Stuffing Box - Setup and adjustment questions

[Hermia II]

Change it as soon as you can for a drip-free stuffing box and forget the problem. This old type of stuffing box is an outdated item.

[GwalarnYacht]

Originally Posted by Mark Thurlow

NO,NO<NO. It is not a grease nipple or even a grease point. These stuffing boxes take Teflon coated braids that wear away over time.

The cap on top is a seawater flushing tube driven normally as part of the engine cooling raw water system. Many times these hoses are disconnected and capped like yours is. Reason given to me was to cut down on sea water fail points. The gland will work without the raw water if the correct lubricated braid is used.

I suspect you are having adjustment issues either because you have used the wrong sized braid or some old dry braid was left inside the coupling when you filled it up with new braid. Either way check the braid and make sure old stuff removed.

I notice that your port side stud is either screwed in too far or is too short to allow you to fit a second/lock nut as there is on the starboard side. I would fix this as well.

Hi, thanks for your feedback.

I did use Teflon GFO 6.4mm packing rather Graphite (I stated that wrong in my initial posting). I have 4 rings in there. They nicely did fit in, so I think they are the right size. My shaft is 1 1/4 inch. I made sure I got all the old packing out, took me hours to do so. Once I had them all out I had a decent amount of water flowing in, which I also took as a confirmation that I had removed it all.

What you are saying about the "flushing tube" I don't really understand. How would that work with the Raw Water system? What's its purpose? It seems that the "flushing tube" is behind the packing and exposed to the shaft. If you open it, and there is no grease in it, plenty of water enters the boat.

I'm aware of the stud. I had to replace one and had only a shorter one. I will fix that some other day.

[Uncle Bob]

Hi again, I see that you have attracted a lot of opinions, may I suggest that you fill the cup with grease, screw it down and then refill the cup, see how it goes, costs next to nothing in materials or time and you can replace the "outdated" gland or do whatever you feel is appropriate later.

[GwalarnYacht]

Originally Posted by Uncle Bob

Hi again, I see that you have attracted a lot of opinions, may I suggest that you fill the cup with grease, screw it down and then refill the cup, see how it goes, costs next to nothing in materials or time and you can replace the "outdated" gland or do whatever you feel is appropriate later.

I did that yesterday. I realised with the shaft not turning it is very hard to push the grease through by just screwing in the cap, so I tried while running the engine and that turned out to work very easy. Too easy in fact. Grease load after grease load kept on "disappearing" in the shaft. I did more than 10 caps full of grease and it seems that there is still space for plenty more. I will do some more today.

In the meantime, the temperature/drip issue hasn't really improved, but I do need to do more tests.

[Uncle Bob]

I just had a thought (yes it was painful), when you replaced the packing you did offset the join in each layer by 180 degrees and the ends were cut at 45 degrees didn't you?

[Reefmagnet]

Originally Posted by GwalarnYacht

Hi, thanks for your feedback.

I did use Teflon GFO 6.4mm packing rather Graphite (I stated that wrong in my initial posting). I have 4 rings in there. They nicely did fit in, so I think they are the right size. My shaft is 1 1/4 inch. I made sure I got all the old packing out, took me hours to do so. Once I had them all out I had a decent amount of water flowing in, which I also took as a confirmation that I had removed it all.

What you are saying about the &quot;flushing tube&quot; I don't really understand. How would that work with the Raw Water system? What's its purpose? It seems that the &quot;flushing tube&quot; is behind the packing and exposed to the shaft. If you open it, and there is no grease in it, plenty of water enters the boat.

I'm aware of the stud. I had to replace one and had only a shorter one. I will fix that some other day.

I suspect there is some confusion with other styles of stern gland. Some glands seal so well they require 'burping' to remove air and others have seals of a particular design that require a flow of water to keep friction heat and/or wear down. Both of these types require some means to either add a flow of water or bleed off trapped air on the stern tube. Neither applies to this type of gland in question. I suspect this style of gland was intended to be used with shafts driven by rigidly mounted motors and as such they have little tolerance for shaft movement. This means any lateral shaft movement will act on the packing and this, in turn, results in problems trying to keep the packing sealing well. The solution is to pump grease behind the packing to improve the sealing without the need to excessively compress the packing. It's also worth noting that the grease actually tends to work it's way past the packing due to water pressure in the stern tube and once that threaded connection has grease in it, it is also unlikely to leak so grease cups or hoses can be disconnected for short periods without worrying about water squirting out from it.

