Stuffing box , seizing ?

[paulg222]

Originally Posted by Boatyarddog

Quite sure it's a packing gland in these pictures.
There's green bronze in the frame.
I'm not a fan of dripless, not robust enough for me.

Based on what I heard from previous owner yesterday (he said it was dripless, but picture suggests otherwise), my guess is this is a conventional box that was filled with so called "dripless stuffing" or Graphite Fiber GFO type. Which is supposed to last longer and does not require a constant drip of water.

It seems I probably have 2 choices, either try to make an on the water adjustment of the stuffing box (perhaps just loosening slightly the compression), or have the boat hauled and let the pros do it.

[MicHughV]

...yep...from where I'm sitting that is a regular old time stuffing box......the " dripless" may be this new fangled teflon coated stuffing box material...

Here's another clue, there is a outer round ring plate that gets screwed onto that stuffing box.....you can generally tell from the number of threads still exposed on the main body of the stuffing gland how much material is packed in there...as the top plate is screwed down, generally with the assistance of a stuffing box wrench....

if there is only a few threads showing it generally means the round plate has been screwed down to it's max position, meaning only a bit of packing material left in there...

looking a the video again, I see a white ring around the prop shaft, just ahead of the stuffing box, which may show the original location of that outer stuffing box ring nut, meaning that outer ring is screwed down tight....tight enough to cause sufficient grab on the prop shaft...

my take on the matter is to remove that outer ring, and insert some new gland material.
..it can be done with the boat in the water, yes, it will leak while you do it, but if you pre-prepare circles of stuffing material prior to removing that ring, it will only leak momentarily.

The standard way of doing this is wrapping some stuffing gland material around the shaft to measure it, cut it exactly to fit around the entire perimeter of the shaft. Cut 2 or 3 of these circles and have them ready as you remove the nut....insert 1 circle, tighten the gland nut to push that material in... and then remove the nut again, to insert the next circle, have the cut ends 180 degrees from the first circle, re-attach the nut and tighten again...2 circles may do the trick, but if you need to insert 3...or even 4...have them all ready and position them at 90 degrees from the 1st and 2nd.

Not being there, hard to make any definitive detective work, but my guess is that the gland nut is tightened down hard on whatever remains of the material inside the stuffing box and the shaft is binding up.

Yes, it may seem to free up, but that could be the gland getting hot from friction and expanding just sufficiently to allow the shaft to rotate.

[DeValency]

Not normal and put you at a high risk and at least additional damage to the shaft, hull and flooding... it will just get worse.
I would haul the boat right away and get ready for a serious repair that may go beyond the staffing box alone: shaft, cutless bearings, tube etc.

Originally Posted by paulg222

Here is a link to a short 10s video of my stuffing box shown while the engine is running: https://streamable.com/f8i4hi

During the video, you'll see 2 incidents of what I'm talking about. The first is about 3-4 seconds in, the second at around 8s.

Both times you'll be able to see a slight rotation of the stuffing box. It sort of quickly rotates counter clockwise and then back (I think). Small rotation. Also there is a noise when this happens (which is what alerted me to it).

Note this was just after I launched the boat this Spring. I did not service the box before launching.

What level of concern should I have about this? Is it normal, does it need immediate attention?

It does not happen all the time. After noticing this it seemed to stop and I did end up motoring for about an hour and did not hear that noise.

[gulfislandfred]

I think your stuffing box is grabbing on the shaft, causing the hose to flex a bit. As others have said, the hose may be damaged, and the whole thing needs to be cleaned up, maybe new hose, definitely new packing, and adjusted properly.
DO NOT REPLACE WITH A DRIPLESS SHAFT SEAL!!!! They sink boats. Here in the Salish Sea, many commercial fishing boats have added a grease fitting to the stuffing box, or the insite stern tube fitting, so you can pump water proof grease into the stern tube and stuffing box. If the packing is too tight, the heat melts the grease, and lubricates the system (the packing should not be too tight, though) If the stuffing box is hard to reach (like under a few tons of ice and salmon), the grease fitting can be mounted on a small copper pipe, where it is accessible. My old Marcon Sabre sailboat came from the factory in the UK with a copper tube and grease fitting conveniently located next to the engine, to grease the stuffing box.


To fix this right, you need to pull the shaft back, replace the hose that holds the stuffing box, clean up the shaft and stuffing box, and repack the stuffing. If you put in a grease fitting at the same time, you will have a better than new system.


