Hot stuffing box, leaky stuffing box. Is there an in-between?

[Pete the Cat]

Originally Posted by stnick

I only use the new GORTEX packing . Its a no drip packing !
I pay special attention to the shaft smoothness. A fine emery paper strip back and forth to polish that shaft. I have a set of dental picks to remove any packing caught up inside that i just cant see. Use the lube ! No sence paying for no drip and having it drip !!
I like it , Have a dry space under the shaft !!!

I have been using the Gortex stuff for many years (I used to get it from a manufacturer for the Navy (nuclear subs do not use dripping shafts, folks and they do not use bellows arrangements either—think about it) before you could buy in in marine stores). No leaks. Dry bilge. Motored more than I would like to admit on taking my boat from San Francisco to Maine via Panama Canal) and never a problem. Trick is to tighten the thing gradually by 1/8th turns until you are just past no drip. Us the Syntef lube. Been doing this for 20 years. No scoring. No leaks. Have no idea why folks make this so difficult.

[EngNate]

Several things important:

Clean tube & nut and smooth shaft surface

Correct packing size - tube dia minus shaft dia / 2

Rings cut so the ends butt together well- no gap & no excess

lubricant as recommended by the material maker - outside and inside the circle

each ring slid fully into place one at a time, without disturbing the butted ends

butted ends staggered 120 deg

run-in time before full adjustment

***packing material, esp graphite & Teflon products, does not relax after tightening. It's important not to over tighten at any stage

initially tighten finger-tight only, then:

put in the water, tighten only as needed to keep flow to a dribble

tie off, start engine and run at idle in gear, tighten only as above, allow to run this way for a short while, adjust only as above when needed

take the boat out with an assistant operating, over a half hour's time increase speed in increments, allow time to settle-in, adjust as above.

once up to normal cruising speed, adjust for a slight dribble. Run the boat this way the next few operating hours, then adjust at cruising speed for a steady stream of drops. As long as the temperature remains fine you can then adjust down to as little as 3 drops per second at cruising speed for a small shaft.

It seems like a lot of fuss, but this should then last 1500 hours or more and require just a very slight adjustment about every 250 hours.

My 1-1/4" shaft causes a bilge pump cycle about once every two weeks at rest and about 10 hours at cruising speed. The nut stays cool enough to grip your bare hand on at any speed

[Wotname]

Originally Posted by EngNate

........... As long as the temperature remains fine you can then adjust down to as little as 3 drops per second at cruising speed for a small shaft.
.............

Is this a typo?

[Pete the Cat]

Originally Posted by EngNate

Several things important:

Clean tube & nut and smooth shaft surface

Correct packing size - tube dia minus shaft dia / 2

Rings cut so the ends butt together well- no gap & no excess

lubricant as recommended by the material maker - outside and inside the circle

each ring slid fully into place one at a time, without disturbing the butted ends

butted ends staggered 120 deg

run-in time before full adjustment

***packing material, esp graphite & Teflon products, does not relax after tightening. It's important not to over tighten at any stage

initially tighten finger-tight only, then:

put in the water, tighten only as needed to keep flow to a dribble

tie off, start engine and run at idle in gear, tighten only as above, allow to run this way for a short while, adjust only as above when needed

take the boat out with an assistant operating, over a half hour's time increase speed in increments, allow time to settle-in, adjust as above.

once up to normal cruising speed, adjust for a slight dribble. Run the boat this way the next few operating hours, then adjust at cruising speed for a steady stream of drops. As long as the temperature remains fine you can then adjust down to as little as 3 drops per second at cruising speed for a small shaft.

It seems like a lot of fuss, but this should then last 1500 hours or more and require just a very slight adjustment about every 250 hours.

My 1-1/4" shaft causes a bilge pump cycle about once every two weeks at rest and about 10 hours at cruising speed. The nut stays cool enough to grip your bare hand on at any speed

Exactly my experience. Hand tighten first. Go slow with tightening and you can have a dry or nearly dry bilge. Have done this for more than 20 years.

[HappyGuy]

RaymondR Never - never use Graphite packing in a stern gland.

It works well on industrial plant but causes problems with stern glands.

The reason being electrolysis will eat holes in the stainless steel shaft because Graphite it is conductive.
Use only greasy hemp, cotton or Teflon packing.

The joins in the rings of packing should be spaced 120 degrees apart.
If they are in line you will never stop the gland leaking.

After re-packing tighten the gland nut then back off a bit. Run the prop shaft in gear and tighten sufficiently so you only get a drip or two every second.

The gland should never run more than luke-warm,
If it runs hot then you have the gland nut too tight.

You will need to tighten the gland a few times every few hours until the packing "beds in"

This type of gland should always drip one or two drops a second when adjusted correctly otherwise there is a risk of overheating. If it overheats too much it could mean having to fit a new shaft as the shaft will likely be scored.

When motor is shut down give the stern greaser a turn and this should stop the glad leaking while anchored/moored.

If you want a stern gland that does not leak you will need to go to the expense of fitting a mechanical seal.

[Rosi]

Metric maybe ?

[EngNate]

Yes, 3 drops per second - .5L per hour. Half that, perhaps, but if it gets starved for water (lubrication) under any conditions it will cost in service life.

