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Old 01-21-2010, 11:40 AM   #21
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stuffing box replacment

We installed the dripless system on Beach House and I have installed hundreds of them over the years. Each time this discussion comes up a parade of information is presented about sinking of boats due to dripless failures and pretty much all of that information is a repeat of something that happened years ago under actual circumstances we know nothing about. As a tech for a very large power and sailboat dealer we have had every new boat come in with the dripless system. Of all of the installations I have done and the boats I have been involved with we have seen no failures ever and on some systems that were over ten years old. We do not check our dripless every hour, every day,and maybe once a month. And when we do check it there is never anything going on. Now we are not stupid and we are always safety oriented in every installation we do. Directly under the dripless is a float switch that is attached to an alarm that can be heard in the next state. So that is why I don't need to constantly do inspections and our second bilge pump is nearby to handle water intrusion from there or any place else. This is one of those decisions that needs to be made by the skipper depending on there preferences and comfort levels. For those that think they are a disaster waiting to happen, by all means keep it off of your boat, since it is your boat. For those of us that like the system for our own reasons and preferences, install the units or leave them in place. I would never let the fear factor drive me to spend needless money and make changes to the boat, but then that is just me. Some of us have to make our own decisions when it comes to equipment. Too often when we come to these boards for info, what we get are the opinions and prejudices towards certain equipment, boats or whatever, rather than first hand feedback that will allow us to make informed decisions. The PSS system is one piece of equipment that generates this kind of discussion. Chuck

-- Edited by Capn Chuck on Thursday 21st of January 2010 12:40:48 PM
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Old 01-21-2010, 11:41 AM   #22
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stuffing box replacment

I agree the dripless has pluses and minuses just like the old stuffing box.* Its not like the bellows are just going to fail, if you check on them every time you pull just the old one.* The bellows should/would show some sign of leaking/weeping.* I have blue paper towels under the dripless so if there is one drop it will be noticed when the boat is docked/stopped.* If it did start leaking I would take Saharan/plastic wrap stuff it in the hole to make a temporary plug and/or wrap the plastic around the bellows which should stop or at least slow the flow.
*
Another reason I installed is the dripless is more forgiving if the shaft is tweaked/bend.* The bellows can move up and down about " and still hold a seal.* I also installed double 3700 gph bilge pumps with alarms plus have a portable 2000 gph bilge pump, which should more than keep up with the flow.** I am more concerned about the 2" DD 671 raw water hoses leaking/braking as they are under pump pressure, where as the water pressure on the bellows is small in comparison.
*
Our bow thrust blew hole, so I took Saharan/plastic wrap stuff some in the hole wrapped it with the plastic wrap and duct taped.* Lasted 2 day until we could get pulled with no leaks as it was 2 ft under water with little water pressure.* *Also installed two 3700 ghp bilge pumps in the bow. **So weigh the pros and cons and if concerned have checked every time you*are in *the einge room, have checkevery time you*pull, install extra bilge pumps which can not hurt, and have a back up plan as stuff happens.*



-- Edited by Phil Fill on Thursday 21st of January 2010 12:42:55 PM

-- Edited by Phil Fill on Thursday 21st of January 2010 12:44:42 PM

-- Edited by Phil Fill on Thursday 21st of January 2010 01:08:32 PM
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Old 01-21-2010, 12:48 PM   #23
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RE: stuffing box replacment

Quote:
Capn Chuck wrote:

We installed the dripless system on Beach House and I have installed hundreds of them over the years. Each time this discussion comes up a parade of information is presented about sinking of boats due to dripless failures and pretty much all of that information is a repeat of something that happened years ago under actual circumstances we know nothing about. As a tech for a very large power and sailboat dealer we have had every new boat come in with the dripless system. Of all of the installations I have done and the boats I have been involved with we have seen no failures ever and on some systems that were over ten years old. We do not check our dripless every hour, every day,and maybe once a month. And when we do check it there is never anything going on. Now we are not stupid and we are always safety oriented in every installation we do. Directly under the dripless is a float switch that is attached to an alarm that can be heard in the next state. So that is why I don't need to constantly do inspections and our second bilge pump is nearby to handle water intrusion from there or any place else. This is one of those decisions that needs to be made by the skipper depending on there preferences and comfort levels. For those that think they are a disaster waiting to happen, by all means keep it off of your boat, since it is your boat. For those of us that like the system for our own reasons and preferences, install the units or leave them in place. I would never let the fear factor drive me to spend needless money and make changes to the boat, but then that is just me. Some of us have to make our own decisions when it comes to equipment. Too often when we come to these boards for info, what we get are the opinions and prejudices towards certain equipment, boats or whatever, rather than first hand feedback that will allow us to make informed decisions. The PSS system is one piece of equipment that generates this kind of discussion. Chuck

