Tuesday, November 10, 2009

Problems Solved, Sort Of

Vero Beach

It's a great feeling when one tackles a repair or maintenance problem and solves it completely and entirely. It is considerably less great to solve it partially and leaving open questions.

I wrote before that since installation of a no-drip kit on our propeller shaft stuffing box, that it has been leaking water. Three times, I tightened and/or repacked the stuffing box to no avail.

The other day I set out to track down the problem. It's not easy because I had mounted our muffler in a position that blocks all access to the stuffing box. Therefore, I had to remove the muffler just to see it up close. When I did I, and when I looked carefully, I found the problem. The stuffing box screws onto a threaded pipe. That pipe is joined to the shaft log with a short length of rubber hose. The four hose clamps on that rubber hose had rusted out and broken.

It all sounds technical I know, but perhaps the blueprint below makes it clearer. See the note about hose and hose clamps.

Anyhow, I replaced the hose clamps with brand new "All 316" clamps, which are the best quality available. I clamped them down tight and put everything back together. The problem is it still leaks. Oh no!

It did improve things. Before, it leaked about 2 quarts per hour. Now it leaks about 1 pint per day even when the engine is not running. So I solved 99% of the problem. But where is the other 1% coming from???!!! It's very frustrating. I can't really inspect it closer without taking the hose all the way off. If I do that with Tarwathie in the water, it will open the flood gate. Water could stream in. It could sink us if it came too fast. Even if we didn't sink, the stream would no doubt mask the small residual leak I have. If I do it out of the water, there is nothing to show the leak.

Aargh; frustration.

Argggh. I guess my tentative solution is to live with it the way it is.


  1. I wonder if when it was leaking so much if you got a buildup of something between the stuffing box and the hose or between the boat and the hose ?

    And now when you put the new clamps on it is holding the hose away from the other part and letting water in.

    Bill K

  2. Dick,

    You probably know all this, but just in case something might help, here's what I think I know about all this.

    My experience with the dripless seal is that it isn't. It is very difficult to get enough flax of the specified size into the stuffing box and still catch a thread to set it all in. Next time you might try a smaller sized flax and three rounds cut on the bias so that even the butt joint is longer than it would be otherwise. The joints should also be displaced by 180° around the shaft. When I install them, I put the packing nut on each round and push them into place individually. You do want it to leak, but not much, when it is running. You should not hurt yourself by touching the box while it is running. With the muffler right there, you might want to place a temp sensor on the far side of the stuffing box so you can the temp electronically without too much interference from the radiation of the muffler.

    BTW, I tossed out the dripless seal and went with the PSI system. It barely fit, but it works and is dripless; Parfait's engine sump is now dry.

    Good luck.



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