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bruceyp 05-11-2008 09:58 PM

After re-stuffing the box....
 
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!)

Maine Sail 05-11-2008 10:44 PM

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.

Sapperwhite 05-11-2008 10:48 PM

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).

bruceyp 05-12-2008 08:17 AM

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

Maine Sail 05-12-2008 08:23 AM

Quote:

Originally Posted by bruceyp (Post 312994)
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?

SEMIJim 05-12-2008 12:21 PM

Quote:

Originally Posted by bruceyp (Post 312994)
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.

Quote:

Originally Posted by bruceyp (Post 312994)
I was only able to turn the nut back on a little bit, maybe a full turn or so.

This sounds wrong.

Quote:

Originally Posted by bruceyp (Post 312994)
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.

Quote:

Originally Posted by bruceyp (Post 312994)
But I thought it would "seat Itself" as it was run.

I think maybe you're not grokking how the packing gland works.

Quote:

Originally Posted by bruceyp (Post 312994)
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

bruceyp 05-12-2008 05:26 PM

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?

sailingdog 05-12-2008 06:25 PM

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.




Maine Sail 05-12-2008 09:39 PM

Quote:

Originally Posted by bruceyp (Post 313282)
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..

bruceyp 05-13-2008 07:10 AM

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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