RePack or Dripless Shaft Seals?

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
jungpeter said:
Well, I'm far from an "expert", but here's my experience with exactly your conundrum.



My previous boat had 2" shafts, with conventional packing glands. It was easy-peasy to back off the packing nuts, twist out the old packing (using a purpose-made packing removal tool), and re-pack. Not positive of the exact product I used, but believe it was GTU Graftex Ultra-Shaft packing from Western Pacific Trading, which allows almost a leak-tight seal, both underway and at rest. All this while in the water.



Yup, water floods the boat while you work. Not as much as you'd think, and easily controllable with your bilge pump, assuming it's properly sized and working. Make sure you have the correct packing on hand before you start. Pre-cut the new packing to size before you begin, so you are ready to install ASAP the old stuff is reefed out. And have all your tools close at hand also.



If you haven't done this before, you may want to get a boatwright to do the first one while you watch, to glean any tricks of the trade I haven't mentioned. It should take about one hour per shaft, so you'd invest whatever the boatwright charged, but might be cheap insurance for your peace of mind.



My current boat has a PYI dripless seal on a single shaft, as well as the rudder post. No leaking on the driveshaft to date, but basically unserviceable in the water, either. My rudder shaft is leaking, and will have to wait for my next haulout to remove and R&R.



In my opinion, I would not replace conventional packing glands with dripless. They cost far more than they're worth.



Regards,



Pete
Click to expand...


Just a heads up on your leaking PYI drip less seal. Talk with PYI, don't assume. I had my PYI drip less seal leaking and was told to take some wet/dry 600 grit sand paper, cut into 4"x4" square, fold in half, pull open the seal surface towards the bellows, insert the folded sand paper and drag it around the seal surface two or three times in one direction. This cleans off the contaminants that are causing the drips.
 
the amount of water flow will depend on the gap between the shaft and the stuffing box itself without packing. In my case with 3" shafts flow was minimal. I kept a rag tied around the shaft to push into the gap temporarily if needed. Having the rings pre cut helps because you can stuff the first on in quickly and most of the water flow will be stopped. I never experienced any time when I was dependent on pumps to keep the boat afloat. I really like the idea of a pre cut piece of PVC pipe to settle the rings evenly but you will have to have the right size shafts and box. I just pushed the rings in with fingers then tightened down the box lightly to seat the ring. Clearing off the box threads with water and wire brush before disassembly makes things go easier. A good soaking with WD 40 helps as well.


Getting out the old rings took the most time. The corkscrew tool and dental pics did the job. Scrape the pic along the empty box to make sure there are no small pieces of packing left. T
 
Last edited:
Capt.Bill11 said:
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.
Click to expand...
Good point. This is a freaky scary job for some the first time so that's why I suggested putting the pump(s) to the test before opening the spillway gates.
 
Capt.Bill11 said:
Has your dog ever heard of a bore scope? Compression test? Leak down test? Or fluid analysis?
Click to expand...

Wow, these are the tests you run on your vehicles after every time you use them? I guess if you think this is necessary that's fine but it seems way overkill to me. Unless, of course, you buy totally crap vehicles in which case perhaps it's necessary. But my reality is that I've never owned a vehicle yet that had its engine fail, even after close to 300,000 miles on a couple of them And all I ever do is change the oil and filters regularly. Water pumps crap out from time to time, and other ancillary stuff conks out occasionally but the engines juat go and go even without the plethora of tests you apparently run all the time. But perhaps I'm just not paranoid enough.:)


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.
Click to expand...


A) My dog is WAY too smart to want anything to do with Florida, which he doesn't even consider part of the US and B) I mention the Travelift size merely as a way of pointing out that this particular yard caters to much more than the typical toy boat crowd but serves people whose livlihood depends on their vessels operating correctly and reliably. If they weren't very good at what they do the commercial boat folks wouldn't use them.
 
Last edited:
This might be fun to watch...
 

