Packing questions

[Landsend]

you need to burp the PSS shaft seals

When the diver cleans my hull once a month. I need to burp the bellows on my pss shaft seal because air accumulates in the pocket at the point that the propeller shaft comes out of the hull. This air pocket needs to be removed for the seal to be properly cooled.

 

[walmsleyc]

Now self-burping!

The latest version of the PSS shaft seals come with a hose barb fitting that (for < 12 knt boats) you connect a hose to that runs above the waterline and simply vents. This will allow it to self "burp". On boats faster that 12 knts, the hose is suppose to be connect to a pressure source of water.

 

[NYSail]

Traditional Stuffing box rubber

The hose on the traditional stuffing box is extremely thick....I have never inspected the PSS, however I was told that it is not as thick......My new to me boat (1 year), the Pearson P36-2 has an extremely shallow bilge. The previous stuffing box leaked so much water my coupling was rusted solid. Water was being sprayed all over the aft part of the engine and floor board over the stuffing box. When removing the shaft to have it checked for trueness, I had to cut the coupling off using a drill....not fun! So keeping it dry was very important. My shaft shop, who selling the PSS, recommended I use the traditional stuffing box and just to replace the entire stuffing box and use the GFO flax. Not a drop of water comes through and the shaft and stuffing box stays cool...So far I love this, however I have heard great things about the PSS and was close to buying one.GregP36-2

 

[wrightwmc]

Daryl's Point?

I have had PSS seals on two of my boats and love em!But I have saved an "Outbound 44" from sinking because the rotor had slid forward about a foot and water was just pouring in the shaft log hose. (Knew where to look and what I was looking for.)If the PSS set screws in the rotor are not set properly the rotor can slide away from the shaft log hose. A good saftey device (if you have room) is to install a shaft zinc in front of the rotor or at least a good SS hose clamp to limit how far the the rotor can move away from the shaft log hose.An ounce of prevention . . .Bill

 

[Daryl]

Get Over it

The traditional stuffing box will last fifty years or more with less attention than the high tech expensive PSS type system. I can't believe people spend large amounts of money thinking they are upgrading or improving their vessel reliability or performance. So the teflon flax that lasts ten years or more, costs ten bucks and takes an hour to install. How about that PSS installation? A few hundred for hauling, several hundred to install plus the initial hardware price and you managed to drop a grand or more on something that didn't need to be fixed in the first place. Lets here users tell us how much they spent on his valuable "upgrade". The marketing team gets high honors for selling these. Any idea what is costs to make this item and what the mark up is? (grin)

 

[Ross]

Daryl, I will give you points for Your efforts

to baffle them with BS when you can not dazzle them with brillance. When did rotary shaft seals become "unreliable trash"? Properly installed rotary shaft seals will run for as long as a mechanical stuffing box. Missalignment of the shaft will cause seal failure and shaft failure in both systems. But the rotary shaft seal will give you a drier boat.

 

[Tom S]

