Guests on board
Something else I thought about as a downside to these. When we have guests it is still as hard or harder to explain how to use these as it was a standard marine head. At least we don’t worry about people putting toilet paper into this one but having to explain that poo and pee go in separate holes and that you have to rinse or clean up after yourself every single time you use it seems to generate a lot of resistance. We now have people we would prefer not to visit us on our boat because of the mess they left behind on the composting head. At its messiest (oh shit I missed the hole) it is still a simple matter of a minute or so to wipe the mess down the open hole to the composting bin and spray with water and wipe down again and then maybe spray a disinfectant if needed. In regular use you just about never need to do this but guests that have different attitudes or lack of ability to use it as described can be a trial.
somebody on a forum was commenting about how they didn’t feel comfortable with a composting head due to if the boat every turned upside down that stuff could come out of it and make a mess.. I’m dubious as to the logic of this argument against a composting head but here is my answer to that as well as addressing someones concerns about the cost of the commercial units.
On mine it is bolted to the floor and the top part latches to the bottom that is bolted to the floor. There is a flap that secures the solid waste tank at the top. It is spring loaded and holds itself shut when your not using it. I don’t see the unit letting the compost fall out. Upside down there would be the possibility of the urine leaking back out. However if it was totally full that would be just at or over 2 gallons of urine no more. If it was that huge of a deal I could see how to modify our system to use a small tank for urine with a line running to it with a valve on it. However it would also call for all the plumbing of a normal holding tank to either pump the urine off the boat or discharge it overboard. Though more complex it would also allow with say a 10 gallon tank a pump out schedule or overboard outside the 3 mile limit of of say 20 to 25 day intervals for two people.
We installed the “Natures Head” composting toilet this past weekend. It fits perfectly side to side (read “it is a tight fit”) to get it in the head compartment you take the top section off the bottom section. This is just a matter of unclipping two clips, one on either side of the unit and then sliding the top section left 3 inches or so as you lift it up to disengage the rear hinge. At that point both pieces will easily fit through either of the head doors.
Here is a few picture of the two stainless angle pieces that hold the unit to the floor. The first shows how we marked where to set the mounts. We put the head in place and them made sure that we had room on either side for the crank to turn on the right without hitting the wall and the latch on the left side of the unit to open as well as being able to slide the top to the left when pulling it off the hinge when removing it. Once it was spaced right we took a pencil and just drew a line around the backside of the angle pieces to mark where they went.