Documentation to reproduce a composting marine toilet that is the same height as a standard Jabsco type III.
This urine diverting composting toilet was designed to replace the type III originally installed by the boat manufacturer. There is no commercial composting toilet available that would fit because of the height. The shortest one I could find is a C-Head 'Shorty' model and it is too tall.
All components are off-the-shelf except for the urine diverter. This component was 3-D printed on a 200 x 200 mm print bed in 5 parts and glued together. The solid container is a standard 2 gallon unmodified paint bucket from HomeDepot. The liquid container is an unmodified small size bleach bottle. The enclosure is 1/2 inch birch plywood, glued and screwed and coated with a layer of polyester resin. It is painted with Rust-oleum enamel.
Normally, I line the bucket with a small plastic trash bag and take it immediately off the boat when a trash can is available. Otherwise, I would actually start the composting process in place and empty it when I can. The liquid bottle has to be changed about once per day for one person and proportionally more often for more people.
Comments, corrections, and suggestions are welcome.