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Discussion Starter #1
I followed the instructions on the following link Re-Packing A Traditional Stuffing Box Photo Gallery by Maine Sailing at pbase.com) and restuffed my box last month. Today I motored around for the first time since launching, and of course wanted to check the number of drips per minute to see if I needed to tighten up the nut or what? What I found though was a pile of blobs of what I thought were grease, maybe wax, piled up below where the shaft comes out of the nut. The first time I checked there were 2 or 3 blobs piled up. The second time the blobs were piled up right to the shaft. As the current was running against us and the channel not too wide I didn't want to shift into neutral to feel how hot the nut was, and I forgot to check it out once we were moored. Is this a normal thing that happens to a newly packed stuffing box? By the way, I saw no water drips.
Thanks for your help.
Bruceyp of the Hannah Lee (So Happy to be back in the water!)
 

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Bruce..

Bruce,

That is NOT normal. What packing material did you use? As I stated in my article there should be some drips even when using Gore GFO when the shaft is spinning. It sounds to me like you've over tightened the nut but without knowing what the packing material is I don't have any idea what the goop is..

When initially installing the rings of packing LIGHTLY tighten the nut BY HAND just until you start to feel some resistance then stop! DO NOT OVER TIGHTEN THE NUT.. EVER!! The final adjustment will be made after running the motor and shaft for a while.
Proper adjustment for GFO is up to a few drops per minute when the shaft is spinning. You'll want it adjusted for nothing more than slightly warm to the touch after the shaft has spun for a while. Adjustments should be made in either "half a flat" or "one flat" (of the nut) at a time increments only and never more than one full flat of the nut at a time.
When adjusting other types of flax the stuffing box should be relatively cool to luke warm, at most, and will drip and should drip while the shaft is spinning. Some boxes will even drip when the shaft is not spinning and this is entirely normal depending on the condition of your shaft. Do not get in the habit of tightening the stuffing box when "leaving the boat"! The flax packings are not elastic and do have a memory, in a sense, and they will not necessarily return to their uncompressed state. Doing this will severely shorten the life of your packing and it will start leaking continuously in short order. Traditional flax packing should drip about 5-10 drops a minute if adjusted correctly, while running, and this drip rate allows lubrication of the shaft. Do not make adjustments to packing nut for at least 24 hours as the packing will swell and overheat the stuffing box. Pre-mature tightening of traditional flax can result in potential damage. A good rule of thumb is to adjust the packing by "half a flat" turns after two hours of use or until you have 5-10 drops per minute.
 

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No drips means you have the packing nut too tight. The blobs might be the remnants of the packing you are melting down. Be careful not to tighten the nut too much, you can damage the prop shaft (wear into it).
 

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Discussion Starter #4
Halekai,
I used the flax packing. I was only able to turn the nut back on a little bit, maybe a full turn or so. The nut seemed pretty full after putting the 3 rings on. But I thought it would "seat Itself" as it was run. After this nor'easter passes I will go cruise around and feel the temperature of the nut and actually feel what that stuff feels like.
Thanks, for your input.
BP
 

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Halekai,
I used the flax packing. I was only able to turn the nut back on a little bit, maybe a full turn or so. The nut seemed pretty full after putting the 3 rings on. But I thought it would "seat Itself" as it was run. After this nor'easter passes I will go cruise around and feel the temperature of the nut and actually feel what that stuff feels like.
Thanks, for your input.
BP

If you used regular flax that goop is a mixture of shaft metal and wax? It's way to tight! How many rings came out? What is the boat and did you possibly use the wrong size packing?
 

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Halekai,
I used the flax packing.
Recommend when you re-pack again (as I'm guessing you almost certainly will be doing) you use either Gore GFO or Gore GTU. (The latter is available at West Marine.) It's about three times as expensive, but is reported by all that have used it to be far superior to ordinary flax packing.

I was only able to turn the nut back on a little bit, maybe a full turn or so.
This sounds wrong.

The nut seemed pretty full after putting the 3 rings on.
So did mine, but the material (Gore GTU) compressed very easily after I got the nut started. I had to turn quite a number of turns before encountering any appreciable "resistance." I then backed off and re-tightened more gently until the nut was just barely kinda almost not quite snug. I then tightened the lock nut only by hand.

When the boat first went in the water I was getting about a drip/second. I snugged 'er down at a drip every six or seven seconds or so. After a short run (less than 15 minutes under power) and a day later, the static drip rate was up to every 15 seconds or so. Next time under power I was getting a drip every 10 seconds or so, plus-or-minus. A day later the static drip rate was up to every 25 seconds.