Marc from Noank that story years ago was me *sry

At least I think it was. I wrote about it on this forum 6 1/2 years ago. You can read it here with the details. Its similar to to what Bill said about the Outbound 44'. http://archives.sailboatowners.com/pviewarch.htm?fno=20&sku=2000250101229.81&id=45058&ptl=What%20Happens%20IF_%20PSS%20Fails%21%21%21#2000250142527.43Funny how you can really get a skippers' attention when someone says " Honey, is water supposed to be coming over this thing where the engine is?" *yks LOLNo it was not a catastrophic failure, but thank goodness I figured it out. Well its lessons learned and I recommend (as I now think PYI does) a shaft zinc or clamp on the shaft just forward of the stainless steel "rotator" just in case.Now don't get me wrong I think the PSS shaft seal is a great device and if I bought a boat that had one installed I would most definitly leave it in and wouldn't think twice and I'd be fine with it. I totally disagree with Daryll when he says the PSS is junk. It is not, it is a well engineered device. So don't mistake my sharing of information that I know with the "bashing" Darryl is doing. If you really want as close to 100% dry bilge as you are ever going to get the PSS is probably the best you'll get. I have a keel stepped mast, some fresh water leaks and AC draining into the bilge so a 100% dry bilge is never going to happen on my boat anyway People have asked for documented stories and first hand reports so I will relay something I do know, as rare as it might be. This is NOT to say this is a bad or dangerous product but more to get real information out to people so they can be aware and PREVENT issues from happening. Like what was said above, anything on a boat below the waterline can fail, hoses, etc. I even know someone that had a catastrophic failure on his C42 on his one & only bronze thruhull (due to electrolysis) that was put in for his AC while ocean bound from Caribbean to the States. (FYI Most Catalina's use Marelon so even all bronze through hulss are not 100% perfect all the time) So anything can happen and its best to know that 1 in 10,000 chance just in case.So with that said PLEASE DO NOT CONSTRUE the information or stories I am going to share with you in ANY WAY SAYING ANYTHING AGAINST PYI or mechanical seals. Remember nothing is 100% all the time. NOTHING.So here is a few posts I wrote on this very Bulletin Board about another boat owner I knew back in 2002. The name was left out but the owner of the boat (A Catalina) relayed it directly to me. Its not hearsay. Read here to hear what happened.http://archives.sailboatowners.com/pviewarch.htm?fno=20&sku=2002093073945.79&id=129832&ptl=P.S.S.%20frictional%20losses#2002098162719.30http://archives.sailboatowners.com/pviewarch.htm?fno=20&sku=2002280134740.4&id=155007&ptl=Odors/Dry%20Bilge%20questions#2002280201004.23That is one of the MAIN reasons why you don't see PSS Shaft seals without the water injection hose anymore. (Note Look at the picture of "Maine Sails" PSS shaft seal. It has it). As mentioned above, back before 1999 or 2000 you could get slow turning shaft "sailboat" style PSS that did NOT have water hose injection connections. I think they may have a few issues with the "burping thing. They have since discontinued selling that "non water injected" models anymore to anyone no matter what. My guess is there is a reason for that The second point I will bring up is I have heard of something very similar about the rubber bellows ripping because something got caught around the shaft in the engine box area and ripped the bellows. While the PSS Rubber bellows is a VERY tough material I would not say its as thick or tough as the Heaviest duty Trident Heater/Exhaust hose I have on my boat http://www.tridentmarine.com/stage/wetex_hose.htm. Not to mention there is more length of rubber and more exposed rubber in the PSS bellows to getting get damaged than what is actually exposed in a regular packing box installation.The third documented report I just saw about 15 minutes ago. If anyone gets "Seaworthy" (the Boat US Insurance Damage report magazine) just put out their January 2007 issue and on the bottom of page 10 they just happened to have an article on boats sinking and 'Stuffing Box Maintenance'. The very last paragraph talks about mechanical seals (like the PSS) and they have a documented case (claim #0402595) in which a boat sunk due to some sort of mechanical seal failure.I still want to emphasize that they are NOT failure prone at all, and for all we know its 1 in every 200,000 boats that has a mechanical shaft seal problem. I would almost bet ANY amount of money that, many, many, many more boats have sunk at their mooring or on their dock due to an overly drippy traditional packing. Almost happened to me - I went to my old boat on mooring after leaving it 2-3 weeks and there was a 10 inches of water in the salon !!! - You guessed it, drippy traditional packing, thats why I originally went to a PSS mechanical seal back in 1993-94 in my old boat

 

[Tom S]

