Stuffing Box Issue

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NightCrawler

Senior Member
Joined
Feb 17, 2016
Messages
211
Location
USA
Vessel Name
Previous owner GB 42 Classic
Vessel Make
Currently running a 23' CC
Stuffing boxes drip a bit. One about a drop every 3 seconds not running, more under way. Was going to snug just a tad. One turn on the aft side lock nut and it crumbled.
Now what? Repack and new nutz? LockTite the compression nut until we pull out - wasn't planning to for several months. Thoughts?
 
Not a big problem. Get 4 new nuts and change one side at a time. The gland follower won't move very much this way. After replacing, make sure you keep them even and default to the loose side. Too tight and the packing will overheat.
Sorry, reread your post and realize you have the self aligning, spud type. Disregard the previous.
 
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Crumbled??? Take some scotch brite to what's left of the jam nut. Pink or yellow? If pink, worry. Was everything covered in verdigris? Wire brush, scotch brite and 320 grit everything in sight. If it's green it goes. Anymore pink and you're on borrowed time.
 
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Big fear, will the packing blow out when I back the plate off. Has to come all the way off to replace the lock nut.
No pink anywhere. Lots of green.
 
Big fear, will the packing blow out when I back the plate off. Has to come all the way off to replace the lock nut.
No pink anywhere. Lots of green.
The packing will be in the big nut. Will not blow out. Worst case is the nut backs all the way off and leaks badly. Almost as bad is the nut tightens, overheats the packing and scores the shaft. Improvise something to prevent the nut from turning like a big hose clamp and SS wire until your haulout.
 
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While inspecting note the size of the packing and replace it with modern packing, Duramax or similar.

No more need to drip while underway and annoying dripping when stopped.
 
to be clear

Original post was from my fone and the pic didn't show up. Just to be clear, I can remove the compression plate and get a new lock nut behind it, re-install and not have everything blow out in the meantime. . .
 

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I assume you’re talking about the ss inner nut on the right? That happen to use on our old ChrisCraft. No big deal. Just make sure the bilge pump is working first and have a rag ready ready to help slow down the flow. Another set of hands standing by might be a good idea just in case.
 
No harm in waiting. Daily inspection item. As long as the both nuts stay put on the starboard side the gland is not going anywhere.
 
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is there any harm in having both nuts on the outside . mine are on the outside. if you have enough thread to start a nut it would hold it ,but it probably has enough corrosion to keep it there .if you haven't broken it loose
 
Original post was from my fone and the pic didn't show up. Just to be clear, I can remove the compression plate and get a new lock nut behind it, re-install and not have everything blow out in the meantime. . .

The studs look pretty iffy. Have a good look at the shaft where the corrosion is showing up. The nut disintegrating may be a tell tale for unseen issues.
 
If it were me, I'd stake the exposed threads and wait until haul-out. You can probably stake them with sharp vice grips just by squeezing, so you're not shocking the castings or disturbing the corrosion that's already locking the nut onto the shaft.
 
The odds are that nut is not going anywhere. There is enough tension on it and corrosion or salt in the threads to jam it. If it were subject to a lot of vibration then the nut could be jiggled free but other wise I doubt it.

The threads on the stud where the nut was look compromised also, not good. Could be just the photo.

Schedule a haul out soon and replace not just the nuts but the studs also. Those studs are SS and if seawater is constantly wetting them then it is not surprising the nut gave up. I'll bet it's not 316ss nor is the stud.

Replace ALL the SS bits and use only 316ss .

Even better would be go find some Silicon bronze studs and nuts and I doubt that will happen again. It may mean getting a silicon bronze bolt, cutting the head off and then threading the shank for the needed thread.

If you can't then lots of people can. The yard may have someone or know of a small machine shop nearby to do the job. Just be sure they match the thread in the box main housing as it may be different.