You might get by for the season (look at that hose very carefully! It can sink your boat if it lets loose) by repacking the the stuffing box, and clean up the shaft where it rubs on the packing. If there is deep corrosion on the shaft, you can fill it with epoxy (marine tex will do), and smooth it with 400 grit (or 1000 grit) wet and dry sandpaper.


If you're where the water is warm, or you have a diver available, you can wrap plastic bags, then thin bungee cord around the prop shaft on the outside, where it exits the hull, and get it pretty sealed up, so you can work inside without the excitement of water flowing in around the shaft. If you're just replacing the packing, and do a quick clean/smooth on the shaft, you can just wrap a rag around the shaft and let your pump deal with the water that comes in.

[paulg222]

Latest update> The mechanic at the marina I'm at went out to the boat (on a mooring) and "put a wrench on" the stuffing box and said that the hose flexed a lot and he felt the hose was in poor shape and could break off.

Plan now is to haul it and fix it. Since the hose needs replacing (and possibly the stuffing box too) they have to pull the shaft back, and we are hoping there is enough room to do that without them having to remove the rudder.

Sadly it is so busy at the marina (with everyone else trying to get in the water) that they can't haul it right away, but hopefully next week. So while I made it into the water at the perfect time for some of this good weather hitting us in the Northeast, I can't really use the boat.

Well I could use it without the motor, but I'm not so confident in my sailing skills yet to get on/off the mooring with other boats nearby and some limited depth around near our mooring, not to mention some currents in our area that crop up and can make it hard to get back to the marina if wind dies a bit and you have only sails. But makes me appreciate the old days, and as soon as this is fixed I'll be practicing some of those non-engine maneuvers more.

[DeValency]

As suggested... Boats are usually designed to enable shaft pull out without removing the rudder (or cutting the skeg... ). Be prepared for other findings once you start the project. Good suggestions on keeping a (good) stuffing box vs. dripless. Also make sure to check the engine mounts at the same time.

And an excellent reminder for all of us to practice anchoring and mooring return without engine. I had the unfortunate opportunity to practice it in Martinique in January - was fun!

Best of luck

Originally Posted by paulg222

Latest update> The mechanic at the marina I'm at went out to the boat (on a mooring) and "put a wrench on" the stuffing box and said that the hose flexed a lot and he felt the hose was in poor shape and could break off.

Plan now is to haul it and fix it. Since the hose needs replacing (and possibly the stuffing box too) they have to pull the shaft back, and we are hoping there is enough room to do that without them having to remove the rudder.

Sadly it is so busy at the marina (with everyone else trying to get in the water) that they can't haul it right away, but hopefully next week. So while I made it into the water at the perfect time for some of this good weather hitting us in the Northeast, I can't really use the boat.

Well I could use it without the motor, but I'm not so confident in my sailing skills yet to get on/off the mooring with other boats nearby and some limited depth around near our mooring, not to mention some currents in our area that crop up and can make it hard to get back to the marina if wind dies a bit and you have only sails. But makes me appreciate the old days, and as soon as this is fixed I'll be practicing some of those non-engine maneuvers more.

[paulg222]

The boat is finally fixed and back in the water.

The hose leading back from the stuffing box was replaced. Mechanic said it was very brittle, came apart when he was removing it. The stuffing box itself was able to be re-used. I didn't get a ton of information from mechanic on why the "seizing" was taking place in the first place. The rudder did not have to be dropped, he was able to pull the shaft out of the engine and that gave enough room to slide everything off.

Thanks everyone here for the helpful advice.

[Boatyarddog]

Originally Posted by paulg222

The boat is finally fixed and back in the water.

The hose leading back from the stuffing box was replaced. Mechanic said it was very brittle, came apart when he was removing it. The stuffing box itself was able to be re-used. I didn't get a ton of information from mechanic on why the "seizing" was taking place in the first place. The rudder did not have to be dropped, he was able to pull the shaft out of the engine and that gave enough room to slide everything off.

Thanks everyone here for the helpful advice.

So happy that you were able to get this done.
Were you able to watch the process?
It's always good to see how it's done.
Next time someone asks for advise you'll know how it's done.

SV Cloud Duster

[mvweebles]

Thanks for taking the time for an update. Sounds like you were a few engine hours away from a really bad day.

Peter.