It's a weird thing to say but I am pretty proud of my toilet. After tons of research on composting toilets, we settled on making our own. In the beginning of our conversion process there was no question, we were going to buy a Nature's Head composting toilet. They have a great reputation, a lot of skoolies have one. Then I saw a video about the Airhead composting toilet and I was really digging that one, even more than the Nature's Head. Once I realized there was more than one option for composting toilets in a skoolie I started to dive even deeper in the the world of composting or dry toilets. You see, a toilet like this in a skoolie or RV doesn't actually provide you with compost, that process takes a while. What a "composting" toilet does is provide a start to the composting process and by adding carbon rich material like coconut coir or sawdust you are helping the process of decomposition. By separating the urine you are helping the process even further and reducing the chances of yucky smells.
I took a good look at the Nature's Head and Airhead toilets and made a list of the key components. They both had a container for number two and another container for urine. There was a separator to keep the urine out of the poo bin, it kinda was like a funnel, kinda. They each had a fan to vent to the outside. Then there was the obvious things every toilet needs, a base and seat. Both the Airhead and Nature's Head also have a means to stir the poo and coconut coir too but I after a bit of reading and seeing some other homemade toilets I deemed that less important than the elements listed above. So basically all I had to do was duplicate what would normally cost around $1000 for less because at this point in our build we are beginning to pinch pennies. There are a lot of things left to do and buy and the funds are starting to dry up. We definitely underestimated some costs but if we are frugal we should still come in around budget (fingers crossed). This had a bunch to do with the decision to make our toilet, I figured I could do it for around $100.
I started with a sketch, it was kinda based on another toilet I saw while searching diy composting toilets (see photo above). I figured if I could get the poo bucket and pee container I could just design the base around those and pop a seat on top. It was almost that simple except finding a urine container was harder than one might think and I didn't want to cough up $45 to Airhead for one of theirs. What I settled on was a two gallon gas can from Walmart for $11. A lot of the homemade toilets out there just use a one gallon milk jug but I will have five people peeing in that thing and I don't want to empty it every two hours. Fun Fact: The normal range of urine output is 800 to 2,000 milliliters per day per person if you have a normal fluid intake. There is 3785.41 millimeters in a gallon for those of you who don't want to math. A two gallon jug might need to be emptied every couple of days and I'm as ok with that as I'm going to get. The poo bucket is just a trimmed down five gallon bucket I already had in the yard but if you had to purchase one they are $3.50 at Lowes. So, I got to building.
I took the two vessels and placed them next to each other and made a template. I made the back flat so it would sit flush to the wall and rounded the front. I could not make it as rounded as my inspiration photo because of the shape of the gas can. When making the template and creating the shape of the toilet I was also trying to keep in mind the size of the Nature's Head because we had already framed in the bathroom on the bus and I didn't want to have to change anything there. So I made my toilet roughly the size of a Nature's Head.
I took the template of the bottom and cut the bottom of the toilet with scrap plywood. I used the same template and made a top out of some scrap butcher block from the counter-top, the toilet seat would sit on that. I cut some scrap 3/4" ply for the back and sides, I made several pieces so that I could match the shape better. I glued and screwed it all together and painted it with Kilz. I then covered it with a piece of corrugated metal that I bought at Lowes for $19. This made the base of the toilet. I purchased a toilet seat from Walmart for $24. and a urine separator for $45. from a company from the UK called Free Range Designs. (You should totally check them out because the furniture they make is bananas!) These two items allowed me to finish the top of the toilet. I mapped out where to cut the hole in the top with the inner hole in the toilet seat ensuring that the urine separator was in the optimal location in relevance to the urine container, a hose connects the two. I cut the hole and sanded the top and painted the whole thing with Kilz because it was what I already had sitting around. I mounted the urine separator to the inside of the top and popped it on the base. Hey, I made a toilet!
Well, almost, I needed to find a way to attach the hose for the fan and vent. In a completely unrelated Amazon search for some other bus stuff I saw this thingy for a marine battery box that was perfect. It had a hose, a vent, and a hose attachment thing. It was indescriptly called MTS Company 274 Hose Vent, what?! Anyway it was $19. I also bought a little fan which is exactly the same fan Airhead uses in their toilets for $14. The hose was exactly the right length and the whole set came with a vent that I will use on the outside of the bus once I install the fan and cut the hole in the bus. The set was made for homemade composting toilets and I think the manufacture should revisit the product name.
So I made a composting toilet! If you are good at math you already added it up and realized I went over my estimate of $100. The whole thing cost me $132. to build. Only time will tell if it will work out but I think it was worth the gamble if it potentially saves us over $800. Some other skoolies who have made their own composting toilets have nothing but good things to say so I am hopeful. I am also really proud of myself and excited to be back into building and creating with my hands again. For many years I worked as a sign artist for a grocery chain and got to create, build, and draw everyday. My work as a doula is fulfilling in a different way but getting back into using my hands to create is so awesome!
Here are some photos of the whole process:
Note: I am not a professional toilet builder, skoolie builder, or humanure expert. This is what I did and what seems to work so we are going for it.