Monday, January 01, 2007

Finally, a Problem Fixed

Vero Beach

About a year ago our head (toilet) started leaking clean salt water. The head has a lever to operate a piston for flushing, and a foot pedal to step on to admit salt water for flushing. The first year we were on Tarwathie it worked fine. Then a year ago it started letting in salt water even when not stepping on the pedal.

The problem is quite serious because the head is below the water line. If the leak had started when we were away from the boat it could have sunk her. It would let water in continuously, overflow the head into the bilge, and the bilge pump would pump it out until the battery was drained. That's why when leaving the boat we always close the sea cocks. Every thru-hull fitting has a sea cock.

Fortuantely, there is another shutoff butterfly valve for the head, positioned near the floor behind the head. (Yes there are three valves, the sea cock, the butterfly valve, and the foot pedal valve. We were able to open and close this every time we used the toilet in lieu of the foot pedal working. However it was unpleasant for us and even more unpleasant for all guests we had on board in the past year. My apologies to all guests who had to put up with it.

I tried to fix it several times before. For each try I have to take the head apart and carry it up to the cockpit where I can see it in daylight. It weighs almost 100 pounds so the job was difficult. Thank God the design of our head is such that I could do that without having to touch black water. It is a Wilcox and Crittenden Skipper head, very expensive, but very solid and well designed.

Well designed or not, I had no success in fixing the leak. There is a rubber valve that controls the salt water. It has two rubber flappers with metal buttons riveted into the center of each. There are two metal fingers attached to the foot pedal that push on the metal buttons.

My first attempt was to remove sald and/or lime scale from everything. No effect. Then I replaced the valve with a new one. No effect. Then, because the valve appears symmetrical, it can be inserted in any of four orientations. I tried all four. No effect.

Today, I tried once again. I took it apart once again and just stared at the mechnism. I worked the pedal back and forth many times. I tried to build up a 3D mental model of how the valve worked. I'm not good at that. Even though I'm an engineer by training, I'm not a mechanical engineer. I've always had trouble seeing the relationship between the function of gadgets and their shape. Even things I helped design I had trouble recognizing when I see them. This time however, I just kept at it long enough to finally succeed.

I decided that the metal fingers weren't pushing on the buttons hard enough when the foot pedal was released. I cleaned them off with a wire brush, then I applied a dab of J-B Weld to the end of each making them about 3mm longer. I let the J-B Weld (the quick formula) dry for a couple of hours and put it all back together. Success! The seal appears to be tight. We can go back to using just the foot pedal and forget the butterfly valve. Hooray!

I should also thank J-B Weld. It is the most remarkable product. Over the years I've used it to repair many things. I don't know if they sell it outside the USA. I think every handyman should have J-B Weld in his/her toolbox.

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