If you can’t point to something and say, “this is the problem,” when trying to fix something, the chances are pretty good that the something isn’t fixed.
And so it was with the head modification. The first configuration should have worked, did work, but did not seem to be working very well. So the configuration got changed. It also worked, seemed to work a little better, and was a decidedly more elegant solution to the hose runs than the first one had been. There is a certain amount of wisdom in the idea that, “If it looks right, it is right”. The new configuration certainly looked a lot more “right” than the old one. It was enough to stoke the hope that the problem had been solved. Still, the more thought that went into it, the less likely it seemed. This is a low pressure, low volume fluid system. The things that were changed were 99% cosmetic. From the point of view of fluid flowing through lines, the first configuration was as “right” as the second. Still, it had been a longish work day, the project had already taken two more days than planned, and yours truly was just getting tired of working on the boat. The system had worked before the modification, the new “look” was better than the old, and I really, really wanted the job to be done.
Ed Note: We did in fact get off the dock today and had a really nice sail in Tampa Bay. That's what that white thing is for... |
But 24 hours later it was clear that wishful thinking wasn’t enough to call a job finished. The system was still not working as well as it should. The main give-away was the amount of pressure that was building up at the diverter valve. A little bit of pressure was expected as it is at one end of the anti-syphon loop. Turn the valve and what fluid was in that half of the loop would flow into the holding tank. But, even after the configuration change, when the valve was turned, fluid was doing a soft kind of explosion into the holding tank. There was also more pressure on the flush pump handle than was usual. Clearly something was seriously restricting the flow somewhere, likely something we had disturbed during the mod. That didn’t help much since, during said mod, we had pretty much disturbed the entire black water / holding tank run from flush pump to thru hull.
There were several likely candidates. One was the diverter valve itself. During the work it was discovered that the valve had suffered an internal failure. One of the seals had torn and was partially jamming the thing. It had been completely disassembled, cleaned, all seals had been replaced with new, and the valve reassembled. Since it seemed impossible to put the bits back together wrong it wasn’t likely the home of the trouble. Still, it was easy to reach, another plus for the new configuration. Since the problem had not existed before we started, had existed after we finished, and the valve was the one thing that had been touched the most, it seemed the best place to start. Disassembly proved that it was, indeed, impossible to put it together wrong and that it was working exactly as it should.
The curved plastic tube at the top of the anti-syphon loop, the tube that holds the Micky-Moused little valve itself, was the next easiest place to reach. Since things tend to fall away from the top of something, there was faint hope that this would be the place to find “the fix”. On the other hand, if one skipped looking there, Mr. Murphy would suggest that was where one really needed to look. So we looked.
And found nothing to fix.
Least attractive and holding the most potential for disaster was something jammed up in or near the thru-hull. It was also the only place left where the trouble could lurk. So it was with some trepidation that the clamps were removed, the heat gun applied, and a sharp knife was taken to the hose attached to the thru-hull shut off valve. Mine wasn’t the only sigh of relief when the hose came free without water flooding into the boat. There was another sigh of relief when the valve was slowly opened and water did, indeed, flood into the boat. The hose itself? Ugly. And clogged. Clogged with sheets of calcified “stuff” clearly knocked free from the inside of the hoses as they were twisted and bent into various configurations. There was also a plain, old fashioned clog where it attached to the thru-hull, the inside diameter of the line less than half the original. Open enough that the pump still worked before we messed with the hoses. Blocked enough that the debris cascading down from the hoses being moved was enough to do it in.
Something that was clearly wrong that needed to be fixed. A new length of hose and some flushing of the thru-hull, and the head seemed (don't want to jinx it) to, once again, be working properly.
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