Wednesday, July 3, 2013

Backing up

I didn’t mention one of my major activities while we were anchored in False Creek with Mike & Diane but, unpleasant as it was, it nevertheless bears reporting.  Those of you who are fortunate enough not to have to deal with marine sanitation may wish to skip this rather messy story. 

First off I don’t know why the hell we can’t just call it a shitter or a bathroom.  Somewhere in the murky depths of history some fool decided to call a boat’s kitchen a galley and the bathroom a head.  I don’t claim to know why but I have succumbed to tradition and will refer to the crapper as the head.

The first morning in False Creek the head in the master stateroom failed to flush.  It didn’t overflow but it would have if I had kept on pumping.  The way our heads work is they have a bowl just like your home crapper but underneath that bowl there is an adapter housing for a macerator pump.  So in theory the crap falls directly into the macerator and gets pumped to the holding tank.  The complication is that we don’t have a water tank above the toilet like you do in the house.  And we don’t use pressurized fresh water like an RV does either.  Incorporated into the macerator pump is a totally separate impeller which draws seawater into the bowl and that is what accomplishes the flush.  The problem with that arrangement is that when the outflow gets plugged the inflow continues whenever you try to pump out.  The solution is to reach under the counter and shut off the inlet water so its not an insurmountable problem, just an annoying one.  And of course when the water level in the bowl is slowly rising you keep thinking that any minute now it will clear the plug and the level will start dropping, as it usually does.


Marine heads also incorporate the option of pumping directly overboard or to the holding tank.  They do that by means of a 3-way or “Y” valve that sits directly after the outlet of the macerator.  From that “Y” valve one leg goes directly overboard and one goes to the holding tank.  So my first reaction was to try to pump the contents of the bowl overboard.  No go.  The combination of not being able to pump in either direction led me down the wrong troubleshooting path and caused me to focus on the pump.  It seemed logical that if I couldn’t pump anywhere then I was dealing with a defective pump rather than a plugged line.  Even after I figured out that the line to the holding tank was in fact plugged I still had a residual thought that there must also be something wrong with the pump. 

After a long and unpleasant day of troubleshooting it transpired that both lines were in fact plugged and there was nothing whatsoever wrong with the original pump.  Of course by that time I had replaced the pump, and in fact the entire toilet assembly (with no change in the ability to pump out.)  In the process I learned a lot more about marine sanitation than I ever cared to know.  It turns out that there is a reaction between piss and seawater that hastens the formation of some kind of calcium salt inside the hoses.  Both my overboard and holding tank hoses were in fact full of these salts.  The salts are porous enough that they will pass small volumes of liquid but of course eventually get jammed up with solids.  They are also porous enough that a toilet snake can pass cleanly through them and no mater how many times you pull it in an out they will remain stubbornly in place.  Of course Mike and I only learned this after the snake that I had onboard broke and we made a trip to Home Depot to replace it.

The solution is acid.  If you catch it early enough plain old white vinegar is a strong enough acid to keep the lines clean.  Going forward a regular (monthly) dose of vinegar will be on our maintenance schedule.  In emergency situations such as I was facing muriatic acid is required.  Fortunately I had some onboard.  I now have more in stock and the next time I get to a hardware store I will likely add a couple more bottles to my inventory.  Its really miraculous how quickly it cleans up the lines but it did take quite a bit of acid to clean the line to the holding tank because its close to 30 feet long.  That much sulphuric acid in the tank of course also caused a steady release of sulphur dioxide over the course of the next few days.

We’re roughly a week past the initial incident and I think we have the problem in hand now.  In the process I learned a lot and we got a new crapper in the master head.  I guess its not all bad.  The new crapper is a bit bigger – perhaps more comfortable although that seems a foolish consideration.   

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