Home Boat Crew Journal Articles FAQ Links Misc
Mico Verde

(Darwin, Australia) Fun with Packing Glands

It's eight in the morning and I wake up to the shrill sound of the bilge alarm - the big one, of course. Not a good sign. We're in the Fannie Bay "Duck Pond" in Darwin after locking through yesterday with our friends on Moose. I know we have some oil in the bilge so I'm out of bed in about two seconds to shut down the pump. I flip the switch and sweet silence ensues. Now to find the source of the leak.

After you've lived on the same boat for a few years you start to get connected to her idiosyncratic routine, especially with respect to pesky little leaks. Mico is generally a dry boat so anytime there are unscheduled bilge clearings something is amiss. I start by checking the hoses and seacocks in the head. These have been a source of water in the past since after a couple of years hoses start to get pin holes around the stainless clamps. These were all replaced, painstakingly so, only a few months back so everything is dry there. Next I make the same checks in the galley and for the engine room plumping.

As I'm staring into the recesses of the engine bay I have a sickening hunch about the leak. I look aft to the packing glad (also know as the "stuffing box") and there it is staring me down in little trickles. I had always know that it was only a matter of time until I would have to work some contortion magic to squeeze into the tiny space between the aft bulkhead the engine to make the adjustment. Most manufacturer's recommend replacing the flax material in the glad every one year for power boats and three years for sailing yachts. Ours came with the boat and so was due for some service. That said in four years there was never a need for adjustment.

How do you know when the glad needs some attention? In this case it was an obvious drip, drip, drip leak when the engine was not running. You should bear in mind that most stuffing boxes are designed to drip a little bit when the engine is running (two or three drips per minute). Not doing so can cause the gland to heat up rapidly and bad things will happen. In my case the glad was packed with "dripless" packing material so no drips even with the engine enabled.

So now you have a problem - how do you adjust the packing glad? The first issue, as with most things on a boat will be access. Make sure you can fit at least your two arms onto the gland. In the case of our Westsail 32, if you don't mind undoing a few bolts the entire cockpit sole can be removed giving you plenty of room to climb in. For this task you'll need two pipe wrenches or specially designed thin crescent wrenches. Looking aft towards the prop you will see two nuts. The one closest to you, and larger of the two is the actual packing nut which when turned clockwise will compress the packing material and hopefully reduce the leakage. Just behind the packing nut is the lock nut which is used to secure the packing nut when the prop is turning.

Before you can adjust the packing nut you need to back off the lock nut. To do this you need to turn the nut clockwise, which may be counter intuitive, to allow the nut to spin away from you and the packing nut. Before doing this put a pipe wrench on the packing nut with some counter-clockwise pressure. You should now be able to move the lock not. If the stuffing box is badly corroded you will need to liberally apply your favorite penetrating oil. Once the lock nut has spun freely one or two turns you can move the packing nut. You only need to move it a very small amount - around 1/16 or a turn. More than this and it is time to replace the packing material. Don't forget to retighten the lock nut after making an adjustment to the packing nut.

To test your work start the engine. If satisified by the rate of drip, in my case this was no drips, put it in gear and run for five to ten minutes. Now stop the engine and put you hand on the stuffing box. If it is hot to the touch you need to back off the packing nut. Not doing so can lead to scoring the shaft which will cause leaks that no amount of stuffing box will resolve.

After the first time of performing this task you should now consider yourself and expert and feel free to dispense advice liberally. You will also be amazed how my power boats next to you in marinas will have "sinking boats" and have no idea that they even have a stuffing box!


SV Mico Verde