RePack or Dripless Shaft Seals?

Can someone recommend a mechanic in the Portland OR area that would be willing to come out to the boat?

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I've not had any direct experience with these folks but you might contact Schooner Creek. I've heard good words about them and they seem to have a good boatyard. Just a suggestion.

Stan

Something I found when I re packed mine, somebody had used a graphite-impregnated stuffing, which is fine in theory but checkout where carbon sits on the electrolysis scale. My stuffing box metal was deteriorating and I caught it just in time. YMMV

The yard in our harbor recommends flax for standard packing glands. They will install the Gore and other "synthetic" materials if an owner requests them but they don't recommend them. The reason is that if the packing gland overheats the synthetics turn into "plastic," become brittle, and break.

Now if one is conscientious about monitoring the adjustment and temperature of the packing gland(s), no problem. But apparently most boaters don't do this, and the yard has made a fair amount of money replacing synthetic packing material that has overheated and failed.

As to how long packing lasts, I have no idea. But the flax in our packing glands has gone some 12 or 13 years with no problems. By which I mean no dripping underway or at rest and the packing glands run dead cold. And the owner of a sailboat in our club (former chief engineer at Uniflite) has had the flax packing in his boat for more than a couple of decades with no issues to date.

The melting point of PTFE is 620F.

That is why frying pans are coated with it.

We did ours in the water and the sound of an ocean trying to rush into our boat was very disconcerting

Before starting we tore strips of cloth and cut a bicycle inner tube into strips as well. Once opened up and the water started flowing, cloth strips were tied tight around the shaft and jammed to stop the water flowing in, then the rubber inner tube strips were tied over the cloth strips to keep them in place.

Once this was done the job went at a smooth, relaxed pace.

Drip less packing systems CAN leak, check out the videos on u tube

https://youtu.be/GXbG9Ws5HqE

The bellows can leak too, possible salvage liability if bad. Any repairs and installation require haul out.

You can get traditional packing anywhere, PSS parts could delay your cruise and cost $$. Easy choice IMO.

Duramax is good stuff. Been in my sporty for about 5 years, no problems, no leaks. Got kinda hot during the first hour of operation but some adjustments fixed that. It was a little tight. Marin, how did that "chief engineer for uniflite" job work out for your friend ?

Be sure to leave the packing nut loose and leaking until it has been run in. Even with the goretex or teflon. You should be able to do the initial run at idle in the slip. Then tighten down in steps. Its too easy to overtighten initially which causes overheat and shaft scoring.

Its probably better to have someone , with experience observe the first time you do it there.

You will need the corkscrew puller if there is much depth to the stuffing box, $10-$15 at worst marine.

You wrap a stuffing material a turn around the shaft and use a razor to cut each ring with the ends being at a 30 or 45 deg angle, just not square.

Purchase a foot or so of plastic pipe with the inside diameter the same as your shaft size.

Cut it in half the long way with a jig saw or hand hacksaw.

The drill is to pull of the end nut and use a SS toothbrush to clean what threads you can see.

Cut as many rings as you will need or MORE so there is no fumbling.

Pull the packing out and when you get the last one there will be a nice inrush of water.

Wrap a pre cut ring and put it in the space and then use the 2 parts of the plastic tubing to push it square as far as it will go.

Keep doing that with the cut ends NOT in line until the space is packed.

Sometimes the first ring , sometimes the second will hold back the water so it is dripping but not rushing into the boat.

Reinstall the end compressor nut or fitting and you want it snug but not tight.

When you are done there will be no dripping.Start the engine and adjust as the shaft spins.

At the first outing the nut may need to be tightened as the material conforms to the spinning shaft.

Again , just stop the drip underway.

Underway the fitting will be barely warm if at all when tightened properly.

After a month check there are no drips .

Enjoy

Good, easy to follow how to, FF.
Only thing I would add is if the chaser/follower is held in place by two or more nuts, they be tightened alternately on opposite sides like wheel nuts.
And the handy tools.

You can also use dental pics to pull old stuffing. Available at Harbor freight and other tool stores.

Be careful who you select to do the work. There are several good yards in the Portland area experienced at doing this work. I would follow Spy's advice and put in a few rings now. Then on the next haul out have it all removed, inspect everything carefully without a flood and repack with the right stuff.

sunchaser said:

Be careful who you select to do the work. There are several good yards in the Portland area experienced at doing this work. I would follow Spy's advice and put in a few rings now. Then on the next haul out have it all removed, inspect everything carefully without a flood and repack with the right stuff.

