Stuffing Box Hell

tenders

Innocent Bystander
My concern with the PVC bushing would be that the bond with epoxy could fail over time due to shaft vibration and the differences in expansion rates due to temperature fluctuations. This may not be a valid concern, however; I’ve never epoxied any PVC that was important. You might consider using West GFlex epoxy, and giving them a call to confirm/consult before proceeding.

On the Dremel: they make Dremel with a head extension that lets you pull the spinning bits quite far away from the motor, so it can get into small places. Not sure Harbor Freight units have this feature.

You know you can mount the blades on the oscillating tool at 90° to the tool, right? That doesn’t let you get in close enough to clear the fiberglass bog out?
 

wynkoop

Member III
Tenders this AM I woke up with visions of failed epoxy and the bushing both spinning and allowing sea water to pass, and said to myself what were you thinking!

The sanding head on the oscillating tool is a 60 degree triangle, so turning the head is of no moment really, and the pads do not last well on the glass mess.

With a saw blade there is no position I can put the blade in that will allow me to cut parallel to the hull and even if I could I would be worried about cutting past the bottom of the V and going through the other side of the hull.

This is the job for a small grinder I fear. Not sure on extensions for the harbor freight tool, but I expect any dremmel accessory would fit the harbor freight tool. That has been my experience with other HF tools.

Hope like hell I do not have to try and clean up the old stuffing box while waiting on hose from the UK.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Regarding grinding in tight spaces...
When there were pretty good holiday price mark down's on Dremel tool kits in December, I bought one from Lowe's, IIRC.
First time with the "real thing" after about 20 years of using low-torque knock-offs from Harbor Freight.
Big Difference.:D
The zippered 'soft'case contains a flexible extension, too.
While the Harbor Freight version is inexpensive, you lose considerable functionality. "No free lunch" as the old saying goes.
 

tenders

Innocent Bystander
Yeah, I would agree, I think of most Harbor Freight stuff as being tool auditions. The Dremel has long proven itself to be such an indispensible tool for boat situations that I have conferred Brand Name Status to it in my toolkit. And the Full Monte version, for sure - not the battery-powered one.

(For whatever reason I haven't minded the noisy, buzzy, $20 Harbor Freight oscillating saw, although its utility is worthy of Brand Name Status.)

The flexible extension thing I think would be useful to you and your Dremel/equivalent for this situation is something like this:
 

wynkoop

Member III
I actually own a real dremmel, but it is 300 miles away and requires a few days travel to get it and bring it back. Kicking myself because I had it here for a long while and took it to my mountain place last trip a few weeks ago.

Thinking I will slip a piece of PVC pipe over the stern tube to protect it while I grind.
 

wynkoop

Member III
For a guy who went to school to be a Deck Officer I sure seem to be spending lots of time in engineering!
 

wynkoop

Member III
Episode 4: Use The Force Brett

When I went to harbor freight for a rotary tool I found a small headed grinding bit for the vibrator tool. I picked it up and went on to attack the glob of glass and resin.

The vibrator tool started to make short work of the areas I could reach. After about 15 minutes I felt I had enough clearance to try the BA stuffing box for a fit. There was no joy. The test fit showed me that even with the excess cut away the geometry was such that the bigger BA hose would not be able to slip all the way onto the stern tube.

Time to use the force............

....................of the hammer.

Having discovered the new stuffing box is a no go and also discovering new hose in the UK I resigned myself to trying to clean up the old stuffing box such that I could get it apart. After about an hour of banging it with a hammer and hitting the threads with a wire brush, then chasing them with a hack saw blade I saw the line between the two nuts! At that point I was able to unscrew both the end nut and the jam nut. Upon opening the stuffing box up I could clearly see the source of the constant river of water that had run into Silver Maiden's bilge. There was no packing material left! I discovered only what appears to be a mass of graphite on the inside of the outer nut.

The hose end of the stuffing box seems to have much either oxidation or the remnants of marine life inside it and I need to clean that out as well, but it looks like I will be pressing the original stuffing box back into service.

The stuffing box looks much better than the original photos, and I will post new photos soon, but it still needs much cleaning.

Does anyone know what size packing is needed for the original stuffing box?
 

wynkoop

Member III

Alan Gomes

Sustaining Member
BA tells me they use marine exhaust hose for stuffing box hose, so it looks like I can grab this https://www.westmarine.com/buy/shields-rubber--series-200-exhaust-water-hose-no-wire-sold-per-foot--P011_333_001_003?recordNum=1 from West Marine.

The diagram looks exactly like the old hose I cut off, so I am pretty happy I do not have to order from the UK. Now to measure for the right packing size and finish the clean up of the old bronze piece. She may swim again soon.
That doesn't seem right. Stuffing box hose has a *much* thicker wall thickenss. Take a look here. (Scroll part way down for a picture of both types of hose shown side-by-side.)
 

wynkoop

Member III
Well BA confirmed to me their stuffing box hose is marine wet exhaust hose and the old hose on Silver Maiden looks exactly like the west marine hose.
 

wynkoop

Member III
Yep Alan I have been on that page many times in the last week.

The real issue seems to be having enough reinforcing string. The West Marine hose has the same pattern and amount of string as my original based on their graphics.
 

wynkoop

Member III
Another reason I believe EY used marine wet exhaust hose is just the space available. Even with the mass of Resin and glass string mess cleaned out I do not have room for a hose that is any bigger than the original. Those measurements match the original.

