Posted by rick_simonds (rick_simonds@…>)
— In freedomyachts2003@yahoogroups.com, “miloblues04”
<miloblues@a…> wrote:
Help! My stuffing box is leaking (if it is a stuffing box). How
goes it tighten??? Starting from the shaft, theres a large nut(?)
with sprockets on it, then a small diameter something with a
hoseclamp and grounding wire, then a smooth metal ring, then a
large
diameter short rubber hose with hoseclamps.
The large nut doesn’t appear to tighten to anything.
The leak is coming from where the shaft exits/enters the large nut.
Can someone please let me know how to stop the leak? Thanks in
advance,
Milo
I’m not sure what the “smooth metal ring” is and I’m confused
about “The large nut doesn’t appear to tighten to anything” (it
doesn’t bump up to anything but the “sprocket” nut is on some
threads, right?) but the rest sounds like a standard stuffing box. If
so, except for it’s awkward location, it’s easy to adjust.
The “sprocket” nut is actually 2 nuts screwed tightly together, a
packing nut and a shorter threaded ring. The ring acts as a jam nut
to keep the packing nut from loosening. I’m not at the boat right now
and I can’t remember absolutely if the ring is forward or aft of the
packing nut, though the ring would almost have to be aft, toward the
propeller. You can look at it and tell, you will see a band without
sprockets around the circumference of the sprocket nut, that band is
the dividing line between the ring and the packing nut. The packing
nut is the longer part, the ring is the shorter part. They are both
threaded on to the “small diameter something with a hoseclamp and
grounding wire” part, the stern tube. For this job you’ll need 2
small pipe wrenches that still fit the sprocket nut. The floor of the
cabinet under the galley sink comes apart; take out all the parts to
get the very best access you can. Also wire brush and soak everything
with penetrating oil for a little while before you start.
Hold the packing nut with one pipe wrench while breaking loose the
ring with the other wrench. (Turn the ring so it goes farther on to
the stern tube, counter clockwise when viewed from aft looking
forward.) It’s awkward and tight quarters in there but this can be
done, just look at the dividing band between them and make sure one
wrench is ONLY on the packing nut and the other wrench is ONLY on the
ring. You should only need to loosen the ring less than a quarter
turn with the wrench before it can be turned by hand. Loosen the ring
(turn it farther on to the stern tube) a few turns. The packing nut
can now be tightened farther on to the stern tube, mostly by hand.
Tightening the packing nut farther on to the stern tube pushes the
packing inside the nut tighter against the shaft to seal out the
seawater. You want it to still just barely leak to insure that enough
water is getting to it to cool it.
Tighten the packing nut onto the stern tube until the shaft drips
very, very slowly, ideally maybe 1 drip every 5 to 10 seconds. Be
dainty if you need the wrench to tighten the packing nut, you should
only JUST BARELY need it, if at all. Now with one hand hold the
packing nut so it can’t loosen, retighten the ring against it with
the other hand. Now hold the packing nut with one pipe wrench so it
can’t loosen and firmly screw the ring against it with the other
wrench. Concentrate on not letting the packing nut loosen while doing
this, youre just trying to lock in that setting by jamming the ring against the packing nut so the packing nut cant loosen by itself.
They don’t have to be jammed together screaming tight, just very
firmly.
If this doesn’t work, if tightening the packing nut doesnt stop the leak, then the packing material is shot and the packing nut needs to be repacked. If so, it uses (from memory) 3/16" square flax packing material. You don't need to haul the boat for this, I've repacked mine in the water for 20 years. Basically you pre-cut 3 pieces of packing material into rings to just exactly fit around the circumference of the shaft so their ends just touch each other. Loosen the ring and take the packing nut completely off the stern tube. Pick out the cruddy old packing from inside the nut (they make a corkscrew-looking tool to do this but about anything will work; needle nose pliers, a straightened fish hook is good, tweezers, hemostats, a tiny bent screwdriver .… Gather an eclectic collection of tiny "hooking," "picking" and "grabbing" tools before you start.) Then you carefully wrap your 3 ready-cut rings of new packing around the shaft and push each of them into the nut (try to stagger the seams in the rings so one ends up at 12, one at 4 and one at 8 o'clock on the shaft. Easier said than done, but try for that anyway and dont worry about whatever you end up with.) Then you screw the
packing nut back on to the stern tube and complete the adjustment and
locking process as above. You want everything to be organized and
prepared in advance for this job. With the packing nut off it’s not
like the submarine movies where water is shooting across the room but
the stern tube will be flowing constantly, say, a gallon a minute.
There’s not a lot of danger to this job but still, you want to test
your bilge pump first and, your first time, you really might want
someone on hand who has done it before.
(Oodles of disclaimers here: I’m describing how mine works, I haven’t
seen your boat, I’m describing a process that opens up a hole to the
sea, good luck, don’t break anything, don’t blame me, Mr. Murphy
loves sailboats, yadda, yadda, yadda…)