Attachments

  • Pissing Contest.jpg
    Pissing Contest.jpg
    71.1 KB · Views: 393
Alaskan Sea-Duction said:
What say the TF experts?:confused:
Click to expand...

I assume you will be hauling your vessel for various tasks prior to taking off for the PNW? If so, other than adding a few rings at this time -if needed- maybe wait until haul out time so a thorough 100% safe job can be done?
 
sunchaser said:
I assume you will be hauling your vessel for various tasks prior to taking off for the PNW? If so, other than adding a few rings at this time -if needed- maybe wait until haul out time so a thorough 100% safe job can be done?
Click to expand...
Naw, everyone needs to put their pacemaker to the test by doing it in the water at least once.:)
 
Hawgwash said:
This might be fun to watch...
Click to expand...

This is why, Hawg, I put zero stock in what people on amateur forums such as this one recommend or claim is th "right way" to do somethng. Because for every "expert " opinion there will always be someone claiming that their totally opposite opinion is the "correct" way.

Forums like this are highly entertaining which is why I play on it but as far as getting information you can truly bank on, with the very few and far between experts like Peggie Hall and Rick Boggs, an amateur-hour forum like this is not something I use to get actual correct answers to questions I might have. We have built up a whole bank of truly knowledgeable and experienced resources in this area we use for that.

And now I'm going to go off here in Toronto to talk to Air Canada about a 777.
 
Marin said:
Wow, these are the tests you run on your vehicles after every time you use them? I guess if you think this is necessary that's fine but it seems way overkill to me. Unless, of course, you buy totally crap vehicles in which case perhaps it's necessary. But my reality is that I've never owned a vehicle yet that had its engine fail, even after close to 300,000 miles on a couple of them And all I ever do is change the oil and filters regularly. Water pumps crap out from time to time, and other ancillary stuff conks out occasionally but the engines juat go and go even without the plethora of tests you apparently run all the time. But perhaps I'm just not paranoid enough.:)





A) My dog is WAY too smart to want anything to do with Florida, which he doesn't even consider part of the US and B) I mention the Travelift size merely as a way of pointing out that this particular yard caters to much more than the typical toy boat crowd but serves people whose livlihood depends on their vessels operating correctly and reliably. If they weren't very good at what they do the commercial boat folks wouldn't use them.
Click to expand...

Yeah, that's it, I own crap vehicles and live in a state with lots of transplanted foreigners in it. Sorry if that last fact makes you and your dog uncomfortable.

So what's next? Your going to say something bad about my mother? :lol::lol::lol:

And if you think just because a yard caters to commercial fishing boats that means they do top notch work, you need to get out more.

But you still haven't answered the question. Is it just GFO packing they are seeing people over tightening? Or are people over tightening flax as well?
 
Marin said:
This is why, Hawg, I put zero stock in what people on amateur forums such as this one recommend or claim is th "right way" to do somethng. Because for every "expert " opinion there will always be someone claiming that their totally opposite opinion is the "correct" way.

Forums like this are highly entertaining which is why I play on it but as far as getting information you can truly bank on, with the very few and far between experts like Peggie Hall and Rick Boggs, an amateur-hour forum like this is not something I use to get actual correct answers to questions I might have. We have built up a whole bank of truly knowledgeable and experienced resources in this area we use for that.

And now I'm going to go off here in Toronto to talk to Air Canada about a 777.
Click to expand...


What does that say about your 13,000 posts here???
 
Thanks all for your suggestions and comments.
 
sunchaser said:
I assume you will be hauling your vessel for various tasks prior to taking off for the PNW? If so, other than adding a few rings at this time -if needed- maybe wait until haul out time so a thorough 100% safe job can be done?
Click to expand...

Good point. I was planning a haulout in November. I will use Astoria as Englund marine is right around the corner.....


Then it is a 6 hour run back to the dock. enough time to adjust and break in the new seal.....
 