[Squanderbucks]

If you go to submar.com you can search through the Tony’s tips and see how a grease fitting is setup on a a traditional prop shaft packing gland. You will notice the fitting is placed in the gland right atop the packing rings. To allow the grease to spread around and through the fibers of the packing. Putting it after the packing only works as a very temporary waterproofing. As soon as it is run for a few minutes it gets washed away.

[manitu]

I have the same stuffing box on my boat , exept whithout the grease box. I'm changing it, as my new motor needs more play because of softer motor mounts. + I dont like not knowing when I run out of grease. When I bought the boat in france, I put a full tube of grease into the axle tube, behind the seals. It has lasted the trip home , motoring to Norway, and two years of occasional use. Now, after two years, when the boat sits for a month it starts to drip , but running the engine for two minutes and it stops. .manitu

[Squanderbucks]

Regarding the stud replacement. Looks like you just put in a SSBolt. You need a piece of “ready rod”. As soon as you screw in the bolt you have to the point it bottoms out you will not be able to adjust the shaft stuffing any further.

The threaded rod with double nuts is there to not only be a safety lock but allow you to keep the forward section that holds the packing “cup” aligned straight on the shaft by turning each side an equal number of flats at each adjustment and have the ability to use the full range it was built for.

[Searles]

After nearly sixty years in the trade ,and working on all types of shaft and shaft seals ,I will go for that being a grease cup,would not use graphite in a salt water application.⚓️👍

[GwalarnYacht]

Originally Posted by Uncle Bob

I just had a thought (yes it was painful), when you replaced the packing you did offset the join in each layer by 180 degrees and the ends were cut at 45 degrees didn't you?

Yes, I was offsetting each ring by 90 degrees (4 rings) and cut at 45 degrees.

[GwalarnYacht]

Originally Posted by Squanderbucks

Regarding the stud replacement. Looks like you just put in a SSBolt. You need a piece of “ready rod”. As soon as you screw in the bolt you have to the point it bottoms out you will not be able to adjust the shaft stuffing any further.

The threaded rod with double nuts is there to not only be a safety lock but allow you to keep the forward section that holds the packing “cup” aligned straight on the shaft by turning each side an equal number of flats at each adjustment and have the ability to use the full range it was built for.

Its a threaded SS Rod, not a bolt.

[GwalarnYacht]

Originally Posted by Squanderbucks

If you go to submar.com you can search through the Tony’s tips and see how a grease fitting is setup on a a traditional prop shaft packing gland. You will notice the fitting is placed in the gland right atop the packing rings. To allow the grease to spread around and through the fibers of the packing. Putting it after the packing only works as a very temporary waterproofing. As soon as it is run for a few minutes it gets washed away.

The website you mentioned is some oil & gas pipeline control company?

[GwalarnYacht]

Originally Posted by RogerLloyd

The shaft seal needs grease. The grease arrives under pressure via a tube which connects by the fitting you have observed. The other end of the tube is connected to a special grease gun. This "gun" is a cylindrical tube full of grease. The bottom end of the tube is screwed into a base plate which is screwed to the floor inside a cockpit locker. The other end of the cylinder has a "T"-handle. When the T-handle is turned clockwise grease is forced out of the cylinder and down the tube to the stern gland. The T-handle should be turned about half a turn every 4 hours or so when motoring, and also after the engine is switched off, in order to seal the tube while the boat is left to itself. When you have exhausted the grease in the cylinder, unscrew the cylinder from its base plate, and put that end into tin of e.g. Ramanol grease (this is suitable for under water and does not leave a residue, and hopefully is not too bad for the eco-system). The grease in the tin should have a top-plate which has a hole in it. Push the open end of the cylinder down onto this hole, and the grease enters the cyclinder through the hole in the top-plate. You will also have to pull the T-handle out to suck the grease in. When the cylinder is full, screw it to the base-plate again and turn the T-handle clockwise until resistance is met. See
http://www.asap-supplies.com/product...-150ml-2-74905

WOW, who would have thought of that, but I think you are right. Thanks for that tip.

[DeValency]

Originally Posted by Hermia II

Change it as soon as you can for a drip-free stuffing box and forget the problem. This old type of stuffing box is an outdated item.

Agree with you in general. When, as a kid, repowered my first keel boat, a Dufor, in the 80's, I chose a Volvo shaft seal that performed perfectly, including with the owner who bought the boat from me and kept her for 30 years(!).

However, in most boats, replacing it is a real project - unless if there is an adapter to connect a drip-free stuffing box and seal it to the existing - and! if you have enough space...