The stuffing box in my boat is dripping a little fast. Stationary, about a drip every 14 to 16 seconds, with the shaft rotating about one every 3 seconds.
I fully dried out the bilge on Saturday after our sail and came back on Sunday measured the water in the bilge as a 16 ounces. It also rained that night and I think a ounce or two was from that (through a small gap in the back locker/deck). Over a week the total amount of water is a around a gallon, nowhere near the amount need to turn on the autobilge switch which I think is around 8 gallons.
I was going to try and tighten it on Sunday to reduce the drip rate because the PO said he last changed it 5 years ago. He said it should be okay as long as your still getting drips when the shaft turns and the water is not excessive when not. However, with my luck, tightening it could make it worse either with no drips or by futzing with it to get the right drip rate, causing it to drip more, which would be a problem as I don't want an emergency haul.
My inclination is to leave it alone as is, although not a total dry bilge, not an excessive amount either and very manageable. A couple of marine mechanics I talked to suggested not doing anything to it yet unless it started to drip in the drop per second range when at rest.
I will be replacing it with a dripless in the fall, so this is just until the season ends.
Tighten it up a turn, see if this fixes it. Do it now. If it won't turn down replace the packing. This can be done with the boat in the water. Just get a piece of bicycle inner tube and wrap it around the shaft log, no water will get in the boat while you replace the packing. Fix it now before it goes completely on you when you're on a trip someplace.
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Rick I
Toronto in summer, Bahamas in winter.
My take is "it depends." If it's never been tightened after its initial install, you're probably ok tightening it a bit. You have to be careful, as over-tightening can wear grooves in the prop shaft and then you'll never get a good seal. I certainly wouldn't tighten it much. Ours, right now, dripping only rarely at rest and every 10 seconds or so under way, is still well less than hand-tightened. (I just snugged it down maybe 1/16th turn to try to reduce the drip rate a bit.)
We were lucky in this respect: Ours started dripping excessively near the end of last season, so I re-packed before splashing her in the spring.
Btw: I wouldn't go to the expense of one of those dripless systems. Gore GFO or GTU packing is said to be "virtually dripless," once properly installed, and is said to last a long, long time. Far cheaper and far simpler. I'm a strong believer in both .
If you do attempt to tighten it, (and I think you could) remember that there is a locknut that should be tight against the packing nut... back it off first. Take a gentle turn on the nut, probably no more than 1/2 turn or so to start, relock the locknut and see how things go.
It's unlikely to leak more, but overtightening can lead to excessive friction and temperature when the shaft is spinning.
__________________ Boating in BC waters since the '60s, sailing since 1981. Currently on our 5th boat, a 1984 Fast/Nicholson 345.
It doesn't sound like there is anything to fix - just an adjustment - if that. 4 drips a minute isn't going to hurt anything - and you have a bilge pump on. I adjusted mine recently and it is such an imprecise science - Whatever the drip rate it is when you adjust it, it might change in a few weeks anyway.
__________________ The next best thing
To playing and winning is playing and losing.
Robert Lee Castleman
I was in a similar situation last year. This was my first boat with a conventional stuffing box. It dripped a little more than yours. I ignored it for 6 months before I got brave enough to try and tighten it a little. I bought the special stuffing box tool, and brought some big water pump pliers and a pipe wrench. I sprayed some liquid wrench onto the lock nut, tapped it a little with a hammer, and waited a day.
The next day I removed everything from the rear berth so I had good access, put the stuffing box wrench in it, and used the pliers to loosen the lock nut. No go. The stuffing box wrench would slip off. So I tried the pipe wrench. I used gentle pressure and the lock nut loosened. I tightened the coupling about 1 turn. Way too much, no water dripped at all. I ended up with 1/4 turn of tightening. Now I get 0 drips when the shaft is stationary and 1-2 drips a minute when the shaft turns. The shaft stays nice and cool.
I had originally planned on going to a dripless, but now I'm not going to bother.
I should have made the adjustment 6 months before. It was really no big deal.
Barry
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Barry Lenoble
Day To Remember, 1986 O'day 35
Mt. Sinai, NY lenoble@optonline.net
Thanks to all of the replies. My original postion was to leave it alone for the season, but I went sailing yesterday and checked the drip rate after a few days of sitting idle before we motored out of the harbor. At rest, 1 drop every 45 seconds. Not desirable, but managable.
So we went sailing and then motored for 20 minutes back to the hook after the sail. Checked the drip rate and the rate was once every 4 seconds immediately after stop, check again just before leaving the boat (2 h later) and it was once every 7 seconds. I used an eye dropper to put some PB Blaster on the lock nut before we left incase I needed to do something to the box the next day.
This morning, the drip rate was once every 14 seconds, about 3X faster than last week. So we needed to do something.
My wife and I worked together to get the locknut to move. Once free, I turned the pack nut and then we resnugged the locknut. We started the motor and headed out of the harbor while I monitored the drip rate. After 3 minutes, I hadn't seen a drip, so we dropped the speed to crawl and went back to the hook. I backed off the pack nut maybe 10 degrees and retorqued the lock nut. Refired the motor and headed out again. I couldn't get a drip rate when the shaft was in the 2000+ rpm rate because the water was being thrown off, but at idle speed (1500 rpm) I was getting 1 every 6 seconds and then at rest 1 every 40 seconds as soon as the motor was into neutral. So it is considerably better than before, but not the 3 drips minute when shaft turning, none when not.
This is the first time I adjusted a packing nut and it is a finicky adjustment. Less than a 16th of a turn makes the drip rate go from a lot to none. My packing material is about 6 years old and based on my adjusting experience, it is maybe nearing the end of it's life.
I was getting 1 every 6 seconds and then at rest 1 every 40 seconds as soon as the motor was into neutral. So it is considerably better than before, but not the 3 drips minute when shaft turning, none when not.
Whatever you do please don't go by suggested drip rates on old packing or with an old and worn shaft.
The best thing to do is adjust it for the least amount of dripping without any heat build up and that will be the best you can do.. Heat = BAD..
You packing is likely at the end of it's useful life if a 1/16th of a turn made that much difference. As I've stated before, a 1/2 a nut flat to a full nut flat of movement is a lot in terms of stuffing box adjustment. On old packing never do more than one nut flat at a time without running in gear for about 15 to 20 minutes before the next adjustment. Old flax can be finicky and it gets hard and less compressible / adjustable with age..
I definitely would not worry about drip rates like that.
Mine drips at rest, and drips more when running.
It really must drip when running or it does not cool so well.
The seal is not designed to be perfect.
Packing can last a long time indeed.... mine is in its 15th year.
It has dripped for the whole time.