Alaskan Sea-Duction said:
I was planning a haulout in November. Then it is a 6 hour run back to the dock. enough time to adjust and break in the new seal.....
Click to expand...
Well there you go.
Just get them to let you watch the repack.
 
"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".

IT Flew In didn't it?

USN Ferry Pilot song,
 
Capt.Bill11 said:
Is it just GFO packing they are seeing people over tightening? Or are people over tightening flax as well?
Click to expand...

They didn't differentiate between the kinds of people doing the wrong thing. They simply said that when Gore/synthetics are overtightened to the point of running too hot they tend to become brittle and crack. Flax, they said, doesn't do this.

They are NOT saying that this is an excuse to overtighten flax, only that when someone adjusts the nuts incorrectly or fails to monitor or check the packng glands in their boat and they are running too hot, Gore/synthetics are prone to damage and potential failure under conditions that flax will stand up to. And they say they have seen the problems with Gore/synthetics enough to not recommend its use although they will install it if an owner desires.

They do, however, like Gore/synthetics for packing rudder shafts.
 
Marin said:
They are NOT saying that this is an excuse to overtighten flax, only that when someone adjusts the nuts incorrectly or fails to monitor or check the packng glands in their boat and they are running too hot, Gore/synthetics are prone to damage and potential failure under conditions that flax will stand up to.
Click to expand...


Sorry I'm not buying it. GFO has a lower coefficient of friction than flax. Flax needs water flowing around it to cool it in most cases. GFO can be run dripless. If you get flax packing hot the "wax" in it melts right out and the fiction heat climbs way up. I've even seen misadjusted boxes packed with flax start smoking from the friction.

But whatever. People can make their own choice on what to use.
 
Marin said:
They didn't differentiate between the kinds of people doing the wrong thing. They simply said that when Gore/synthetics are overtightened to the point of running too hot they tend to become brittle and crack. Flax, they said, doesn't do this.

They are NOT saying that this is an excuse to overtighten flax, only that when someone adjusts the nuts incorrectly or fails to monitor or check the packng glands in their boat and they are running too hot, Gore/synthetics are prone to damage and potential failure under conditions that flax will stand up to. And they say they have seen the problems with Gore/synthetics enough to not recommend its use although they will install it if an owner desires.
Click to expand...

I find this to be an absolutely amazing claim. I am positive that they have confused GFO with something else entirely.

I am sure that the W.L Gore Company technical reps would be all over this if given an opportunity.

Something is fundamentally wrong.

I still maintain that a small drip is required while running.
 
Northern Spy said:
I
I am sure that the W.L Gore Company technical reps would be all over this if given an opportunity.
Click to expand...

I wouldn't know. We don't warranty our airplanes against someone negligently or deliberately flying them into a mountain. Perhaps Gore doesn't concern themselves with people who use their products incorrectly.
 
Northern Spy said:
I find this to be an absolutely amazing claim. I am positive that they have confused GFO with something else entirely.

I am sure that the W.L Gore Company technical reps would be all over this if given an opportunity.

Something is fundamentally wrong.

I still maintain that a small drip is required while running.
Click to expand...

I installed the GTU brand from Defender in pressure cooled stuffing boxes last spring. Set them for a slight drip after splashing the boat. Took off on a 11 hour jaunt over to Michigan the next morning. Per the plan I whipped out my $27 Harbor Freight temp detector about ten minutes up the channel at hull speed. Starboard stuffing box was running at about 70 degrees F (water temp was 42). Port side was at 185! Holy crap. Long story short, the port for the cooling hose barb at the heat exchanger was clogged. Fixed it enroute (temp dropped to 70 degrees) and checked the first ring at destination. No obvious issues...no lube stuff dripping from the ring. No leaks sitting in the slip. Nice stuff(ing)., but I wonder how hot it would have gotten at high rpm....

Checking for flow at the stuffing boxes is now on my Spring checklist....and I must remove and descale those heat exchangers.
 