While the boat is out then take Fast Fred's suggestion and use Duramax or Gorflex GFO . Both are good packing which can be set up to run drip free and not get hot. I use the GFO and have done for 10 yrs or so. I don't run it entirely dripless but darn close. It takes a lot of hours to accumulate even a small water puddle.

Or for immediate use , use a vise grip on the unthreaded shank of the existing studs to hold the studs from rotating and undo the nuts.

FIRST: Use a small measuring rule to take measurements at both ears of the pressure ring so you can reset the distance. Remove the outboard nuts, slide the pressure collar/ring back and replace all the nuts and snug it all up resetting to the measured distance/gap.

You night also get new packing and repack the stuffing box. The odds are it is either 1/4" or 5/16". Neither are expensive so get both.
Yes water will come in but the boat won't sink. Just be sure the bilge pump works first as a few gallon will come in.

However, if you do the quickee fix for now schedule that haul out and replace those studs. If that nut failed by crumbling then I'll bet the studs , especially the one that look compromised, won't last. It should be replaced, period.
 
As a separate issue although related I'll make this suggestion.

COVER the shaft entry to the stuffing box with an old, small hacked up fender to stop seawater spray. Any water coming through will be sprayed often travelling quite a distance and causing rusting of other components.

Cut the hanger ear off the fender. Cut a length of fender so it can be held on the stuffing box but overhang the shaft entry. Split the piece lengthwise so it can be opened and installed to cover the shaft entry plus an inch. Use a clamp to secure it to the box body. Just lightly.

Arrange the split to be down. Then the spray will hit the inside, the water will drop into the bilge instead of sending a seawater mist far and wide.
 
Thank all and the PM's for good advice. The other three nuts turn freely and do not appear compromised. C lectric - the PO had done exactly that. Secured it with a huge hose clamp and it was working dandy. Will certainly replace that shield as well.

If I do pull the pressure ring to put a new lock nut on behind it, I'm sure it will leak a bit. Any chance all the packing will blow out as well? Or does it just leak more until the pressure ring is re-installed?

Good advice on measuring the current position of the ring. I have a micrometer and that will work dandy for that measurement.
 
Thank all and the PM's for good advice. The other three nuts turn freely and do not appear compromised. C lectric - the PO had done exactly that. Secured it with a huge hose clamp and it was working dandy. Will certainly replace that shield as well.

If I do pull the pressure ring to put a new lock nut on behind it, I'm sure it will leak a bit. Any chance all the packing will blow out as well? Or does it just leak more until the pressure ring is re-installed?

Good advice on measuring the current position of the ring. I have a micrometer and that will work dandy for that measurement.


When I had a dribble, instead of a drip, I bought new packing and a hook made for pulling out the old packing. LOL, I wasn't able to penetrate the old packing enough to hook even a single thread of it. I did have lots of room inside the recess, so I added a single wrap of new packing and tightened it up. The drip was at exactly the rate that I was seeking. a couple of years later I had the shafts out to replace the Cutless bearings, so the old, old packing came out then.
While doing the job that I was able to do, only a very small amount of water dribbled into the boat, not much more than what was dribbling before the collar was loosened. Yours will likely not be packed as tight as mine, but I wouldn't expect the dribble to be alarming.
If you are able to do so, at least twin and preferably triple rings of new, with the joints staggered is required.
 
:thumb:
 
Greetings,
Mr. NC. We also have the two nuts, locked against one another, on the outside of the pressure ring similar to what I suspect Mr. t has (post #10). On thinking about it, this method may be better than one nut on each side of the pressure ring. The pressure ring is able to "float" rather than being held captive by the locked nuts. From the looks of your photo, you won't be able to do that currently (not enough threads left on the outside). Could be there is TOO much packing in the box. When you re-pack, you might be able to adjust the amount of packing to allow the pressure ring to seat more deeply into the box thus allowing the two nuts on the outside technique.

