Unusual stuffing box

[Connell89]

Hi all, I have a 1977 cornish crabber and was going through some maintenance on the hard which included repacking the stuffing box. To my surprise there is no stuffing in there at all, just marine grease. It has run fine with intermittent dripping for the 2 years I've had it, as well as however long the previous owner had it this way. I have the following questions:

1. Although there was no packing, should I add some anyways? Perhaps it was done incorrectly and there should have been packing all along.

2. If so, how would I do that? I know how to do the packing, but the issue is twofold: there's a brass groove that I don't know what to do with (which is absent from other traditional stuffing boxes from what I can tell), and there is really not much space above the groove within the nut itself. Enough space for 1 or maybe, if I'm lucky, two rings worth of packing material.

Thanks in advance.

 

[shemandr]

To get far over my skis, because I'm bored tonight, I'd say yes pack it. It doesn't look that different than another stuffing box. Maybe it hasn't leaked in the past is because it may not be under the waterline. So maybe grease was adequate. Nevertheless I would pack it. If it's only a turn and then some it's better than nothing. Maybe you need to use thinner packing.
I'd welcome an dissenting view because as I said I'm bored.

 

[ggrizzard]

I agree with Shemandr. You're 3/4 the way there already. Go for it.

 

[Sailor Sue]

In the very first picture there appears to be a hole in the main shaft tube. Could that be for a zerk fitting, and that grease is actually used instead of packing?

 

[jviss]

Why not just ask over here:
Cornish Crabbers Club

 

[JoeWhite]

Or, replace the stuffing box with one that uses the stuffing box wicks and go sailing with confidence.

 

[Tally Ho]

Or, replace the stuffing box with one that uses the stuffing box wicks and go sailing with confidence.

Or upgrade to something dripless and sail with a dry bilge

Greg

 

[jssailem]

I have not seen a stuffing box that uses only grease. Grease only would eventually wear/leak out and the shaft log would leak.

Here is the antaomy of the typical stuffing box.

I would put packing into the unit. Size would be based on box design. Or as Greg (@Tally Ho ) suggests, while you have it apart install a dripless shaft seal.

 

[jviss]

I have never seen a stuffing box with a grease fitting (Zerk). Did you create that pic or find it on the web?

 

[Ralph Johnstone]

This is where you will find the grease point on an industrial high pressure pump.

Where the packing is shown, you will find a small perforated ring called a lantern ring :

And one or two rings of packing on either side of the of the lantern ring.

Grease is then injected with a grease gun and is held in the lantern ring under pressure to ensure no leakage.

Make no mistake about it, the so called marine packing glands that we as small boat owners are fed, are absolute $hit !

They have everything working against them. Right from the way they tear up the packing on installation all the way to the lack of a bevelled packing ring.

This is a true packing gland for a 1-1/4" dia. shaft. I have yet to ever see anyone make one for a 1" dia. shaft and yet I have seen them as small as 1/2 dia. for industrial pumps:

Figure five shows a proper packing gland without a grease fitting and lantern ring and it's still light years ahead of the crap we're forced to use.

If you were ever able to install a packing gland like the one below you would have no leakage, and none of the replacement requirement of a mechanical seal every 7 years as recommended by the manufacturers.

As long as one greased this gland perhaps once per year, it would perform flawlessly in our congenial sea water environment for many years. The absolute worst thing that could happen if you ignored this gland would be it's starting to leak ever so slightly.

I thought I heard that things can happen to a dripless mechanical seal if it is completely ignored for years on end. No warning either.

 

[jviss]

@Ralph Johnstone , you rock, I always learn something from you!