Here's some info on the graphite question:
https://www.onepetro.org/conference-paper/NACE-00639

And handy charts on galvanic compatibility:
Galvanic Series (electrochemical series)

[rbk]

Originally Posted by EngNate

Yes, 3 drops per second - .5L per hour. Half that, perhaps, but if it gets starved for water (lubrication) under any conditions it will cost in service life.

Here's some info on the graphite question:
https://www.onepetro.org/conference-paper/NACE-00639

And handy charts on galvanic compatibility:
Galvanic Series (electrochemical series)

As noted there’s technically nothing wrong with running a higher drip rate (cooler, longer service life vs wet bilge, potential water spray) but most packing gland material can run @ that rate per/min without issue.

[Wotname]

Originally Posted by EngNate

Yes, 3 drops per second - .5L per hour. Half that, perhaps, but if it gets starved for water (lubrication) under any conditions it will cost in service life.
............

OK, thanks for your answer.

[OldManMirage]

Originally Posted by Ryban

So I slept on it to avoid making any rash decisions and tackled it again this morning, and I have good news to report -- the problem is resolved! (for now)

After reading the helpful posts here, and talking to a few people around the boatyard, I decided to remove the 1/4" packing (for the second time), and switch the 3/16". To make the 3/16" fit better, I did gently flatten it with a hammer before cutting the rings to size.

After one ring, the shaft seal leaked quite a bit. After two rings, it leaked a lot less. After three rings, I was able to fine-tune the dripping, and the packing nut only gets warm.

I will leave it like this for the time being, but I suspect I have room for 1 or 2 more rings in there.

Glad you got it sorted Ryban/Tarka !

Love the videos by the way. Be sure to look for that elusive Baby Taylor. Or you could try switching to a Ukulele. You can fit those anywhere.

Or you could try a Cordoba Mini. I'm not a big fan of the nylon string sound, but it is a guitar with a reasonable size fretboard. They come with strings in the key of A, but you can get a set in E. It actually sounds better in A. And its hardly bigger than a uke. Its too bad you're so far away or we could make a deal for this one ! LOL

[Pete the Cat]

Originally Posted by HappyGuy

RaymondR Never - never use Graphite packing in a stern gland.

It works well on industrial plant but causes problems with stern glands.

The reason being electrolysis will eat holes in the stainless steel shaft because Graphite it is conductive.
Use only greasy hemp, cotton or Teflon packing.

The joins in the rings of packing should be spaced 120 degrees apart.
If they are in line you will never stop the gland leaking.

After re-packing tighten the gland nut then back off a bit. Run the prop shaft in gear and tighten sufficiently so you only get a drip or two every second.

The gland should never run more than luke-warm,
If it runs hot then you have the gland nut too tight.

You will need to tighten the gland a few times every few hours until the packing "beds in"

This type of gland should always drip one or two drops a second when adjusted correctly otherwise there is a risk of overheating. If it overheats too much it could mean having to fit a new shaft as the shaft will likely be scored.

When motor is shut down give the stern greaser a turn and this should stop the glad leaking while anchored/moored.

If you want a stern gland that does not leak you will need to go to the expense of fitting a mechanical seal.

I have been using graphite on an Auquamet shaft for more than 20 years with no scoring , no corrosion and no drips. Many miles and hours of motoring for years of cruising through Central America. Installation must be done carefully so as to not overtighten. The lobster folks here in Maine have been using this stuff for longer than that for thousands of hours, every day (except Sunday-no lobstering on Sunday). The US Navy uses this stuff on nuclear subs—you don’t have a drip or bellows at a thousand fathoms and they go kinda fast.
I am a former delivery skipper who has a low opinion and very bad experience with mechanical dripless systems. If the bellows leaks you are going to the yard (if you are lucky). Had to make an emergency detour and haul for a bellows leak. Mechanical dripless are, IMHO, a hazard if you go offshore. There might be some electrical conductivity in graphite, but the whole thing is isolated by a rubber tube. I have replaced the graphite packing a couple times, but it never appeared to need it, nor did was there any scoring or corrosion. Packed with Syntef grease if that makes any difference.

[ferrailleur]

Originally Posted by Ryban

I took the shaft out entirely, because I also wanted to replace the hose connecting the stuffing box to the stern tube. Thus, I had full and easy access to the inside of the stuffing box, and cleaned it out very well. Nothing was left inside.

I'm using PTFE Flax with Teflon, but now that I look closely at the fine print on the package, it does say I should be using a "Syntef"shaft packing lubricant when installing new packing -- which I did not do.

Again regarding the drips: I get no drips from where the shaft enters the packing nut. The only drips I get are between the threads of the male and female portions of the packing box -- which I can make go away with a few easy turns.

In any case, I'll be making a trip to the marine store this morning and will pick up some more packing, and I guess lubricant, and give this another go. I'll record the whole thing, too, so you lot can point out all my mistakes .

did you use the Syntel shaft lubricant? I thought the PTFE fax was all I needed.

[bcguy]

'This high performance non-graphite packing, SynBraid®, is a 100% galvanically inert synthetic high performance packing, not a “PTFE infused” product with acrylic or flax yarns making up the braid. The SynBraid® yarns are actually extruded with the proprietary lubricant in the yarn not “infused” after the yarns are extruded. I expect SynBraid® to be on the market sometime in early 2018" Anyone using SynBraid? Results and where to buy ... thanks

[Bear15]

I know this thread goes back to last year and I had commented with the same problem, everything was solved this year by changing to the PSS dripless, no more problems.