Stuffing box: To drip or not to drip?

[CalypsoP35]

I have a pretty old stuffing box and had to repack it this summer. It's well over 10 years old and I'm thinking this winter I will replace it.

The question is whether I should go to a dripless stuffing box. I'm tired of having water in my bilge, and that got me thinking about a dripless stuffing box. I have a 30hp Universal diesel engine with a 1" prop shaft, runs at 2500rpm. Typical engine use is 2 hours a week during the summer, unless we get becalmed on a weekend trip to an island which could result in running the engine for 5 hours at time.

Other than the obvious one, the drip, what are the pros and cons of changing to a dripless stuffing box?

[svHyLyte]

If you have the room for it and your shaft is true, there are few disadvantages to a dripless shaft seal. On the other hand, a "10 year old" stuffing box really isn't "old" although the packing may (have) need (needed) replacement. If the packing material is of the newer self lubricating type, one really doesn't need "drips". If you are using the old style greased flax packing, the rule of thumb was one drip every 20 seconds with the shaft still.

FWIW...

[JimsCAL]

A quality bronze stuffing box will last for decades. Does need repacking from time to time, but its not a terribly hard job. While unlikely, if a dripless unit starts to leak, you are in trouble and will need a short haul. You can repack a stuffing box in the water if necessary.

[CalypsoP35]

When I repacked I used the old greased flax material. I didn't even know about the self lubricating packing material. I'll do some research on that and re-evaluate the condition of the current stuffing box when I haul out this winter.

I don't really know how old it is, it's probably closer to 15 years years old. That's when the boat was repowered. I'm assuming they replaced the stuffing box at that time.

I appreciate the comments. Thanks!

[fcsob]

My stuffing box is 34 years old. I use the GTU stuffing.

[Hartley18]

Does your stuffing box have a grease nipple on it??

If so, adding some grease should stop any drips whilst the shaft is still.

[CalebD]

The bronze stuffing box in my boat is 43 years old and still quite functional as well.
Traditional stuffing boxes like this begin their failure mode with more dripping (needs new packing) then usual. This design likely goes back to the age of steam power.
With the newer 'dripless' stuffing boxes when they fail they can fail catastrophically with little or no warning.
Use the high tech packing material (GFO or GTU) instead of flax and save yourself the expense of the upgrade.

[sapo]

I repacked my traditional stuffing box with the dripless, teflon putty material. Still drips a little. How can I tell if I'm tightening it too much?
thanks
sapo

[CalebD]

sapo,
If you read this entire 'how-to' on stuffing boxes you will read that the putty material is not necessarily the best choice: Re-Packing A Traditional Stuffing Box Photo Gallery by Compass Marine at pbase.com
Some swear by it. I've never used it and had great results with the 'GFO/GTU' type packing material.
YMMV, IRMV.