My stuffing box is leaking like crazy and has not been repacked in the 10 years I've owned the boat. I did add a layer of stuffing several years ago and it worked great. Now I need to make a decision whether to remove the old stuffing and replace it or go with a dripless. I've heard good pros and cons of both, but thought I would pose the question here... Traditional stuffing or dripless? Thanks!
Traditional Stuffing or Dripless?
- Thread starter gfroch
- Start date
I replaced the 'plastic' stuffing box with a LasDrop Gen II dripless shaft seal. It has been leak and problem free for years. The old stuffing boxes, preferably bronze, have been around forever and can be repacked easy enough, but they will always leak a little bit. The 'dripless' seals are just that. I've read where they can have catastrophic failures but I've never known anyone that has experienced that.
I just finished doing some research on both. The dripless are expensive to buy, expensive to rebuild and can be catastrophic when they fail. The ones without burp tubes need to be manually burped. @Tally Ho reported that he finds air in his Volvo seal pretty much every time he goes for a sail. That's enough to tell me that there's potential for a short shaft life if I forget to burp it, which I will. My last boat was off the dock in 10 minutes and I'd like to keep it that way.
Because of these factors I ended up going with Gore GFO packing. It only drips a few times per minute when the engine running and none at all when the engine is off. Nautiqueparts.com has the cheapest prices and reasonable shipping. Here's an excellent article regarding this subject
Because of these factors I ended up going with Gore GFO packing. It only drips a few times per minute when the engine running and none at all when the engine is off. Nautiqueparts.com has the cheapest prices and reasonable shipping. Here's an excellent article regarding this subject
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I replaced the original bronze stuffing box with new bronze stiffing box an 6 ply hose. The packing is GFO Gore Tex, naturally lubricated. It drips a little as it is supposed to only when the shaft is turning. Very happy with it. It had been 5 years since I replaced the packing.
I vote for bronze stuffing box.
Visit Stuffing-Box | Catalina 36 MKII Album | Sail La Vie Home
I vote for bronze stuffing box.
Visit Stuffing-Box | Catalina 36 MKII Album | Sail La Vie Home
Replacing the packing is cheap and has works well. In my opinion there is no need to spend a lot of money on a dripless system. I just did this on my boat this winter. Just don't buy graphite impregnated braided material. I learned from Nigel Calder's Boat How To marine diesel coarse (great coarse by the way I highly recommend it) that Graphite is high on the galvanic series table. In the presence of salt water, it can generate significant galvanic corrosion, especially with stainless steel propeller shafts. The ABYC specifically forbids the use of graphite impregnated packing (“Graphite impregnated packing material shall not be used because of the possibility of galvanic incompatibility with the shaft material”)
I've been down both roads, dripless and traditional packing. When I changed from a traditional stuffing box to a PSS the main reason was access to the stuffing box. It was a challenge to access the stuffing box, the PSS was a once in 5 or 6 year event not an annual event. A vent is necessary to avoid burping the bellows.
I do know a person who had a PSS bellows fail. He was able to get the boat out of the water before it sunk.
I do know a person who had a PSS bellows fail. He was able to get the boat out of the water before it sunk.
The one MAJOR reason why I have not gone with a mechanical seal is the requirement to replace the rubber bellows every 7 years or risk the consequences.
Too much hassle with removing the shaft or trusting a split coupling to remain true. And I LOVE tinkering with my engine and associated parts.
Too much hassle with removing the shaft or trusting a split coupling to remain true. And I LOVE tinkering with my engine and associated parts.
I was also turned off by the 7-year replacement interval on the PSS. I ended up going with the LasDrop which does not have a bellows. Instead, it has a heavy-duty silicone 6-ply hose and it will last as long or longer than the rubber hose.
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I’ve been very happy with my Volvo seal which is now 10 years old and still does not drip at all. It does have a vent / water injection tube off the back of the heat exchanger. I lubricate it once per year with a pea sized amount of grease, and burp it once after launching. Grand total for that maintenance is about 5 minutes per year. It’s probably due for replacement soon by the book, and that will be a pain, but Maine Sail has recommended replacing a traditional shaft log hose every 7-10 years anyway.
