By John Barker, Dun Wurkin #45
Saturday 1 November 2014 at 6 PM, after procrastinating for 5 months while the stuffing box leaked and was retightened and leaked some more, I decided to tackle the job while the boat was afloat in its slip (after fortifying my courage aboard the boat next door with bold talk with friends and a beer).
Knowing that the job was coming, I began spraying the threads of the lock nut and packing nut with WD-40 months ahead of time. I sprayed them at least three times between May 2014 and November 2014. I also began assembling the tools I would need and would store in a special tool box labeled Stuffing Box Tool Box. Here is a picture of the tools.
Starting in the upper left of the photo and working around is the 5/16 packing material, an 18” piece of line, some 1/8” wooden dowels, WD-40, and a hammer. Then there is the chisel (it would work but I only needed one about 6” long, the stuffing pick (the 4” long silver colored tool with a corkscrew tip and a ring for grasping at the other end – my sincere thanks to the former owner, Peter Lukken, for having this tool onboard because the one I bought was too big), and the last tool is the chain ratchet. Without the chain ratchet to turn the packing nut I could not have done the job. The packing nut wrench that came with the boat was too small for the nuts, and there is not much lateral room to swing it anyway. I also used a child’s toothbrush for cleaning out the threads inside the packing nut, a sharp razor blade to cut the new packing material, a short section of pipe the same diameter as the shaft to use to cut the packing material to the right length, and I also had a short handled heavy hammer in the Stuffing Box Tool Box in case it was needed, but these four things are not in the picture. Naturally I was out of paper towels and simply used (ruined) a towel from the shower.
I began by testing my bilge pump which sits about 20” forward of the packing not. It worked fine and I thought it could keep up with the flow of water while I did the job. It did.
Next I sprayed WD-40 on the threads and on the shaft forward of the nut. The shaft forward of the nut was fouled with some bilge gunk so I sprayed it, then wrapped the 18” piece of line around the shaft and then alternately pulled on each end of the line, rapidly spinning the line around the shaft and cleaning off the gunk.
Next I tapped a corner of the locking nut with my hammer and it moved slightly, so a couple more taps and I could turn it by hand and back it away from the packing nut. I did not need the chisel because I had been spraying with WD-40 since May when I did need the chisel to first start tightening the nut to stop the leak months ago.
Next I put the chain ratchet on the packing nut and it worked like a dream, taking the nut all the way forward and off the threads.
I then picked out the old stuffing material. This took a while, and next time I will wear gloves. It takes a great deal of pulling force to remove the old packing material and each time my hand slipped my knuckles crashed into either the fuel tank or the shaft or the stuffing box, neatly changing the appearance of my right knuckles to purple swollen pulp, and breaking all fingernails below the quick. Note to self: add gloves to tool box!
Here is a picture of old stuffing material hanging out of the right side packing nut. The top of the picture is forward, and the white bilge pump can be seen below/left of the nut. I slid the nut up the shaft to this point for better access.
After all the old packing material was removed from the nut, I then used a child’s tooth brush and WD-40 to clean out the inside of the nut and the threads.
Next I cut the new packing material to the correct length using the razor blade, at a 45 degree angle so that the edges would overlap, by wrapping it around the short section of pipe that is the same diameter as the shaft that I had kept in the tool box just for this purpose. You don’t want to cut the material against your stainless steel shaft because the razor will cut the finish and cause it to rust.
Next, and crucial to getting the new material into the packing nut, I followed the advice of an experienced marine mechanic who knew that I was going to be doing this job: I hammered the packing material just a bit flatter so that it would easily slide into the nut, knowing that it would be compressed tight once the nut was tightened. This worked well and I installed 4 rings of packing material into the nut, alternating where each end of each piece of new packing material met at 12 o’clock and 6’o’clock so that no two gaps lined up. I tightened the nut down onto the threads with the chain ratchet after the first two pieces of packing material were installed, then backed the nut off and inserted the next two rings of packing material and retightened the nut until it did not leak. I used the 1/8” wooden dowels to push the material into the nut evenly when it became stubborn or difficult.
I then cranked the boat and put it in forward gear at low RPMs to test the nut. It did just fine and the nut was not hot to the touch after running for a while.
Then I cleaned up, put things away, and reported back to my neighbor's boat just in time for dessert. I finished just before 8PM, so it took about two hours. Now the special Stuffing Box Tool Box is stored next to the special Impeller Tool Box that has everything in it for that job!