Alex, I have no doubt lots of big boats use

a mechanical seal. I have heard they have been around a long time especially some water turbine pumps and I have heard in special application areas where leaks are not a good thing they are used (caustic fluid pumps, nuclear power plants). As noted on the PYI site, these PSS shaft seals are A.B.S. ApprovedThough to compare traditional packing to rotary dial phones is totally off base. Traditional packing is used in many applications and is a very cost effective and reliable solution for water pumps. Just check some applications and industries that use it. There are lots of special applications where its regularly used http://www.sepcousa.com/products/packing/ptfe_graph.html & http://www.gore.com/MungoBlobs/1019/592/GIS%206582%20GFO%20DS.pdf They don't have these products or websites because its going out of use. Funny it also says "It's already being used by the US Navy and Coast Guard and many commercial work and fishing fleets. And, it's approved by the American Bureau of Shipping. " on its website http://www.emarineinc.com/products/gfopacking/packing.html

 

[Tom S]

More info from Boat US with stuffing box failures

As I guessed earlier, much more sinkings occur due to traditional stuffing boxes at the dock than you think.Same issue of "Seaworthy" (jan 2007) Boat US study shows that 35 out of 100 boats that have Inboard engines boat that sink at the dock are due to leaking stuffing boxes. Wow. (This exludes I/O's etc that have their own problem) Now that does not proof everything becuase we all know the percentage of boats with traditional packing glands far out number PSS type seals. Not to mention boats with PSS type seals are typically better cared for and the lack of care is why a boat's traditional stuffing boxes will leak at the dock (I know, I know. It happened to me )Though typically when a traditional stuffing boxes goes it goes slowly with a 'drip....drip.....drip" and can be taken care of if you monitor it at all, but when a mechanical seal goes it almost always goes while underway and away from the dock. The worst part is when a PSS shaft type seal goes it goes more than a drip. It goes with a "Gush" !

 

[Maine Sail]

Daryl lets take your points one by one...

Quote: "The traditional stuffing box will last fifty years or more with less attention than the high tech expensive PSS type system."Really fifty years? So I guess the rubber hose on a PSS should be expected to last the same? After all the PSS hose is reinforced with Kevlar and the Trident hose is reinforced with nylon. No one, in their right mind, would dispute that nylon is a tougher longer lasting substance than nylon especially the cops that are protected from bullets by Kevlar vests. There is NO stuffing box in existance that does not require a new rubber hose , which connects it to the hull, periodically or at least every 7 to 10 years. I personally have replaced half a dozen rubber hoses on traditional flax boxes over my 38 years of sailing. The SAME labor is required to replace the rubber hose on a traditional stuffing box as is required to replace or install a PSS. Your point makes NO sense.. Keep on thinking your stuffing boxes hose needs little to no attention and your boat will soon be a crab condo.. Quote: "I can't believe people spend large amounts of money thinking they are upgrading or improving their vessel reliability or performance. So the teflon flax that lasts ten years or more, costs ten bucks and takes an hour to install. How about that PSS installation?"Quote:"A few hundred for hauling, several hundred to install plus the initial hardware price and you managed to drop a grand or more on something that didn't need to be fixed in the first place."How about that PSS installation? Well lets see EVERY boat owner has to remove their boat from the water periodically to paint the bottom. Many sailors live in areas where they haul seasonally anyway. I waited for my winter haul to replace my stuffing box. Patience is a virtue. Additional haul/launch cost = Zero. My PSS also took close to an hour to install like your flax! The process cost me three squirts of PB Blaster @ .40 cents, four 4 1/2 inch bolts from the hard ware store @ $2.65, and 8 inches of seizing wire @ .60 cents. The process is the same as replacing the rubber hose on a traditional stuffing box and is so easy even you could do it Daryl. As for cost a Spartan Metals traditional stuffing box for my boat would cost me $147.00 and my PSS cost me $169.00 so I am glad to to pay the extra $22.00 for a DRY bilge.Any sailor that has to pay a boat yard to install a PSS is perhaps not a knowledgeable enough sailor to be out sailing anywhere other than a bay. Now if that same sailor has the ability to install the PSS and chooses to pay the yard because they have the money, but not the time, that's their choice. There are plenty more mechanicaly difficult systems on a sailboat that a sailor should understand to be self suficient. Installing a PSS is a level 1 install = to the task of making toast! No sailor should be paying a yard to install a PSS unless they don't have the time!Quote: "Lets here users tell us how much they spent on his valuable "upgrade". The marketing team gets high honors for selling these. Any idea what is costs to make this item and what the mark up is? (grin)"I'm an owner and I'll tell you exactly what it cost me. It cost me $172.65 and is worth every penny. The marketing team had NO play in my decision to move to a dripless seal. I sought it out and did not read any glossy adds that made me think "wow I need one of those". The constant stench of a wet bilge and the constant mold infestation is what did it for me.As for mark up what should it matter? For Christ sake you own a BOAT and every manufacturer from 3M to Sea Fit screws the boater. Take for instace the Sea Fit Dog Bone Sponge in the 2006 WM catalong for $5.49. I can buy that same sponge, under a different brand name, at Wal*Mart in the automotive department for .97 cents. Another product "The Absorber", a chamois, on the same page as the Dog Bone Sponge is also sold at Wal*Mart. WM has it for $15.99 and Wal* Mart for $7.99 and this is the identical brand and product. Or how about the 105A Prestolite/Motorolla style alternator on page #231 for $372.50. I bought the same alternator from a local auto parts store, and yes it is marinized, for $176.50. I for one have no problem with companies in this country finding a way to make a buck in niche markets. What did the R&D cost for the PSS? What is the wholesale cost for the item? Unless you know these answers it's tough to judge. Hell the PSS could cost a chandlery less than a Spartan marine stuffing box, you don't know, but because the chandlery know's they can sell it for more, because people like me see a value to the product, they do. Your bitch here is with Capitalism and that's another story for another day and not to mention very hypocritical for a "yacht" owner...Say hi to your other brother Daryl & your other brother Daryl for me will ya...

