What would Ben Franklin do?
It was back in November that Rebecca and I first started considering changing the toilet in our boat from a traditional MSD (marine sanitation device) to a composting head. Having since done a LOT more reading on the subject, we are now at the point where we are SERIOUSLY considering it. One major issue that we had to deal with is “will it actually fit on the boat?” I have been in contact with both the manufacturer and the Canadian distributor for Nature’s Head. Both have been very helpful, answering my email questions and offering to call me to speak to me on the phone. Yesterday we braved the freezing cold temps to go to the boat to take some measurements. Will it fit? It will be close! The distributor offered to send us one and if it doesn’t fit we can just return it.
To make the ultimate decision of whether to change to this new system we employed the famous Ben Franklin Decision Making Process. Google that phrase if you are not sure what I am talking about.
“My way is to divide half a sheet of paper by a line into two columns; writing over the one Pro and over the other Con. Then during three or four days’ consideration, I put down under the different heads short hints of the different motives, that at different time occur to me, for or against the measure. When I have thus got them altogether in one view, I endeavor to estimate their respective weights; and where I find two, one on each side, that seem equal, I strike them both out. If I judge some two reasons con equal to some three reasons pro, I strike out five; and thus proceeding, I find where the balance lies; and if after a day or two of further consideration, nothing new that is of importance occurs on either side, I come to a determination accordingly.” –Benjamin Franklin
Here is what we came up with on the Pros side:
- changing will free up through hulls (holes in boat) which could be retasked to the yet-to-be-purchased watermaker
- the new system can’t clog
- no need to carry expensive rebuild kits for seals, pumps, etc.
- much lighter as there will be no full holding tank in the bow of the boat
- no need to find pump-out stations
For the Cons:
- Number one is money. The new head will be just under a grand.
- New system requires electricity (although a miniscule amount, this needed to be listed)
- Liquid waste (which is basically sterile) needs to be disposed of every 3 days or so
- We will need to carry a supply of peat moss or coir
- It is a “different” system to get used to (the other head requires its own system too, but we are already accustomed to that).
- We need to install it (the other one is already there and working)
Obviously those pros and cons are not equal. Rebecca felt that having to install the new head would be a deal-breaker given my limited handyman skills. I am pretty confident I am up to the task though. The $1000.00 is a biggy of course, but the stupid rebuild kits for the old one are almost a hundred bucks. So that would add up quickly. All said, unless something radical occurs in the next day or so, I think we will end up making the shift, or at least attempting to. We’ll see what happens.
We have now had our home brew composting head running for almost a year of full time live-aboard and the bottom line is it works.
As for the nitty gritty…
1. Odor is not a problem.
2. We are using popcorn and peat moss as our composting mediums it would appear that a $6 bag of peat moss from Ace Hardware will apparently last us for a couple of years.
3.Our solids container a five gallon bucket and (the Airhead & Natures Head also is 5 gallons as I recall) seems good for two people for two months.
4. Our liquid container (2 1/2 gallon) on the other hand needs to be emptied every couple of days which is a bit of a pain but not really problematic. We have added a second container to make it easier to sync into our schedule. Both bottles have screw tops so if needed taking them to be emptied in a local marina toilet is a no muss no fuss affair. For passages and where legal it is simple to just pour the liquid overboard.
5. the total cost of our home built head was about $120 which breaks down to …
A. bucket…$3..
B. small computer fan 12V $9.
C. Liquid containers were free as it is how our kitty litter is purchased. Finding the right container was somewhat problematic as finding a container that fit in the space was more difficult than expected.
D. We bought the Privy kit from Ecovita (http://ecovita.net/privy.html) for $112. as it seemed simpler than making my own urine/solids separating seat.
Our install is very similar to the “Baja box” plans available here… http://ecovita.net/news/wp-content/uploads/2009/07/PrivyKit-Baja-Box-Directions.pdf
Thanks for the detailed comments RLW. That is certainly a LOT cheaper than buying a ready-made unit. Do you have any pics online of the completed install on your boat?
A big factor in deciding for me would be the smell. That distinctive ‘not a real toilet’ smell. Growing up traveling the states in a motor home, I think I can smell the non-composting toilet a mile away. And the mess of that blue goo you have to put in them. I have memories of my dad getting that stuff on him every time he had to do anything with the toilet. If the composting toilet didn’t have that smell I’d be sold.
Every report that I have read says that a properly maintained composting head does not smell at all.
I think the key to having it not stink is the air flow. In land dwellings, they use a pipe out the roof. However, as we walk around on the roofs of our houses—-! I think the newer designs, like the Airhead and Nature’s whatever, don’t stink because of the separation of urine and solids, so they don’t need the air pipe. Not sure about this, as I haven’t read instalation instructions.
They definitely are vented, and require either a solar vent or a computer muffin fan for this air flow. If you visit their websites you can see how that is organized. The separation of the liquids and solids is the key though, as I understand it.
@Helen A. Spalding: We have a Natures Head, and it does have a vent. Ours is routed to the old MSD pump out hole.
Good ventilation is indeed a key to a stinkless system, and ours is being handled by a solar powered fan that creates a great airflow from the holding area to the outside world. With the Natures Head, it does have an inline 12 VDC fan that you can leverage too.