Strange stuffing box behaviour..

Kopite

.
Mar 11, 2015
110
Catalina 27 Monroe MI
Hi, My boat is new to me, but I do know the box was re packed with normal flax 3 years ago. This season it has been behaving strangely. One day it's not dripping at all when not running/docked, but the next it was dripping every 10 seconds. So, I got wrenches and set out to adjust. I turned it about 1/4 turn, in the right direction, and it started pouring in a continuous flow. I had to go a further two turns before getting it back to a reasonable drip rate, and I can see a good 2-3 mm of shiny shaft now exposed. I've run it at the dock to 1500 rpm for 10 mins, and it's now dripping 5/min running and doesn't get hot. Any ideas what has happened ? Should I be worried?

Thanks, Andrew
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
Assuming that you have the correct size packing the unit should NOT be leaking at all when the shaft is NOT turning. The rule of thumb is 3-5 drips per minute, depending on the material used. Some of the packing materials will not require any dripping.

Then there are the dripless solutions (much more expensive)
 
Apr 5, 2015
50
Islander 26 Little Creek Navy Base
Hi, My boat is new to me, but I do know the box was re packed with normal flax 3 years ago. This season it has been behaving strangely. One day it's not dripping at all when not running/docked, but the next it was dripping every 10 seconds. So, I got wrenches and set out to adjust. I turned it about 1/4 turn, in the right direction, and it started pouring in a continuous flow. I had to go a further two turns before getting it back to a reasonable drip rate, and I can see a good 2-3 mm of shiny shaft now exposed. I've run it at the dock to 1500 rpm for 10 mins, and it's now dripping 5/min running and doesn't get hot. Any ideas what has happened ? Should I be worried?

Thanks, Andrew
I would be worried if it were not dripping while running (turning). Sometimes a idle shaft can get a little "slurry" in between the packing and shaft. There isn't much water pressure, so left over time the slurry turns into almost a gel, but after the shafts turns again it will break down and clear out, leaving your normal normal drip rate. I always liked 4-6 drops per minute. If it is up to around 8-10......you might want to tweek the nut to compress the packing. But again....some folks are not bothered by 10 drops.

Is your stuffing box connected to a hose, or is it rigid/integral to the hull? If it is the hose type...... the hose needs to be held securely while tightening the packing.

The shiny metal exposed on the shaft after adjustment is normal. 3mm seems a bit much, but you may have had a little gap between a couple of the flax rings. Some people get a little sloppy when they install new packing and get the packing distorted when they place the rings into the stuffing box, or they do not ensure that the end gaps are 180 degrees out from each other. I was always a neat freak when it came to packing. As long as the packing nut isn't up tight, and has more room for future tweeking.....you are golden.
 
Apr 5, 2015
50
Islander 26 Little Creek Navy Base
I have seen them drip, and I have seen them dry after sitting idle. If he has flax rings, it is nothing to freak out over when you see a occasional drip when sitting idle over time.
 

hewebb

.
Oct 8, 2011
329
Catalina Catalina 25 Joe Pool Lake
I spent some time yesterday with mine. When I adjusted last fall it was dry when not turning and 9 drips per minute running. Last time out I motored for a long time and the bilge was dry so thought I would check it. No drips while turning. Adjusting was very tricky It would go from no drips stationary to 12 while turning with a very small (almost un noticeable) change in adjustment. Packing is almost two years old with 23 hours on the engine since installed. I used WPT Graphtex Ultra Flax Shaft Packing.
 

Kopite

.
Mar 11, 2015
110
Catalina 27 Monroe MI
Thanks for the comments. I still have some travel left on the adjustment, so I'm thinking that the one of the rings in the packing must have had some end overlap, which moved when I first tightened it, losing any compression in the flax and causing the leak. It should now be seated properly and should be OK but I'll keep an eye on it. As it had been sitting incorrectly for three years, I think I'll replace when I pull the boat for the winter. ( season is nearly over here in MI. )
 
Apr 5, 2015
50
Islander 26 Little Creek Navy Base
Thanks for the comments. I still have some travel left on the adjustment, so I'm thinking that the one of the rings in the packing must have had some end overlap, which moved when I first tightened it, losing any compression in the flax and causing the leak. It should now be seated properly and should be OK but I'll keep an eye on it. As it had been sitting incorrectly for three years, I think I'll replace when I pull the boat for the winter. ( season is nearly over here in MI. )
Yes........ excellent time for repacking. Check the rubber hose/pipe to make sure it still allows for a tiny amount of flex. Leave the packing loose until you are back in the water.

You might already know this though.