When to repack stuffing box

Bill Roosa · Apr 21, 2011

Two big channel locks
3/16" packing for a 1.25” shaft
Undo the lock nut (one closest to the prop)
Back out the packing nut (one closest to the engine)
"Pick" out three complete old packings out of the packing nut being careful to get it all. This is the touchy-feely part. I have used a broken hacksaw blade in a pinch
Take the new packing and wrap it around the prop shaft at the location it will be when in place. Mark where the end is and cut it exactly at that point.
Noting where the cut end is insert it into the packing nut
Repeat with the other two packings being sure to have the cuts 120 degrees (1/3 of a circle) apart.
Hand tighten the packing nut (looser is preferred at this point)(but not too loose)

Hand tighten the lock nut
Launch the boat (no hurry on this part)
Immediately check the gland for leakage and tighten until the leak "just stops"
Tighten the lock nut
Start the motor, spin the prop and confirm that there is a slow drip (one every three-ish seconds)(you will want to be tied up correctly so you are not motoring around the marina while down below)
To balance the no leak stopped and some leakage while turning issue error on the side of more leakage while turning and "just none" when stopped. You want it to be only as tight as needed to have no leak while stopped.
Re-inspect/tighten after every use for the first 20 hours of prop time.

Ron McCoy · Apr 21, 2011

Bill, you're right on the mark. Good explanation. I recently repacked our stuffing box after 5 years and it probably needed it as the packing seemed extremely dried out. Since I have a 1" drive shaft, I use 1/4" PTFE packing with lots of the teflon lube. Once you've got the boat back in the water, start the engine and have someone motor about at just idle speed. While the boat is underway and properly managed from the helm, go below and fine-tune the packing and lock nuts. As Bill said, you'll need to fine tune the nut for the next few trips out until the packing is well seated.

Benny17441 · Apr 21, 2011

If it ain't broken, don't fix it. Even aircraft maintenance is getting away from rigid time guided replacement schedules for some parts. In the case of the packing gland it will provide plenty of warning before the stuffin needs replacing. Unlike a "dripless" which can fail catastrophically the packing gland's performance usually deteriorates gradually and can be adjusted. Worst case scenario, the stuffin can even be replaced with the boat in the water so I would not rush to make a repair. Part of the new thinking in maintenance is that everytime you replace a part there is a malfunction factor related to the new part and installation procedure. Wether it be defective parts or materials or faulty installation it adds a degree of risk non existent with the current part. This is not to say that if a part is critical for the safe operation of the vessel or if it would be to hard to replace when underway or would set you back on a trip that it would not be wise to replace promptly. With the stuffin box I think it would be a pretty safe bet that you could get another season in.

Rich Stidger · Apr 21, 2011

Princess,

Bill Roosa gave you a great cookbook process. He is correct on the size of the packing- 3/16".

However, I remembered that back in December 2010, Maine Sail gave everyone a picture story of the process.

Have a look-

http://forums.hunter.sailboatowners.com/showthread.php?t=125430

Rich Stidger · Apr 22, 2011

PrincessoftheLake said:
......and the marina wants almost $300 to do it. POTL

$$ 300

This is a stuffing box that is very easy to access too.

Maybe I should come out of retirement......

Steve Dion · Apr 22, 2011

We just did ours in the water about 3-4 months ago. I doubt that it took 1/2 hr.

If I am going to spend $300 on a repack, I would opt for a dripless and be done with it.

There was actually very little water intrusion. You just need to cut all of the material before you start the removal and re-installation of the packing. Once the first piece goes in you are nearly done!

Warren Milberg · Apr 23, 2011

A couple of thoughts on repacking a stuffing box. While I also believe in the "if it ain't broke, don't fix it" rule, I also believe in the "Law of Unintended Consequences." Some boaters continue to "adjust," i.e., tighten the compression nut on the gland long after they should have repacked it. If the packing material in your gland is old and dried out, it is possible it will score your shaft making it impossible to control the drip rate when the packing is replaced. A new shaft may then be in your future. And while replacing the packing is "usually" done fairly quickly and easily as a DIY job by most owners, unforeseen problems can arise. Chief among these are being confronted with a corroded or really cruddy compression nut or lock nut that refuse to loosen as they have been more or less frozen in place. Sometimes this can be resolved by using PB Blaster or some other penetrating lube on the nuts before trying to loosen them. Another method that reallly works, and contrary to intuition, will not damage your gland or log, is to hit a "flat" on the compression nut with a ball peen hammer, in a counter-clockwise direction, to break the grip of the crud holding it place. Finally, getting all the old packing material out can sometimes be a real chore. On my boat, for example, I only have about 4 inches between the forward side of the compression nut and the trans coupler so getting a packing removal tool into the opened nut is a challenge. I use bent needle nose pliers. So, keep all this "stuff" (pun intended) in mind if you decide to repack the gland yourself.

Don S/V ILLusion · Apr 23, 2011

One of the greatest designs of the 40.5 is the ease with which the owner has access to typical maintenance items; the stuffing box being probably the best. You can virtually sit down next to it and have room for some wrenches, knife, dental pick and a cold beer. I wish everything was as easy.