. Clean up a little water.

I guess this would be an opportunity with a short shaft length inside and a span with a strut outside. I've got about five feet of shaft inside and I must remove my prop before I can move the shaft aft by more than one foot in order to clear the rudder. Even if I could shove my long shaft back with the prop on, I can't imagine hanging all that back with the bitter end of my shaft hanging on the cutlass bearing. I can imagine how this could work for some.

[delmarrey]

One only needs to push the shaft back far enough to get the old (flexible) bellows off. 5" at the most on mine. My concern would be getting the coupler off on some boats, considering how some take care of their equipment.

Actually, on mine I only have to slide the shaft out of the coupler and remove the Pythondrive bearing. The 5" was before I installed the Pythondrive.

[perchance]

The problem with rotary face seals is any amount of dirt or grit will cause them to leak.
Mechanical seals with graphite and ceramic components will not even tolerate the oil from your fingers.

[sailorboy1]

well I'm currently thinking to just go the packing route, with modern packing the small amount of leakage is minor compared to reliability

but I still have time to change my mind again

[Sailmonkey]

Originally Posted by Don Lucas

well I'm currently thinking to just go the packing route, with modern packing the small amount of leakage is minor compared to reliability

but I still have time to change my mind again

I would still have a packing gland if I could get to it without emptying the cockpit lockers, lubricating my torso, and having extrication lines tied to my ankles.

[sailorboy1]

Originally Posted by Sailmonkey

I would still have a packing gland if I could get to it without emptying the cockpit lockers, lubricating my torso, and having extrication lines tied to my ankles.

Wouldn't that be a argument for having packing instead of something that if it had a problem you are kind of screwed?

I have excellent access to my seal area, which why I was able to use the rescue tape to stop the bellows leak. Otherwise I proably would have a mid season haulout to deal with it.

[Sailmonkey]

Originally Posted by Don Lucas

Wouldn't that be a argument for having packing instead of something that if it had a problem you are kind of screwed?

I still carry the packing gland on the boat (with three new turns in it) and if needed I can get to the shaft/packing area and change out the whole mess in less than an hour if need be. But crawling into the bowels of hell for regular maintenance was too much. Besides, if the whole PSS craters on me the amount of the water that comes through the shaft log isn't the end of the world, our cutlass is in the deadwood so there's not all that much room for the torrent to flow.

[delmarrey]

Originally Posted by Sailmonkey

Besides, if the whole PSS craters on me the amount of the water that comes through the shaft log isn't the end of the world, our cutlass is in the deadwood so there's not all that much room for the torrent to flow.

Ditto!

I don't know what the big deal is with the PSS. If one does regular maintenance like they should then they are dry and maintenance-less. And if the bellows ever did leak due to lack of self initiative, then one could just shove a rag in around the shaft and that would get one home just fine.

A rag impregnated with wax is about the same as packing rope. If one looks at how stuffing boxes (packing glands) work. It's basically a piece of fiber rope crushed square which has been saturated in a wax/silicone mix, teflon or graphite.

When the shaft turns and is tight enough to stop the leak it gets hot melting the wax which creates a lubricant. When the shaft stops and cools it gets hard again and seals the shaft to the gland. When it starts back up it breaks the wax and starts heating up again.

The secret to keeping the boat dry is the constant adjustment to the gland to compensate for wear and allowing a drip as a coolant. If they get too hot they loose the waxy substance and will always leak. In turn needing another wrap of packing, which should be changed out completely, if burned. A stuffing box should be a little warm if adjusted right, but not hot.

With the PSS one does not have to go through all this BS, if installed properly.

And how would one get dirt in a shaft seal? Go 4 wheeling with the boat?