Last edited:
"I still maintain that a small drip is required while running."

Nope , not any more .

The huge advantage to no dripping is silt and sand are not carried into the packing where it will embed and score the shaft.

The good news is the modern stuff will seal an old scored shaft .Harder flax or tefflon usually will not.
 
I had to goggle up the Gore GFO web site to see what they recommend for installing the packing. I have re-packed pump shafts and propeller shafts up to 36" dia., 2 HP up to 50,000 shaft HP. Sure enough you can cut the GFO rings on the pump/propeller shaft or use a mandrel, and they say you will have virtually no leak off. After all GFO is Teflon impregnated with graphite, I may even think to use it one day after the Teflon I used eight years ago to pack my propeller shaft wears out, but I think it will last longer than I will.
 
FF said:
"I still maintain that a small drip is required while running."

Nope , not any more .
Click to expand...

But...doesn't there need to be a supply of fresh oxygenated water (albeit very small) to inhibit corrosion of the stainless steel shaft?
 
to inhibit corrosion of the stainless steel shaft?

I have seen SS bolts 1/2 or more gone , but never a shaft.
 
HiDHo said:
I had to goggle up the Gore GFO web site...Sure enough you can cut the GFO rings on the pump/propeller shaft...
Click to expand...
I didn't say you couldn't use the shaft as a cutting board, I said I wouldn't recommend it.

You, me and a dozen others on here could get away with it but someone could come here for the first time, looking for a how to, read it's ok to use the shaft as an anvil and go at the packing with a hacksaw or chisel.

A two story pump or turbine room where you have your 86 drawer tool chest at your elbow is different from a cramped engine room where people should not be encouraged to improvise.
 
I cut rings in my shaft, but I have a long shaft. I just don't do it near the sealing area or steady bearing area.

Gore is the same material as "Teflon", but expanded as it is made. Hence ePTFE, instead of PTFE. PTFE yarn and ePTFE yarn are very different. The method of making Gore was the differentiation of the patent, which gave them a monopoly for years. People mix it up all the time, from supply chain to the tradesperson. I bet I field a dozen questions a week on gaskets and packing at work, much due to interchange if materials.

And as far as the drip goes, I still maintain you need it. Cooling and pitting. I have detected pitting corrosion on all sorts of various alloys in chloride solution services. I'd prefer not to rework my shaft. Weld metal build up and machining, or sleeving of shafts is expensive, time consuming, and may compromise the integrity of the shaft, if not done properly. I've had many weekends ruined because of repairs not done properly and leaving a teeny tiny stress riser in the shaft repair surface.
 
Last edited:
Hawgwash said:
I didn't say you couldn't use the shaft as a cutting board, I said I wouldn't recommend it.

You, me and a dozen others on here could get away with it but someone could come here for the first time, looking for a how to, read it's ok to use the shaft as an anvil and go at the packing with a hacksaw or chisel.

A two story pump or turbine room where you have your 86 drawer tool chest at your elbow is different from a cramped engine room where people should not be encouraged to improvise.
Click to expand...

I see you logic but GFO cuts like butter with a razor blade. Much neasier that flax. And your are cutting it up on the shaft far from where it would be in the box not where it will end up riding on the shaft. So you really can't do any damage to the shaft.
 
You must log in or register to reply here.

Similar threads

E
Shaft seal leak!!!
Replies
25
Views
3K
mvweebles
mvweebles
M
Shaft Packing
Replies
17
Views
1K
C lectric
C lectric
P
stuffing box on a marine trader
Replies
18
Views
2K
Comodave
Comodave
captmikem
Replacing a dripless shaft seal in the water.
Replies
7
Views
1K
sunchaser
S
Barking Sands
Drive Saver shaft coupling questions
Replies
24
Views
2K
Steve DAntonio
Steve DAntonio

Latest posts

Back
Top Bottom