-- Edited by Capn Chuck on Thursday 21st of January 2010 12:40:48 PM
Chuck
** My boat is simular to yours. In replacing the stuffing box how did you suppot the stern tube?Is this instillation covered in your blog?* Thanks

*
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Old 01-21-2010, 12:52 PM   #24
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RE: stuffing box replacment

We did cover it here with some photos,
http://tinyurl.com/y87qagq
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Old 01-21-2010, 02:48 PM   #25
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stuffing box replacment

The problem is I can not get the packing to live. Looking at Chucks blog I maybe know why. I have a set up simular to his except my stuffing box has NO water feed. Is a water feed normal on a trawler with a stern tube My stern tube is below the water line but 53'' from the cutlass bearing. Running down the ICW for 10-12hrs a day I have to tighten the packing gland every day ,then after 2 weeks or so the packing is mostly gone and needs replacment I have tried several types of packing with no real difference Is a water supply to the packing the solution?

-- Edited by motion30 on Thursday 21st of January 2010 03:50:46 PM
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Old 01-21-2010, 03:45 PM   #26
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stuffing box replacment

The shaft was out of the boat 2 years ago* It was straight at that time My marina checked the aligment 2 months ago and stated it was OK said the shaft looked good as well But there is a problem No unusual viberations as far as I can tell The marina also said I should have a rag joint at the flange Where to start?


-- Edited by motion30 on Thursday 21st of January 2010 04:46:20 PM
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Old 01-21-2010, 04:47 PM   #27
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RE: stuffing box replacment

Quote:
motion30 wrote:

I have tried several types of packing with no real difference Is a water supply to the packing the solution?
I don't think so.* Some boats with conventional packing glands (like ours) have water feeds and some don't.* Whether they do or not is dependent upon how much water gets back up into the shaft log when the boat is underway to cool and lubricate the cutless bearing(s) in the log.

From your description it sounds as though your packing material is shot unless there is some other problem--- alignment, vibration, bent shaft, etc.--- as fishboat described.

*
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Old 01-21-2010, 04:52 PM   #28
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RE: stuffing box replacment

We had a similar problem with our previous boat and the exact same stuffing box as the trawler. We also found that using the trawler always required some adjustment to the stuffing box after running for a while. So that is why we decided to switch to the dripless system. You may find the problem is in the adjustment bolts which tend to loosen after running for a while and have nothing to do with the packing. Chuck
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Old 01-21-2010, 05:35 PM   #29
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RE: stuffing box replacment

Quote:
Capn Chuck wrote:

You may find the problem is in the adjustment bolts which tend to loosen after running for a while and have nothing to do with the packing. Chuck
If your stuffing box is fitted with a large adjustment nut that completely surrounds the entrance to*the stuffing box, there should be two of these nuts together.* On our boat the rear one is the locknut and the front one is the actual packing adjustment.* We've owned our boat for almost twelve years and had the packing changed once, about two years ago when we had the shafts out.* Between buying the boat and two years ago the packing nuts on one shaft need adjusting once and the nuts on the other shaft never needed any adjustment.* After the boxes were re-packed two years ago, there was a period of trial-and-error adjustment to get the right shaft log temperature but once that was accomplished we have not had to touch the adjustment on either shaft*since.* So what you are experiencing is not normal at all in*our experience.*

If your boat has this "large nut" arrangement but does not have the second, locking nut, that could be the source of the problem since the adjustment nut could easily back off with vibration.

The other kind of packing adjustment I have seen is a collar that fits around the stuffing box and is tightened down with a pair of smaller bolts on "ears" on either side of the collar.* I do not recall if this system uses lock nuts or not--- I would think it would.
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Old 01-21-2010, 06:41 PM   #30
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RE: stuffing box replacment

Quote:
oldfishboat wrote:

Marin Invader no 1 has the two bolts either side for adjustment. Man is it ever nice compared to the big nuts* < grin >. And yes they have locking nuts.


