Adjusting the packing nut frequency

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Palmer King

How frequently should one adjust the packing nut? Every 20 hours of engine runtime? Every 30? While sailing to Key West, the packing started leaking way too much and partially flooded the engine compartment. I'm curious if this was caused by my neglect (it was fine 36 hours earlier when I left port) or an improper installation.
 
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Ron

Some Thoughts

If it was new it should have been readjusted after 3 or 4 hours. If it was older it could have been too tight which will wear the packing out and cause it to leak. I check mine everytime I use the boat. It's not that much of a problem and is well worth it. If it needs to be changed it only takes ten minutes... Ron/KA5HZV
 
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Ralph Johnstone

Even Further Thoughts ..................

............ if you are using a teflon impreganted flax packing as we use, I have not touched it in over 120 hours of operation this season. Also, the packing DOES NOT DRIP. It is just barely tightened to the point where it does not leak and left there. I examined the shaft after 200 hours of running and it still has a mirror polish under the packing. Hope this helps. Regards, s/v Island Hunter
 
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Al

stuffing box

when i bought my boat the packing leaked pretty bad. i knew nothing about adjusting it so i had someone do it for me. they used two wrenches to loosen the locknut and to tighten the packing nut. in a short time it was leaking badly again. the problem (as i learned a little more about it) was the shaft was pitted in that area. as it spun, it chewed up the packing material. i have since changed the shaft,used the synthetic teflon impregnated packing,and only tighten the packing nut by hand, then use the wrenches to tighten the locking nut.
 
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Jack Tyler

More about Ralph's comment...

Palmer, I think Ralph gives you a reasonable benchmark to measure your stuffing box against. Just to emphasize it, we installed the teflon packing he mentions (a green material inserted between 2 rings of flax packing) and put 1300 hours on our engine over 2.5 years while cruising the East Coast and Caribbean. Perhaps 2/3 of that engine time was propulsion (vs. engine charging alone) and I only needed to tighten the stuffing box once. It is difficult for me to rationalize the expense - and sometimes subsequent problems - of 'dripless' add-ons when I get this kind of performance from a $50 purchase that's lasting 4 years after it was installed. I would recommend you buy the right tools, remove the old flax packing at the first opportunity (to insure your shaft doesn't get too scored...) and replace it with the product Ralph & I are discussing. You will then be equipped for doing this with any subsequent boat indefinitely and, in the meantime, enjoy the service good packing should provide you. And BTW, doing this when when the boat is on the hard is a lot easier if doing it for the first time. Good luck! Jack
 
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andy

More Jack's thoughts

I used the green "Dripless Packing" for 2 years with NO LEAKING. Last winter winter I had the shaft out and replaced the stuff with the rest of what was in that $50 kit.(enough to do my 1" shaft twice) This time I used GFO (Goretex) instead of flax for the back up rings. Very happy with the green teflon product. PS I just don't trust the bellows on the mechanical seals.
 
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Ron

My experience

The first season on my new boat had barely a drip/minute (within spec). The second season found the shaft packing dripping at a higher rate (2-3 drips per second) than comfortable. It was stable, but the constant working of my bilge pump finally forced me to tighten it a bit. No problem since. I suspect there were minor differences in hull flexing as a result of the winter haulout/spring dunking that caused it to occur. This now goes onto my Spring commissioning checklist. I also check the drip rate every time I go aboard. Since the shaft packing is right next to my fuel & seawater cooling filters, it becomes an easy thing to remember. PS: It may be stating the obvious, but repacking the seal should be done with the boat OUT of the water. :) --Ron
 
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Tom

Andy, I know you like the green stuff

But what are your feelings on the GFO in comparison. I have the GFO stuff and I am relatively happy with it.....any comments?
 
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Ralph Johnstone

Back to Jack Tyler ...............

.......... I know the product you are referring to which is a green pliable teflon mixture. I have used the stuff in relatively slow industrial pumps and it is second to none. However the packing I refer to is quite simply 3/16" teflon impregnated flax braided packing with which I am still quite incredulous as to its performance. The only reason I have yet to use the "green stuff" is due to my Scottish ancestry. The commonly obtained packing we get off the shelf is still, I'm told, tallow impregnated flax which dates back about 100 years. Teflon has brought the soft flax into the 20th (or is it the 21st) century. Your last remark sums it all up ........... "It is difficult for me to rationalize the expense - and sometimes subsequent problems - of 'dripless' add-ons when I get this kind of performance from a $50 purchase that's lasting 4 years after it was installed." Add to that the slight but real possibility of catastrophic failure of the mechanical seal and it just doesn't make sense. Enough ramblings ........ it's a beautiful day meant for sailing and not musing on the benefits of teflon packing vs. mechanical seals. Regards, s/v Island Hunter
 
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