But I thought it would "seat Itself" as it was run.
I think maybe you're not grokking how the packing gland works.

After this nor'easter passes I will go cruise around and feel the temperature of the nut and actually feel what that stuff feels like.
I wouldn't do that if I were you. It sounds to me like there's too much in the packing gland and it's way too tight. You may be ruining your prop shaft. If you score your prop shaft, you'll never get a packing gland to last worth a damn ever again, regardless of the type of packing material you use.

I would recommend starting over. You need to make sure all the old stuff is out. You need to make sure the new stuff is the right size. You need to make sure you're getting enough water drip when the shaft is running.

All of this is very clearly explained on halekai36's How To pages.

Jim
 

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Discussion Starter #7
Halekia 36,
My boat is a 78 C&C 29. By the time I finished getting the old packing out there was nothing to measure. I just vacuumed up the pieces and went to the yard office. They looked up in some reference and suggested that I use 1/4" Flax. But I know that there were 3 distinct layers that came out.
Do you have any idea what the correct size is? I know that the shaft is 1" dia. I will get out to the boat tomorrow and get a finger full of the goop and see what size the nut itself is. Will that help in figuring out the correct size packing to use?
And now that I am back in the water, can I replace the packing with the Goretex stuff without sinking my boat?
Again thanks for the help.
I guess this is all being filed as "experience being the best teacher."
By the way I replaced this packing because it stopped dripping. Was that a mistake too? ie. if it ain't broke don't fix it?
 

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IF the packing stopped dripping, it was probably running dry and scoring the propshaft as a result. Have you examined the propshaft where the stuffing box is located? Chances are it is scored.
 

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Halekia 36,
My boat is a 78 C&C 29. By the time I finished getting the old packing out there was nothing to measure. I just vacuumed up the pieces and went to the yard office. They looked up in some reference and suggested that I use 1/4" Flax. But I know that there were 3 distinct layers that came out.
Do you have any idea what the correct size is? I know that the shaft is 1" dia. I will get out to the boat tomorrow and get a finger full of the goop and see what size the nut itself is. Will that help in figuring out the correct size packing to use?
And now that I am back in the water, can I replace the packing with the Goretex stuff without sinking my boat?
Again thanks for the help.
I guess this is all being filed as "experience being the best teacher."
By the way I replaced this packing because it stopped dripping. Was that a mistake too? ie. if it ain't broke don't fix it?
To know the proper diameter of the flax use a set of calipers and measure the inside ID, thread to thread, of the female nut. then subtract 1" (your shaft diameter. You could have either 3/16" or 1/4" but the only way to know is to know the ID of the nut then subtract the shaft. It sounds like you may have a 3/16" stuffing box for a 1" shaft.

As I stated in my article regular flax packing has ZERO memory meaning it will NEVER rebound after being over compressed. It also absorbs moisture and will "grow" once in the water. this is why you need to adjust it over time. Gore GFO on the other hand will compress more and allow more threads because it is NOT wax impregnated. It will also not absorb water like traditional flax so adjustment is more predictable.

What ever you do DO NOT over tighten after the initial installation. Adjustment takes time, and break in, but there should ALWAYS be drips when the shaft is spinning and SOMETIMES when the spin drip is correct you'll still have drips at rest. Not ALL situations can be drip free at rest. A lot depends on the condition of your shaft. Never adjust to the at rest drip and always adjust to the "spinning" drip rate..

I would NOT run your boat with the packing adjusted the way it is. It SHOULD be replaced. You got this shaft and box so hot you literally melted the wax in the flax and you may have scored your shaft.

I'd recommend you use GFO as it's quite a bit more forgiving... In this day and age there is no reason to use traditional flax or teflon impregnated flax.. You want the black looking stuff caled Gore GFO or GTU from West Marine..
 

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Discussion Starter #10
H,
SD,
et al,
Thanks again. I will be changing to the GFO this weekend. If I have everything prepared ahead of time ie the rings cut and the ends waxed, and a decent removal tool, a decent installation tool, can I do this in the water? I mean once I back the nut off, are we talking fire hose water streams here? I read somewhere that someone did this and that his bilge pumps easily handled the water. Is this accurate?
BP
 

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H,
SD,
et al,
Thanks again. I will be changing to the GFO this weekend. If I have everything prepared ahead of time ie the rings cut and the ends waxed, and a decent removal tool, a decent installation tool, can I do this in the water? I mean once I back the nut off, are we talking fire hose water streams here? I read somewhere that someone did this and that his bilge pumps easily handled the water. Is this accurate?
BP
Yes you can. A tool I particularly like for this is called Thera-Band. PT's use it and it's stretchy rubber. It comes in different colors, which only denotes the resistance or strength. Simply ask a Physical Therapist to buy about two feet and when you remove the nut wrap it around the shaft and male end of then stuffing box then take a wrap with 3M electrical tape. If you can't find that a roll of wide rigging tape will do or even a cut open bike inner tube.. I don't advise stuffing wax in there as it may not all come out...
 