In any case, the advice you've received thus far is valid but one suggestion...IF you are going to repack while in the water, pre-cut your packing material before you start on disassembly. Use the prop shaft as a length gauge and cut the ends of the material on an angle.

Edit: Mr. Cl raises a VERY valid point (post #13) about the threads on the stud vs the threads in the box. Ours are different.
 
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Hello. I'm not very smart but does the shaft looked pitted to anybody else? I wonder what it looks like where we can't see it?
 
Replacing packing in the water is no big deal. If the nuts turn already, and the stud does not show obvious crevice corrosion, which is likely wha caused the nut to disintegrate, again no problem. Get a wire brush in there and see if the crud cleans off. I don’t see a completely obvious crevice issue on the stud, think it can be serviced. No way I’d add packing to an old crusty gland with almost certainly hardened packing. People worried about maintaining these things is how they get old like this.

Buy a couple corkscrews or three, cause if the packing is ancient, good chance you will break at least one. Get that old packing out of there. Glands should not drip at rest. It won’t “blow out”. In fact, you will have to wrestle to get it out. Not a bad idea to have a cheap mirror to ensure you got all of it too. Worst case scenario, you can stuff a rag or even paper towels in there and stop any flow and go shopping for hours. Usually with the entire packing removed, you will laugh at how little flow there really is and understand why “blowing out” is just not a real concern. It’s completely manageable unless your bilge pump is in a dangerous condition, if so, fix that.

I can’t really say whether that shaft is in bad shape, the can develop a bunch of crud and that’s all it is. I’m worried about the shaft being severely scored under that packing. If it is, it will never really seal right but better to get fresh packing in for now anyway. Also, if the alignment was off, prior owner almost certainly overtightened in false attempt to solve and packing will be like a rock.

Got to stop telling people to tighten glands as the primary means of stopping dripping if they don’t know the condition of the packing and alignment. Causes more problems than it solves.
 
Update - I left it with Locktite Blue for the last two long days running and it's holding fine.
However, now - Port side stuffing box is no longer leaking (totally unrelated other than the Boat Fairy took a peek at something that WAS working and cast her spell) My question for the one NOT leaking - if there is good raw water cooling coming to the stuffing box, and it's not leaking - should I worry? It used to drip just a few drops a minute idle, and maybe double that when running. Just stopped this week.

Thanks to all for the help.
 
Update - I left it with Locktite Blue for the last two long days running and it's holding fine.
However, now - Port side stuffing box is no longer leaking (totally unrelated other than the Boat Fairy took a peek at something that WAS working and cast her spell) My question for the one NOT leaking - if there is good raw water cooling coming to the stuffing box, and it's not leaking - should I worry? It used to drip just a few drops a minute idle, and maybe double that when running. Just stopped this week.

Thanks to all for the help.

Is the box/shaft getting hot? If not leave it alone. Don't fix something that is working...
 
ASD - not sure. Should have checked it sooner after we stopped. That would be the one big concern I'd think.
 
I can crawl back to mine and touch the housing while I am running.
 
I can crawl back to mine and touch the housing while I am running.

I would just caution anyone about getting near a spinning shaft. One brief moment of inattention (or an unexpected wake or wave) and any bit of clothing, hair, etc. will be spun around the shaft faster than a person can react. Some of the most horrible accidents I've ever seen were on farms where someone got a bit too close to a spinning power takeoff shaft.

I'll put mine in neutral mid-trip and go down below to feel the stuffing box.
 
I would just caution anyone about getting near a spinning shaft. One brief moment of inattention (or an unexpected wake or wave) and any bit of clothing, hair, etc. will be spun around the shaft faster than a person can react. Some of the most horrible accidents I've ever seen were on farms where someone got a bit too close to a spinning power takeoff shaft.

I'll put mine in neutral mid-trip and go down below to feel the stuffing box.

4 years as a first responder. I hear ya. Watching that thing turn actually makes me ill, thinking of those calls.
 
Wear nothing but your underwear. That should eliminate the problem???
 
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