I can see where the two-nut system like yours is easier to deal with than the large nut system like we have.* In our case I slathered a ton of grease and anti-seize on the big*nuts so that when they do need adjustment they are at least a little easier to separate.* But in an area of limited space, which is the case on our boat, getting a large enough wrench on them is a real pain, and the little "packing gland" wrenches they sell for this purpose are next to useless.* Assuming the adjustment system you have is as effective as the "big nut" system, I woud prefer your system.

*
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Old 01-21-2010, 06:50 PM   #31
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RE: stuffing box replacment

Quote:
Capn Chuck wrote:

We had a similar problem with our previous boat and the exact same stuffing box as the trawler. We also found that using the trawler always required some adjustment to the stuffing box after running for a while. So that is why we decided to switch to the dripless system. You may find the problem is in the adjustment bolts which tend to loosen after running for a while and have nothing to do with the packing. Chuck
*Thanks Chuck
**** I do have double nuts on the stuffing box and after 2 weeks or so running 10hrs per day Iam out of thread and need to replace the packing... Chuck in you pictures of the dripless system you have a new flange on your old stuffing box that accepts the bellows* Where did you get it?
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Old 01-21-2010, 07:23 PM   #32
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RE: stuffing box replacment

motion, That is not a new flange, it is the old or original flange reversed. Chuck
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Old 01-21-2010, 10:27 PM   #33
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RE: stuffing box replacment

Old Fishboat wrote -

I have no water feed tube on my system. I do have a grease fitting however.
But no its not uncommon to not have a water feed.
--------------------------------------------------------------------------------------------------------------
This same system is on Penta and the packing has only been replaced once in the 20 odd years she has been in our hands. This happened 15 years after we got her and was done while I was replacing the cutlass bearing, not because it was needed, rather a complete overhaul of the shaft system plus it allowed me to see what sort of shape the shaft was in where the packing rides.
When running I make a point to give the grease fitting a couple of squirts about once a week and the box runs cool with no water leak when running and drips about a cup a week when at the dock.

John Tones
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Old 01-23-2010, 10:59 PM   #34
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RE: stuffing box replacment

Following this thread along a bit, we went out for 8 straight days over Xmas - New Year, and circumnavigated Moreton Bay, off Brisbane, here in Queensland, Australia (Google it - it's an interesting Bay).* Anyway, we must have run up about 200 nm, (Clipper (CHB) 34, with original, basically untouched, (head & block), Lehman 120.* Used no detectable oil (take note Marin if you're [img]download.spark?ID=649328&aBID=115492[/img][img]download.spark?ID=649329&aBID=115492[/img][img]download.spark?ID=649334&aBID=115492[/img][img]download.spark?ID=649335&aBID=115492[/img]lookin'), and to my amazement, virtually no water in the bilge.* Why is this interesting?* Because I don't have a dripless seal, but did have the stuffing box re-packed nearly 2 yrs ago with the new teflon based material, and it has basically turned it into a dripless seal, but with the added bonus of the simplicity, and no fear of a cooling feed tube coming adrift and pumping water in, instead of out. A new muffler was also installed.* The blue thing which gets in the way a bit, sorry.* The other relevance to this discussion was the manner of tensioning my stuffing box, being as mentioned by some, a flange with adjusting locking nuts on either side, rather than one large circumferential nut, and the fact I happened to take a before and after photo when it was done.* Which I will now attempt to post, but bear with me if it does not work, as I'm a bit new to this particular forum, but hey....if I can make PMM work........

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Old 01-24-2010, 12:13 PM   #35
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RE: stuffing box replacment

Wow - It looks really neat and tidy!
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Old 01-29-2010, 06:12 AM   #36
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RE: stuffing box replacment

If you're constantly using up packing and getting drips, you probably have a scored or pitted shaft that is eating up the packing. I use the Gore GFO packing which is essentially dripless and forever once you do the initial adjustment. http://www.gfopacking.com/
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Old 01-30-2010, 09:14 AM   #37
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RE: stuffing box replacment

Keith
I had the shaft resurfaced looked great when installed but the packing has not lasted since . I did look at the shaft when I lasted repacked it and it looked good I had my home marina check the motor alinement they said OK but I am going to have a look at it myself
My setup looks much like Peter B. picture with the exception of the hose, my stuffing box screws right to the stern tube thus is solid mounted No room for a dripless system
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Old 01-30-2010, 09:48 AM   #38
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RE: stuffing box replacment