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We did it in the yard the first time, having never done it before. The second time was in the water. I was amazed at how little things had to be tightened to stop the water...makes me wonder how many people over tighten the packing nuts when it's done on the hard.

As an aside, I talked to one fellow who thought he was supposed to tighten it a bit every time he took his boat out, so I suggested he might want to do a little research about that

MurrayM said:

I was amazed at how little things had to be tightened to stop the water...makes me wonder how many people over tighten the packing nuts when it's done on the hard.

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This is one of those boat systems that people either forget about or over think. Water pouring in and fire scare the bejayzus out of boaters but this one is really simple.

Not too tight and just keep a eye on it as part of your boating routine.

So with 2 1/4 inch shafts what size to material do I buy? Thanks for all the help....

Greetings,
Mr. ASD. The shaft size has nothing to do with the size of the packing other than the overall length of the material needed. Number of rows/layers of packing times the circumference. The critical measurement is the space between the shaft and the inside of the stuffing box. As mentioned, take a regular drill bit and try to slide the non-business end into the space between the shaft and stuffing box. Buy your stuffing material based on this measurement but buy a bit undersized if necessary. Meaning if your space is 5/16" buy 1/4" packing, NOT 3/8" (you'll never get 3/8" into the annular space but the 1/4" will deform on tightening and fill any voids).

Compass Marine has a good video on re packing a traditional gland.

RT Firefly said:

Greetings,
Mr. ASD. The shaft size has nothing to do with the size of the packing other than the overall length of the material needed.

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Well, it kind of does. One of the critical ratings for packing is speed of the shaft. Let's assume a 3000rpm diesel, 2:1 reduction and a 2.5 inch shaft. A 2.5 inch shaft at 1500 rpm has a surface speed of 982 feet per minute. Pretty slow actually, about 11 mph.

So in absolute terms, it doesn't matter too much as flax traditionally is rated at 1000 to 12000 fpm, whereas PTFE and ePTFE is usually around 4000 fpm.

But these ratings are for well adjusted, and well lubricated packing. The flax doesn't allow for as much margin at higher speeds particularly if it is over tightened, which is often the case on many boats I've seen.

Northern Spy said:

But these ratings are for well adjusted, and well lubricated packing. The flax doesn't allow for as much margin at higher speeds particularly if it is over tightened, which is often the case on many boats I've seen.

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Spy, this is a good debate and though maybe a little too technical at times, hopefully it makes people aware of an otherwise ignored system. Ignored mostly because it is out of sight and people don't understand the purpose or mechanics of it.

Now, help me with the new materials because I still believe in a drip, even if only one or two a minute, under way, for lubricating as much as cooling.

Marin; said:

But the flax in our packing glands has gone some 12 or 13 years with no problems. By which I mean no dripping underway or at rest and the packing glands run dead cold.

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Am I behind the technology?

Hawgwash said:

Spy, this is a good debate and though maybe a little too technical at times, hopefully it makes people aware of an otherwise ignored system. Ignored mostly because it is out of sight and people don't understand the purpose or mechanics of it.

Now, help me with the new materials because I still believe in a drip, even if only one or two a minute, under way, for lubricating as much as cooling.

Am I behind the technology?

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Old school flax packing normally will run warm to hot if you try to run it dripless. Unless you only run you boat a slow speeds.

Marin apparently pulls all his packing out at least once a year, looks at it and reinstalls it. Otherwise I have no idea how he would know it's true condition after 13 years of use.

As to GFO turning to "plastic" due to the box running hot, well if they say so. But I can't imagine how over tight you'd have to get the box to do that. And if true, it's probably better it happened with GFO. Because if you over tightened a box like that with plain packing in it I'd think you'd start a fire in the box.

I mean GFO is rated to 500-600 degrees or there about.

And they see this problem a lot !? Do they see a lot of burnt up flax packing as well? Or is it only people using GFO that some how manage to keep over tightening their boxes?

RT Firefly said:

Greetings,
Mr. ASD. The shaft size has nothing to do with the size of the packing other than the overall length of the material needed. Number of rows/layers of packing times the circumference. The critical measurement is the space between the shaft and the inside of the stuffing box. As mentioned, take a regular drill bit and try to slide the non-business end into the space between the shaft and stuffing box. Buy your stuffing material based on this measurement but buy a bit undersized if necessary. Meaning if your space is 5/16" buy 1/4" packing, NOT 3/8" (you'll never get 3/8" into the annular space but the 1/4" will deform on tightening and fill any voids).

