| There
are few areas of neglect of a boat that can cause more
costly damage so quickly than a propeller shaft stuffing
box that is throwing water around an engine room. And
while surveyors have been warning boat owners about
this potential costly problem for decades, we continue
to see large numbers of boats where the owners seem
to be unaware of this, and that this apparently common
knowledge is still not so common. To
give you an idea of just how costly the failure to
realize that your propeller shafts are throwing water
around your engine compartment can be, consider that
we recently saw a generator set mounted between two
engines, where the side of the generator engine block
had been corroded almost completely through. The leaking
stuffing box had literally destroyed the generator.
In addition to that, the battery charger, engine starter
motors were damaged, along with a large number of
electrical connections were corroded and caused equipment
failures. All totaled, we estimated that this seemingly
"minor problem" had caused upwards of $15,000
worth of damage.
All because of a stuffing
box throwing water and the lack of an ounce of prevention
that costs no more than $5.00 and a half hour of time.
You can add to the
likely resulting damage rusted shaft/transmission
couplings that will have to be cut off and replaced
the next time you have to pull a shaft. That, because
the bolts and couplings are so badly wasted that they
no longer come apart and have to be cut. This involves
a huge amount of labor plus the costs of new couplings.
Figure in a few grand more for that damage.
Unfortunately, this
is an all too common happening. Sometimes it's not
just a failure to install splash guards over the stuffing
box, but a failure to fit the guards correctly so
as to contain the spray. A stuffing box, also called
a packing gland, doesn't have to leak much. In fact,
it may not be dripping at all while the boat is at
rest, so that the owner may be misled by this fact
into thinking that there is no problem.
Moreover, when you
look at a stuffing box while underway at speed, you
may not be able to actually see what is happening.
When a shaft is rotating very fast, it can be creating
a very fine mist of salt water spray. So fine that
it is not visible. But if you place your palm over
the stuffing box, it will come away wet. To make matters
worse, your engines are ingesting that mist and severely
reducing their life span.
This problem is so
easily preventable, that no boat owner should fail
to do it. Whether your stuffing boxes are leaking
or not, or whether you have "dripless" glands
installed or not, never think that the shafts cannot
be throwing water.
To create an effective
splash guard, the guard needs to completely surround
the point where the shaft extends into the gland opening.
We often see splash guards cut from a piece of hose
in such a way that it only covers the top side of
the shaft, which continues to throw water upward from
the bottom side of the shaft, making this guard ineffective.
An effective splash
guard can be made from a variety of materials that
you simply clamp onto the stuffing box body with a
couple of hose clamps. Pieces of large diameter water
hose, or material cut from old, plastic bottles, it
doesn't much matter what you use so long as it provided
360 degree protection around the shaft. The
amount of coverage should be at least 4" forward
on the shaft from the opening.
In most cases, it takes
no more than half an hour to do the job, and can end
up saving you thousands of dollars in unwanted damage.
Oh, and by the way,
after you install them, don't get the idea that you
never have to look that way again. There is a great
deal of vibration going on in that area, so be sure
to check it out occasionally to be sure your splash
guards haven't slipped out of position. They often
do.
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