 

[Scott21120]

Daryl, I can answer your questions

at least for my case. Our boat is an 83, and I have no reason to believe the original stuffing box or hose has ever been replaced (although I AM sure the packing has). Since I am in Wisconsin, the boat is on the hard for the winter. I have the prop shaft out to replace it and the cutless bearing, so I already have access to the stuffing box - unimpeded. My stuffing box is the old variety that takes a special kind of tool - it does not have nuts with flats on them, so it is something of a pain to adjust, and in an effort to stem the drips over the years, it has been overadjusted to the point that my bronze propshaft was badly worn. My PSS system will cost just a little more than Rod's did - $ 183.00. So, my real net cost to upgrade (even IF I didn't do anything about the old stuffing box) is $183.00. As others have mentioned, I really prefer a dry bilge. My boat tends to develop a little odor if I allow water to sit in the bilge, so for me the $183.00 is worth it to keep the bilge drier. I asked you originally if you could give us some examples of what makes the system junk, and also examples of failures you seemed to cite as common. You have not come forth with either, so I am inclined to dismiss your claims as baseless. The fact is that even though we have come up with a couple of examples where there was a problem - none of them were due to a fault with the product - they were problems of operator or installation error. By that standard, the OLD stuffing box in my boat was a failure due to the fact it has ruined my propshaft.--Scott FullerO34 Dawn TreaderMilwaukee, WI

 

[Ross]

Maine Sailor, I believe that you have it

right but Daryl has his mind made up. Confusing him with the facts won't help. From personal experience, traditional stuffing boxes can be neglected for ten years and wreck the shaft and the stuffing box. You just start out with engine beds that will rot. Then you take an "outta sight-outta mind" approach to the engine and let the mounts fail and the engine move. Now the shaft bears on the packing nut and shifts fore and aft when you change gears. This way you get to wear three grooves into the shaft where it should be nice and smooth for the flax-teflon packing. The result is more water on the engine beds and more rot. Seven years ago I replaced the shaft, installed a "Drive-saver" coupling, black locust engine beds and a PSS shaft seal. I look at it each time I check the engine before start-up and it is always just the same , Dry, new looking and comforting.

 

[Daryl]

OK

Ok these are great and I'll buy three for my boat. One to work on, one for spare parts and one to use. My teflon flax is headed to the dumpster