Just replaced my Volvo shaft seal a few months ago, after 17 years (should replace at 10 years). Really looked good upon replacement; however, engine has low hours. Minimal maintenance & has never leaked nor dripped. As compared to the conventional "stuffing box" on my previous boat, the Volvo is more effective & easier to maintain. BTW, the Volvo replacement cost was approximately $130; I replaced it myself. If done properly it only requires "burping" when splashed after haul out.
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I really like my Volvo dripless seal. As @Project_Mayhem noted, I do burp my seal anytime I go out. My engine intake thru hull is near the stern tube, so when I open the thru hull, I give the seal a little squeeze.
No idea how much air is in there, but there is a little hesitation before water squirts out.
But no leaks, the seal runs cool and it seems pretty robust.
Greg
No idea how much air is in there, but there is a little hesitation before water squirts out.
But no leaks, the seal runs cool and it seems pretty robust.
Greg
Greg,
I watched your Volvo shaft seal video prior to replacing my seal. Very good production & absolutely helped when I replaced mine. Much thanks!
Question, can you get the shaft coupling off to remove the stuffing box? I wanted to take mine off to pull the shaft out and it would not budge at all.
That's the hardest step in replacing a shaft seal. You'll probably need to press it off with some sort of homemade tool. Some people just cut the shaft and replace it along with a new coupling. I was able to press mine off but I bought a new split coupling anyway.
My first boat a Beneteau came with a Volvo seal. 500 Hrs and 12 yrs old when I got it. At 1000 hrs and 16 yrs old the water line fitting corroded and needed replacement. (see picture) At 1100 hrs and 17 years old I replaced it only because it was past due. Seal was fine. This was a nice design for the Beneteau as the cooling water flowed out through the cutlass adding lubrication.
My second boat a Hunter came with packing. Having no experience with this I did a bunch of research. Read it has to drip to lubricate the shaft and if you don't get it right the shaft can over heat. Having a dry shaft area was high priority for me. You can see in the picture how dirty it was and that black stuff was really hard to clean and access is limited. I wanted to put in a Volvo seal but that meant another thru-hull. So I did more research. Maybe good marketing or the area I live in but the PSS kept floating to the top of the list. As I was unfamiliar with it I had it professionally installed. Two summer seasons so far and very happy.
We are coastal cruisers and go from the San Juans up to Desolation sound. If I was going to cross an ocean then I would reconsider. From what I have read packing is the only seal that can be replaced in the water.
My second boat a Hunter came with packing. Having no experience with this I did a bunch of research. Read it has to drip to lubricate the shaft and if you don't get it right the shaft can over heat. Having a dry shaft area was high priority for me. You can see in the picture how dirty it was and that black stuff was really hard to clean and access is limited. I wanted to put in a Volvo seal but that meant another thru-hull. So I did more research. Maybe good marketing or the area I live in but the PSS kept floating to the top of the list. As I was unfamiliar with it I had it professionally installed. Two summer seasons so far and very happy.
We are coastal cruisers and go from the San Juans up to Desolation sound. If I was going to cross an ocean then I would reconsider. From what I have read packing is the only seal that can be replaced in the water.
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I went through pulling my shaft (original bronze from 1988 I assume). I saw some cracks in it, but not sure if they were condemnable (they were), so I wanted to get the shaft off in one piece. Getting the coupling off was by far the worst part of the job…
Once the coupling was off, I got the shaft out and inspected….not good!
I had to replace the shaft, coupling and stuffing box hose.
This was a pretty solid setup, but I still wanted to go dripless…so a year later I removed the coupling and installed a Volvo Penta dripless seal.
Greg
Once the coupling was off, I got the shaft out and inspected….not good!
I had to replace the shaft, coupling and stuffing box hose.
This was a pretty solid setup, but I still wanted to go dripless…so a year later I removed the coupling and installed a Volvo Penta dripless seal.
Greg
Yes, you are right.Check your cutlass bearing for play too. If you decide to change to a dripless seal then you are almost to the point of cutting the strut bearing out. I.e. probably had to drop the rudder to slide the prop shaft back far enough to get the new seal on.
I pressed out my cutlas bearing in order to give me a little wiggle room with the shaft, so I could slide it out without dropping the rudder (when I removed the shaft for inspection, and to get the new one in place).
My bearing was replaced a year or so before I tackled the shaft, so I reused it. I have a home-made bearing removal tool, so it is not a big deal to replace it.
Greg