Composting toilet update

This will probably be the one and only update on the composting toilet.

I put the composting toilet into service as soon as I had the room ready. After a few days of use and continuing my work in the boat I started to notice an odor. I was working in the forward cabin, kneeling on the floor working on the valve that drains the gray water holding tank. I kept getting a nasty whiff of funk, and after not much investigating, I concluded the odor to be coming from the composting toilet. I kept down playing the funky smell, and telling myself this was the "earthy" smell these units put forth. After a few days of this, I put down my tools and said to myself " this isn't going to work for me". I started looking at the vent pipe, the filter in the outlet and inlet, and put my hand over the inlet to make sure the fan was working. My hands are beat up and calloused, so I really could not tell how much flow was coming out of vent. I decided to get the lighter I keep to light the wood stove and see how much air that fan was putting out of the vent. Holding the lighter by the vent outlet, I determined the flow rate was pretty lame, and for that matter, it appeared that the flow rate was zero. So I moved the lighter to the inlet side of of the inlet to see if I could witness how much air was being sucked in. I now was thinking that the unit was not sealed to well, and maybe the funky smelling vapors were leaking out past the gasket and not making it to the vent outlet. Putting the lighter up against the fan inlet, I was surprised when the lighter was blown out. I re lit the lighter, and damn if the same thing did not happen again... the flame was blown out. I had the fan installed backwards, and the unit was venting into the cabin. The composting toilet is designed to pull air in across the solid waste bin, then vent that air out of the cabin via a 1 1/2" vent line, and I had it working just the opposite.

Now that the unit is plumbed correctly, I'm happy to say it is working great. While the usage is light ( two" events" per day), the odor is non existent. There is a slight musty smell when the door is opened, but it is neither offensive nor strong. The unit is easy to operate, and more easy to keep clean. The draw on the battery I use to power the fan is extremely low. The only thing I will do different in the future is to use a more compost friendly type of paper. Paper designed to break down would greatly increase the capacity of the bin. The bin is nowhere near full, but it is obvious that the paper does not degrade as quickly as other material.

This type of toilet is probably not for every boater, but I'm going to have to claim this as a success. It's pretty stinking simple, and my first hand experience finds that it works exactly as designed. I doubt very much I'll go back to the old style toilets.

After reading these last posts, you're probably thinking I have too much time on my hand, so I'm going to change the subject "matter" now. My next post in a couple of weeks will show some progress in the guest cabins.

Here's a picture of the cabinet I built for above the toilet. The amount of storage in this boat is going to be nice.

Composting Toilet

As of press time, deciding the toilet type was one of the more thought provoking decisions made on the boat build to date. Every boat I've been involved with has had a macerating type toilet. Every boat owner I know has a macerating type toilet. Every boat owner in my neck of the woods whom I spoke with regarding composting toilets thought this to be a foolish idea ( I guess old habits are hard to dump). It is for all of the reasons I just stated, and a few ideas of my own, that I decide to utilize composting toilets on the trawler.

I'm not going to go into a ton of detail on this toilet, but I will say that it is a simple device that is well thought out in regard to use and maintenance. I was a little nervous about going this route, but after installing the unit and giving it the twice over evil eye, I'm feeling pretty confident that this composting toilet is going to make life on board more simple.

I went ahead and installed and finished the toilet area of the bathroom so I could have a working toilet while I build the boat. The toilet has a 12 volt fan built in to power air into the composting bin. The fan only pulls a few mill amps of current, so I decided to power it off of the circuit for the shower sump. I installed a simple set of 12 volt thumb screws in a wall box to make the connection to power the fan. This is a fast, simple connection that is reliable and looks pretty decent. Before I sheathed the walls, I installed a 1 1/2" PVC vent line to vent the composting bin. The vent line will eventually exit the front wall of the wheel house. After one drops a bomb in the composting bin, a stainless steel handle needs to be cranked a few times to mix the material in with the peat composting media. The handle can be used on either side of the unit, but since we are all right handed, I used the right side. Under normal conditions, the unit can handle about 80 events ( gotta love being politically correct while trying to talk about defecating). The science behind this is simple: keep the solids and liquid separate, keep oxygen moving in all the right places, good ventilation and moist composting media. This thing will work.

I'm pretty much sold on this idea, but I still installed a 1 1/2" schedule 40 PVC transport line from the bathroom to the main holding tank of the boat. Getting that line installed was a pretty simple thing, and because I used rigid PVC, the line will last as long as I'm on this world. If the composting toilet fails, I got a huge piece of infrastructure in place to use a different style head.

I read every post on every boat cruising forum I could find regarding composting toilets. I could not find one negative thing written about this style toilet. All post I've read by hard core cruisers and live a boards all agree that those who switch to this style head do not switch back to the macerating, vacuum, or manual style heads along with the associated holding tanks. A large part of my excavating business is installing septic systems form homes, and I'm pretty happy that I won't have the mini version of a septic tank on the boat. I now have two gray water tanks for a total capacity of 135 gallons, and 8 fresh water tanks for a total capacity of 360 gallons. It feels good knowing that none of the precious fresh water will be needed for flushing.

As the hour meter starts to tick and time begins to accumulate on the composting toilet, I'll start giving some updates on the performance. A few of you out there might be thinking that I'm jumping the gun by getting a working toilet on board at this stage in the game, but the truth is that I'm psyched to have another place to sit and ponder.

Guest cabin dressing room update #2

The last few weeks have found me getting the Carver boat ready for it's new owner so not much has been getting done on the boat build. Now that the carver is finished and out of the shop, I'm back working on the boat build.

I received the new sink so I was able to complete the installation of the top, the sink, and the faucet. All the cabin plumbing connections are now complete. If I had the pressure pump and a couple of days work, I'd be able to use the sinks.

I installed a new valve for the through hull fitting under the guest cabin sink. The valve I had originally installed was a cheap gate valve that was probably doomed for failure. I installed a more corrosion resistant ball valve in place of the gate valve and hopefully saved myself a future headache. I had read on another forum that gate valves have no place on boats, and I agree.

The through hull fitting under this sink is the only through hull fitting for the cabins sinks and shower. This through hull fitting is a stainless steel piece of pipe, welded in to the hull that is threaded on the inboard end. The ball valve threads on to the pipe, and that is my basic through hull fitting. If gray water needs to be held, the red handled ball valve is shut, the black handled ball valve is opened, and the sump pump selector valve is moved to the holding tank position, then all the gray water goes to the holding tank. If we can discharge gray water, the red handled ball valve is opened, the black handled ball valve is closed, and the sump selector valve is moved to the discharge position so all gray water is either pumped or gravity flow overboard.

The galley sink, the clothes washing machine, and the half bath above will have another holding tank and one through hull fitting to deal with that gray water.