I suspect if I had LOADS of money and did not mind having the boat laid up for an extended amount of time I redo the entire stern tube installation to fit the currently available crop of stuffing boxes.
 

Mark F

Contributing Partner
Blogs Author
Hi Brett,
I'm 90% sure I have marine exhaust hose on my E27 shaft log. 13 years and good so far.
 

wynkoop

Member III
The above is the original installed in 1974 by Ericsson. As mentioned above I had to slice it and do other surgery to get it out. Chandler at the new marina says he has 1 3/8 inch marine exhaust hose, so I will look at it either tomorrow or after the storm passes and if constructed the same as the above I will have all I need to re-install my stuffing box.

I am still cleaning what appears to be chunks of graphite out of the packing nut threads and front surface.

A close inspection of the stuffing box shows some wear from the shaft resting on the bronze after the packing died. I suspect the great leaking did not start sooner because of marine growth inside the stern tube.

I am going to hit a couple of machine shops before I re-install to see what they would charge to machine up a new stuffing box. Have a friend in RI that said he could do it if I can not get it done locally.

The wear is not so great that I think there will be great leaking, but I would love to know that next time I pull her I can just swap in the new part.
 

wynkoop

Member III
Episode 5 - stuffing box revenge

So we have had several days of bad weather that have kept me from the boat yard, but I have used that time to both clean up the old stuffing box and measure it in case I need to have a new one machined. There is some wear to the box, so I want to be prepared.

I declined to order the hose I found above because the local chandler claimed to have 1 3/8 hose as required. Today a trip over to his place on the way to the boat proved him wrong, so I have just lost 4 days.

On the bright side I did get the area around the stern tube cleaned up nicely and I laid down a new piece of glass cloth and resin just aft of the engine room. I felt this was needed because the stuffing box run off for the last 46 years had cut a grove through 1 layer of glass cloth. This is my first glass job, but I think it went well. I will take photos next time out when it is dry. I did not want to take the chance I might drop my phone into the resin.

So now I have ordered 2 feet of tube from West Marine and I am about to order some tube from the UK. If the West Marine hose is not suitable I know the UK source will be fine as it is listed as stuffing box hose. I am also heading back to the rubber wholesaler Monday to see if he can match my old hose. I suspect he can. I may end up with multiple runs of stuffing box hose, but I prefer to have too many than have serial disappointments, especially when the yard is being nice and not charging me lay up time.

For anyone transiting the area I can recommend DiMeglio's in Mill Basin off Jamaica Bay. The three brothers are nice as are all the boat owners I have interacted with. They also have a 60 Ton travel lift if need be. First marina/boat yard on the eastern fork of Mill Basin.
 

1911tex

Member III
Regarding dripless media in stuffing boxes.

A couple of years ago I was visiting our marina and there was a crowd of folks around a power boat used for commercial purposes that made an emergency stop and had a dripless media in their stuffing box (which I found out later). Being abnormally curious, I joined the crowd and smelled the source of the problem...the stuffing box/drive shaft in that boat was so hot it caused the hose to start smoking and smelled like burnt rubber. A diver packed the underwater shaft with something to stop the hose leaking. I did not want to look like a rubber necker so I moseyed on. Later I found out about the dripless media which caused massive drive shaft heat buildup and the resulting smoke and the shaft had to be replaced.

I like traditional stuffing box media that does the slow drip dance! I should think that anyone with a dripless packing media needs to check stuffing box temps after a motor outing on a regular basis.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
Just do not draw an incorrect conclusion from the incident. ALL shaft sealing methods have a failure mode.
:(
The "traditional" stuffing box needs to be inspected regularly for loosened locking nut, broken/corroded clamps, and cracked/softened hose.

Equally important, the failure in a high speed shaft, like any powerboat installation, is both more spectacular and a little more likely. IF the shaft alley is allowed to run dry, the meniscus of water at the mating surface against the carbon disk goes away... and that's why back in the 90's PSC was selling two versions of their "PSS", one for displacement hulls -- without a vent hose, and the other with the little air-bleed hose for boats motoring faster than a nominal 12 kts.

Later, they decided to consolidate to one system with only the vent hose. A dealer told me that their attorneys were concerned with resale of the low-speed unit to a speed boater and a possible liability problem. I could imagine that, but only as a very low % happening. Along with that, they could save some manufacturing $ by offering only one version. Kind of a 'win win' solution for the vendor.

Note that the 'hose vent' version also allows power boats to inject water at that point -- a valid solution when fitted to a planning hull where it's more likely that water would be sucked out of the shaft alley.

Each shaft system has advantages, and... disadvantages. Back when we bought our boat I wanted a solution that would lead to a dry bilge, and 25 years later it's still dry. it's nice to have in our fresh water environment, and it would be much more important if we were in salt water.

Aside: our club's dredge has a much larger diameter (but traditional) shaft packing between the Cat diesel and the 8" centrifugal main pump. Damned packing is sooooo difficult to inspect for drip rate that we finally had to mount a cam and light there and have a video monitor in the cab!
Since industry has been using 'face seals' for decades, we assume that the dredge builder uses the stuffing box to save money and also because out in the field, operators may be minimally trained in preventative maintenance. Perhaps.
 
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