Check to see if the shaft is wobbling while turning. There are fancy gages to do this, but just hold a pencil or something right next to it while turning and see if the surface is moving back and forth. That could be causing the wear on the packing. You might also switch to Gore's GFO packing to see if that works better. I put that in mine around 2002 and has been perfect ever since.
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Old 03-01-2010, 09:54 PM   #39
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RE: stuffing box replacment

Quote:
RickB wrote:

*

I work with the latest and best world class yachts where money is*barely an issue when it comes to the machinery installation.*None of these boats use a seal that cannot be closed off, either by an inflateable bladder or by clamping down on some other type of emergency seal.


Show me another*item below the waterline on a boat where the only thing between the sea and thee is a very thin and very flexible rubber bellows with no way to stop flooding when it fails.

"My PSS dripless systems are working fine and get inspected for temp and leaks every hour I'm cruising. I'd guess far moreso than any standard system gets checked in*most vessels."

That's because other systems can be trusted to behave themselves and don't require that much labor.


-As the owner of two dripless seals, I followed this thread with interest.* When I read the following USCG document, I thought others might also find it interesting.* ...........Arctic Traveller

www.arctictraveller.com

Improper Assembly of Shaft Seals

This document presents lessons learned during a casualty investigation. It
provides useful information for marine inspection and investigation
personnel in addition to owners and operators of Towing Vessels and other
vessels having similar characteristics.

Recently a towing vessel nearly sank while conducting vessel assist
operations in San Juan harbor. A large volume of water flooded the engine
room when the vessel applied astern propulsion. Within a few minutes,
severe flooding filled the engine room with twelve feet of water.
Fortunately the Master was able to intentionally ground the vessel to avoid
sinking.

An investigation revealed that the water had entered through a gap between
the vessel's shaft seal and its mounting flange. When the vessel applied
astern propulsion, the force of water was directed down the shaft towards
its seal thus dislodging it from the flanged mounting / mating surface. The
vessel had recently installed a Kobelco brand dry shaft seal during a yard
period. Installation required a new flanged mounting welded to the vessel
structure.

The mounting flange had been tapped for the use with M20 metric bolts.
During installation the seal was secured to its mounting flange with eight
inch diameter (nominal size) bolts. The differences in the diameters of the
tapped hole for a inch bolt and a M20 bolt is quite small and the pitch of
the threads are very similar. Because of these similarities the use of a
inch bolt into a 20M metric tapped hole may go unnoticed.

In this instance, the improperly fitting bolts eventually loosened and
allowed the seal assembly to separate substantially from the flange mounting
surface when astern propulsion was applied. Post casualty, the owner /
operator reinstalled the proper bolts and enhanced the installation with the
use of a locking device to prevent future loosening.

"Human error" likely resulted in the selection and installation of improper
bolts. Inadequate "situational awareness" may have contributed and failed to
provide the proper "defenses" to prevent the casualty. Careful and routine
machinery space rounds by competent persons and attention to critical areas
like shaft sealing arrangements may have detected the initial loosening of
the bolts and leakage occurring at the seal.

The Coast Guard strongly recommends that owner operators of vessels
utilizing Kobelco shaft seals or similar devices ensure that the proper
fasteners are used. Further, critical inspection of machinery should take
place anytime modifications are made and regular inspection of important
areas such as shaft seals, skin valves, sea chests and other hull
appurtenances should be part of a daily machinery space rounds onboard any
vessel.

This document is provided for informational purposes only and does not
relieve any domestic or international safety, operational or material
requirement. Developed by the Headquarters Office of Investigations and
Analysis and the Investigations Division, USCG Sector San Juan. Shaft seal
questions can be addressed to LT Sarah Geoffrion, Chief of Investigations at
Sarah.J.Geoffrion@uscg.mil. Other questions can be addressed to Mr. Ken
Olsen at Kenneth.W.Olsen@uscg.mil. <table width="100%" border="0" cellpadding="10" cellspacing="5"><tbody><tr><td></td></tr></tbody></table>
*
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Old 03-02-2010, 04:07 AM   #40
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RE: stuffing box replacment

An additional hassle is on some boats , going into reverse the output flange will pull in almost 1/2 inch.

OK if the bellows are set for this otherwise you get a nice spray everywhere.
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