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Thanks RT. I now understand the drill bit part. Thanks for explaining....

Alaskan Sea-Duction said:

So with 2 1/4 inch shafts what size to material do I buy? Thanks for all the help....

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The Buck-Algonquin catalog has different type stuffing boxes for 2 1/4" shafts. Depending on the type, they use 3/8, 7/16, or 1/2" packing so measuring is the most definite way.

High Wire said:

Depending on the type, they use 3/8, 7/16, or 1/2" packing so measuring is the most definite way.

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Yup.
If all else fails, pop a ring out of the good gland, measure it and stick it back in.

Use the shaft as a mandrel to cut the new packing. Don't butt cut the packing rings, cut the joints on a bias and as mentioned before stagger the rings joints. Packing pullers can be bought in different sizes, a good alternative is a welding rod. Heat the tip on a grinding wheel and bend into a hook and quench in cold water to temper the hook. Seat the new rings in the gland then back off slightly to get a steady drip, adjust as required BUT never wear loose clothes near a turning propeller shaft, safer to make minor adjustments after the engine is secured.

HiDHo said:

Use the shaft as a mandrel to cut the new packing.

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I wouldn't recommend using the shaft as a mandrel for cutting.
A measuring tool, sure; wrap 3 or 4 turns tightly around the shaft, scribe each with a razor blade and remove it for cutting.

Capt.Bill11 said:

Marin apparently pulls all his packing out at least once a year, looks at it and reinstalls it. Otherwise I have no idea how he would know it's true condition after 13 years of use.

As to GFO turning to "plastic" due to the box running hot, well if they say so. Or is it only people using GFO that some how manage to keep over tightening their boxes?

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If the packing gland is not dripping or is just barely dripping and the gland and log are running dead cold it's a pretty fair bet the packing is in good shape. I don't have to pull the pistons every year on a perfectly running engine to know that they're in good shape, either. Even my dog understands this fairly rudimentary logic.

But for those who cannot make the connection between a piece of equipment that's operating correctly and the internal condition of that piece of equipment, we just had the packing in our PNW boat changed the other week, so that's how we know what shape it was in after all those years. It didn't really need changing but as the yard was doing work there anyway we hed them change it.

Apparently they see a sufficient number of problems with Gore and other types of "synthetic" packing to not recommend them although they will install them if an owner requests it. This is not a toy boat boatyard, by the way. With 35 and 165 ton Travelifts (I had thought it was 150 tons but just learned it's 165) at least half their work is large yachts and commercial fishing and crabbing boats with recreational power and sail boats, wood, glass and metal, making up the rest. So they've had a wee bit of experience with this sort of thing.

Northern Spy said:

If the adjustment is just about bottomed out, why not just add another ring and snug back up? Approximately 70% of the sealing comes from the two rings closest to the gland follower anyways. The bottom rings are more or less spacers as they see very little compression.

Use a square braided yarn made of GFO or ePTFE.

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Also Capt Bill and Hawgwash give great advice.

I just put more material in.
Also, I did have someone show me the first time and that really helped.

Not trying to pull out the old material, keeps the water inflow to a fast trickle.

Good luck.

One difference might be some of the larger commercials use the flax packing as the tail shaft packing asb a bearing bearing.

Our 90/90 is small but we obtained a unit that has 18 turns of packing , and no cutlass rubber bearing.

This was required as our large 2 blade prop wants to move as it is covered and uncovered from the deadwood.

The high blade loading on many bigger boats might be similar.

The GFO does work for us .

The drill with the old packing was grease cup under the galley sink that required a turn after operating to seal the required cooling drip.

Marin said:

If the packing gland is not dripping or is just barely dripping and the gland and log are running dead cold it's a pretty fair bet the packing is in good shape. I don't have to pull the pistons every year on a perfectly running engine to know that they're in good shape, either. Even my dog understands this fairly rudimentary logic.

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Has your dog ever heard of a bore scope? Compression test? Leak down test? Or fluid analysis?

Or does his rudimentary logic just end at, "Well it ran fine yesterday, so I don't see why we need to monitor it's condition? Let's just run it till it fails catastrophically".


If your dog is judging the quality of a boatyard by the size of their lift, I guess he needs to start bringing your boat to S FL.

Changing your packing while your boat is in the water makes for a good controlled test for your bilge pump system. If your pump/s can't more than handle the flow of one or two open stuffing boxes, you need some more and/or bigger pumps.