Composting Toilets

[Ocean Girl]

This seems more art than science.

We are going to try composting head aboard Rain Dog. First we will rip out the one year old head and hose and just get a porta Loo and separate the 1 from the 2, play with the saw dust or coir stuff, just to see how primitive we can go. Maybe rig a vent from the top of the bucket to the outside( screened). If it is as simple and straightforward as it seem then we will either build a custom head or see if a C Head will fit. We have a very small and narrow footprint for the head space so custom is probably what we will end up with.

We will save the head just in case we decide it's not for us, and replace all the hoses, etc.

My question and major concern is bug infestation. Bugs seem to be a problem in the tropics for composting heads, and we are and will be cruising the tropics.

I read about RebelHearts ordeal, anyone else have an issue to the point of switching back to a wet system?

Thanks for any input.
Ocean girl

[hummingway]

I've been using less and less desiccant but I'm not living aboard so the composted material gets pretty broken down between usage. The bugs seem to some from the desiccant so it makes sense that something like coir should have less.

If you are making your own consider this: if you have a second container for the feces and can rotate every two weeks the feces will be very well broken down. I use my boat a lot, sometimes for a weekend sometimes for a couple of weeks at a spell. Usually it's just me but sometimes a guest or two. I emptied it on the weekend because I'd been out for two weeks, two weeks prior, and am going out for two weeks again on Monday. It was the first time I'd emptied it since early fall despite using it quite a lot and I didn't absolutely need to empty. It is amazing how it breaks down into a small amount of matter that essentially smells of the forest floor. The major bulk seems to be paper!

With two of you full time of course it changes but if a person were able to work out having two containers so one could sit two weeks it would really help the experience. As for the bugs it seems that if the buckets are well sealed, with venting screened and a desiccant that doesn't host bugs you should be alright.

If you do go the composter route I can't stress enough that urine has to be kept separate. Men need to sit no matter how good they think their aim and woman need to sit so they hit the holes to the urine container. If urine mixes with the feces you will be wondering why we all claim no smell and when you empty the bucket it is very unpleasant and heavy.

[LauderBoy]

That's one of the nice designs with the nature's head. When the solids chute is closed, the "lid" that closes it acts to funnel the liquid into the front container. It helps keeps things separate.

I recently switched from Walmart compost to coir and started in on having insects again. Using raid cleared it right back up though. The coir is a lot more convenient to keep around but a little more effort to prep and it costs a bit more.

[Duke 48]

I could not find any "marine" composting toilets that would fit the space available on our boat, so I built my own. My wife calls it the Pooh-Pipe. It does not have the capacity of the advertised composting toilets, but I think it will work for us. Time will tell.

[audeojude]

We had gnat issues last summer and it was annoying but a few shots of bug spray into the head slowed them down. We then purchased a product that you hang in closets or garages etc that kills flying pests. It is labeled that you not use it if you are living there but we figured the head doesn't exchange air into the boat. So tried it anyways. Seemed to work. Purchased it at home depot in the pesticides section of the store.

We didn't add anything back the next change of compost and so far haven't had an issue since. I think it is definately something you should expect to face at one time or another in your use of these heads. The natures head doesn't seal totally. there is a little room around the forward edge of the trap door that opens into the body and I think that there is also airways from there that go to the Urine holes also. the fan pulling air through keeps all odor out but I think gnats could get through there to infest the compost. That being said we have been using it for two years now and only had gnat issues for about a month and a half of that. A shot of raid into the head once in a while just about totally suppressed them. To really clean them out you need to clean the head inside and out factory clean and get them out of the boat also. We just suppressed them till they didn't come back. Your millage may vary depending on how you try and fight them.

[audeojude]

Originally Posted by Duke 48

I could not find any "marine" composting toilets that would fit the space available on our boat, so I built my own. My wife calls it the Pooh-Pipe. It does not have the capacity of the advertised composting toilets, but I think it will work for us. Time will tell.

I think that is awesome.

In looking at it though I see that you have a lot of rough surfaces inside it. I think that you will find that urine and fecal matter will get into every pore and crevice and be very hard to clean. I would suggest polishing those areas up a bit more and get a everything smooth and non porous. so that what goes in can be flushed down the tube easily or that the fecal portion can be easily wiped down when someone inevitably misses.

We have a one quart or so spray bottle of plain water that we rinse the urine portion of our natures head with every single use. It puts very little water in the holding tank and so far has worked great to keep it clean and odor free on the urine section.

As for the composting part, once you have used it a while you good at doing your buisness into the bin without touching the opening. No clean up needed 5 out of 6 times. Just throw the toilet paper in on top of the poo and close the trap door and turn the mixing handle fully around 4 or 5 times. If you do get a stain we just spray it off with the spray bottle and then wipe the bowl or opening clean as needed. Disinfect as needed. The rotomolded plastic of the natures head is so slick it's kinda like using a teflon skillet. Nothing really sticks to it.

I would never use any abrasive cloth/pad/cleaner ever on the rotomolded units. As soon as you scratch the surface it will start to cling to fecal matter and urine much harder and be that much harder to clean in the future.

Just some idle thoughts after a couple years of use.

[audeojude]

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 **** 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.

On the flip side I had plenty of people like that on my "****:" list for messing up my standard marine head by improper use. At least now I don't have to take shitty plumbing/pumps/hoses apart or rebuild any of it on a semi regular basis.