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Discussion Starter #12
H 36,
I can't thank you enough for your help. And your website is great, too.
As a footnote, I am a wood turner and I plan to turn that installation tool that you made from PVC pipe. 10 minute job. Turn, slice down the length, done.
I'll let you know after the weekend how it turned out.
BP
 

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A fellow club-member told me the amount of water that comes in isn't all that great, and that re-packing the stuffing box in the water isn't all that big a deal. Nonetheless: I would probably find it distracting, at least.

The solution I read about for stopping the water was to put some silly putty or material of like consistency in Saran Wrap or something, and lightly stuff that around the shaft on the male end of the stuffing box.

Jim
 

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Here's how to measure the nut

Measure the ID of thread to thread of the stuffing nut with a set of calipers.

The nut on my old box measured 1.38 inches and I know my shaft is 1". Simply subtract 1" from 1.38" as in:

1.38 - 1 = .38 inches

Now divide this number (.38) by two as in : .38 divided by 2 = .19 inches.

3/16 of an inch in decimals is .1875!! So I know my packing is 3/16 not 1/4 because that would be .25"

 

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Discussion Starter #15
Halekai 36 et. al.
Repacked the stuffing box yesterday, and this is what I found:
First the inside diameter of the nut was in fact 1.5". Which meant that the 1/4 inch packing was the correct size. I checked this a half dozen times with 2 different calipers to be totally certain. An observation, here: Measuring the diameter of the inside of the nut is almost the same as measuring the outside of the male thread that the nut screws onto, No? Except for the depth/height of the actual threads. In my case it was easier to measure the Male threads, than it was to get a true perpendicular measurement from the nut.(Though I measured both to be certain.
When I removed the old packing the inner surface of the packing was discolored, I assume, from overheating which in turn, melted the wax, creating the globs I first saw. Though the shaft was shiny, It didn't feel scored. I had purchased both the 3/16" and the 1/4" GTU packing from WM, so I proceeded to do the removal/ reinstall.
With the Nut loose I was only getting 78 drips a minute, Is this unusual? Should it have been more?
I had already cut the 3 layers of new packing using H 36's method. 2 additional suggestions. To eliminate the unraveling of the GTU material, I wrapped the ends before cutting with 1" painters tape. I also added a layer of duct tape to the 1" dia tube I was using as a mandrill to save the edge of my razor.
This new packing went in much easier than the flax had. I threaded the nut back on without too much pressure, and brought up the locking nut. Motored around and counted about 28 drips /min. Back on the mooring I only got a couple of drips per with the engine off. I will check and adjust as needed.
As a first time boat owner/operator/maintainer, it is a real treat to have a resource like sailnet to refer to.
Many thanks,
BP
 

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An observation, here: Measuring the diameter of the inside of the nut is almost the same as measuring the outside of the male thread that the nut screws onto, No? Except for the depth/height of the actual threads.
That is correct.. I just find it easy to do the ID...
 

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With the Nut loose I was only getting 78 drips a minute, Is this unusual? Should it have been more?
Define "loose."

When I did our P30 this spring, I used a large-ish-bladed screwdriver to gently initially seat the packing material. Then I gently screwed the packing nut down until the material "felt" pretty much fully seated. (Note: Unless you've worked with a lot of mechanical things over the years, many times blind, this might not be the method for you.) Then I backed the nut off until the packing material felt just barely packed. When our boat first went in the water we were getting a drip per second or better. I snugged the nut down until it was one drip every 7-8 seconds (being very cautious, here, as you can tell) and tightened the lock nut for her 15 minute trip from the launch location to her temporary slip. By the next day the at-rest drip rate was already down to one every 25 seconds or so. With no further adjustments, and after another... I dunno... 1-1/2 hour's time under power, it's down to one every minute or so at rest, all on its own. After about 15-20 minutes into that run, btw, it was at one every 10-12 seconds under way.

So my thinking is: Let the drip rate be a bit on the high side at first and see if it doesn't settle-down all on its own, before tightening further.

As a first time boat owner/operator/maintainer, it is a real treat to have a resource like sailnet to refer to.
Indeed!

Many thanks,
BP
You're quite welcome.

Jim
 
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