Both then and now if your a guest you need to sit to do your business if you aren't willing to then you better take your business with you and not share it with us. We have a very low threshold for those that want to stand and urinate. As used the head is always immaculate and odor free. If you treat it like a house toilet it will start to smell like a house toilet with urine spattered around it on the seat, the outside of the unit, the head walls etc.

right now for the last couple months we have been spending about 3 to 4 days a week on the boat again and the last time we changed the coir was 9 or 10 months ago. We keep talking about doing it as it is time but we have no odor and the stir rod is still fairly easy to turn so every week or two I dump a single cup of extra coir into it and we just keep using it.

Our standard marine heads cost us on average 120 dollars a year to use between rebuild kits or hoses that needed replacing, chemicals for the holding tank, pumpouts etc.. The composting head once installed I think we have spent about 60 bucks for enough coir for 2 to 2.5 years and maybe 20 bucks on a can of raid and one of the flying insect killer things. This gives us a rough 30 to 40 dollars a year operating cost. Oh and the cost of a trash bag every 6 weeks to 6 months depending on how much we are on the boat to dump the head into when we change it out.

The only maintenance I have done to the unit is that I upgraded the stir rod to a more robust model the manufacture came out with. Not that the old one didn't work but the new one had a lower profile turn handle that was easier to use. We dumped the head and washed it out and put the new stir rod in. Total time taken was about 20 minutes from pull it out of the boat to put it back in the boat. No grossness, no odor. When we dumped it pretty much everything fell out the only stuff that stuck was on the stainless stir rod and a hose spraying it out got rid of that in a minute or so.

I hope that my ramblings help someone out just some of our thoughts on our Natures Head after a couple years.

[Duke 48]

Originally Posted by audeojude

In looking at it though I see that you have a lot of rough surfaces inside it. I think that you will find that urine and fecal matter will get into every pore and crevice and be very hard to clean. I would suggest polishing those areas up a bit more and get a everything smooth and non porous. so that what goes in can be flushed down the tube easily or that the fecal portion can be easily wiped down when someone inevitably misses.

I agree there is room for improvement, and per your recommendation, I will do some polishing. Fortunately, the entire seat assembly, including the separator, is easily removed for cleaning.

To minimize the possibility of developing insect issues, the bottom of the seat lid has a gasket surrounding the entire perimeter and the vent lines have screens installed.

After I have some experience with this system, I will probably build another unit with added improvements. I am already working on a system that will allow me to empty the compost compartment without having to pick it up to dump it.

[audeojude]

I have to say that your design is very ingenious. What size tube do you have on the bottom? I got to thinking that as the diameter goes up volume increases quite rapidly. What diameter PVC pipe do you think you could fit in your space?

[Duke 48]

The bottom is a 6" PVC T with screw in clean out plugs added to the ends. If needed, the bottom section can be disassembled. I might add, the stirring rods are reinforced with wood dowels.

[boatsail]

I just ordered the c head a few days ago. Cant wait to rip out the holding tank in the boat I just bought. We are trying to refit this thing as fast as possible and still get all of the use out of it this season without having it ripped appart all the time. I'll post once it comes in. Going to make a website to detail everything about the boat before and after the refit an add sailing photos and video too. It's a project(website) that I'm really looking forward to.

[hummingway]

Originally Posted by boatsail

I just ordered the c head a few days ago. Cant wait to rip out the holding tank in the boat I just bought. We are trying to refit this thing as fast as possible and still get all of the use out of it this season without having it ripped appart all the time. I'll post once it comes in. Going to make a website to detail everything about the boat before and after the refit an add sailing photos and video too. It's a project(website) that I'm really looking forward to.

One of the great thing about getting rid of the black water system is the space you get! My water maker pumps into a small tank that I can pump to my main tank or use directly. It all lives where the septic system came out. I have no idea where I would have put it if I'd kept the wet toilet. I can't say removing it was one of the more enjoyable things I've done but while doing it you can take great comfort in knowing you won't have to do it again!

[Watercolor]

The material is polypropylene. It absorbs little or no H2O so it shouldn't smell.

Note: if your system has any nylon fittings they will adsorb a lot of water (nylon is hydroscopic) and will transmit smells. My guess is that airhead, etc. composting systems don't have nylon parts.

[Knapweed]

After a lot of deliberation, we bought an Air Head last week. The through hull blocked with limescale and urea build up that fell away from the hoses and the holding tank leaked with the back pressure. It wasn't pleasant.

We also dumped the Paloma time bomb in the head and intend to replace it with an Isotemp 8 gallon unit, which runs off shore power or the motor/dickinson heater, in the space the holding tank currently occupies.

The amount of space this substitution frees up is remarkable. We will have to redesign the head a tad but it will now be easy to install a fore and aft unit with a lot more cupboard space. It also means we can lose two through-hulls and yards of hose, which can't be bad.

We are looking forward to reaping all the benefits discussed in this thread.

[Ocean Girl]

Yes this has been a great thread. I am on the fence between this or installing a waste treatment system for direct overboard.

But what looks simple may be more complicated and what looks complicated may be more simple .

Does anyone line their compost toilet bin? I found these bags that speed compost with impregnated gauze inside the bag. They use them in third world countries,trying to see if I can utilize this. Peepoobags.com

We got any marine biologists or microbiologist in here? Maybe I need to give one of my friends a call and see what they say, now...how to broach the subject

Cheers
Ocean Girl