Composting Toilets

[Bloodhound]

Our head is aligned fore and aft so tacking has no effect on urine drainage into the right receptacle. I can see the problem though if the urine and feces end up in the same pot, COIR or no COIR. Things just get too wet and you revert to an aerobic digester (or anaerobic, if there's no air flow). The only solution is either to withhold deposits until on the right tack or turn the head 90 degrees so solids are really separated from liquids regardless of heel angle.

This may also be a design issue with the head itself. Perhaps the designer should consider a much steeper slope towards the liquid outlet holes so the reasonable heel angle (say 20 degrees) doesn't compromise the functionality. Ours is fairly gently sloped as well and Im sure it would be problem for us too if the head were aligned other than fore-aft.

[rebel heart]

I'm not too worried about it, but yeah, it seems like the kind of thing that someone should have engineered around by now. Considering how little times boats spend underway (and then slice that in half because of it being on one tack versus another, then slice again by enough heel angle to cause the problem), I can see why this might have evaded a design change.

What I loved about it though was that fixing the "smelly head" took me about 10 minutes, was relatively painless, and the problem is completely solved. Compare that to troubleshooting the smell from a wet system which involves 25' of plumbing, a dozen couplings and clamps, tanks, vents, vent lines, anti-suctions, etc.

[hummingway]

Originally Posted by rebel heart

I'm not too worried about it, but yeah, it seems like the kind of thing that someone should have engineered around by now. Considering how little times boats spend underway (and then slice that in half because of it being on one tack versus another, then slice again by enough heel angle to cause the problem), I can see why this might have evaded a design change.

What I loved about it though was that fixing the "smelly head" took me about 10 minutes, was relatively painless, and the problem is completely solved. Compare that to troubleshooting the smell from a wet system which involves 25' of plumbing, a dozen couplings and clamps, tanks, vents, vent lines, anti-suctions, etc.

The urine thing unlike getting the mix to wet can't be fixed by putting more dessicant in, though it does help, so you were wise to empty it. I've occasionly overflowed the urine tank and had it run back in. Lots of dessicant makes it better but doesn't keep it from smelling.

It's been about a year now since I put mine in. Now that I'm not living aboard I can really see how well it works. Two of us used it for two weeks about a month ago. I used it today and there was almost nothing in it.

[Wand]

Originally Posted by hummingway

It's been about a year now since I put mine in. Now that I'm not living aboard I can really see how well it works. Two of us used it for two weeks about a month ago. I used it today and there was almost nothing in it.

That seems to be a developing trend of thought in this thread - that composting toilets are excellent for cruises on inland waters or other non-dumping zones of a few weeks duration followed by a longish period of no use. You then have a product that is both useful and safe to handle. But that the toilets are problematic for liveaboards or other arrangements involving continuous use because the dumping of product including ripe excreta is inevitable (or finding a place to put it aside for some months if rotating buckets). Is that a reasonable summary?

BTW Hummingway, did you keep the fan running while you were away from the boat?

[Bloodhound]

The fan must be allowed to run 24/7 because the feces are being decomposed aerobically (with air) so a small air flow is essential. A muffin fan draws milliamps, so no big deal

[Greggegner]

We have a Nature's Head and like it. If you can't find a place to dispose of the waste then you will have an issue getting your holding tank pumped. Urine is sterile. Getting ride of it posses no problem to the environment. If possible use a public rest room, if not dump it. Solid waste, if the composting head gets full dumping it with mostly decomposed waste is better than pumping your head overboard.

[rebel heart]

For the fan we have a solar day/night fan set to exhaust; seems to work fine. And although it's not perfectly composted, I'll take emptying a partially composted head from us living aboard over a pumpout any day. Cleaner, easier, much less frequent.

There's nothing especially bad about tossing partially composted crap in a bag into a dumpster. I'm tossing my four month old's completely uncomposted crap filled disposable diapers in a dumpster.

[hummingway]

Originally Posted by At sea

That seems to be a developing trend of thought in this thread - that composting toilets are excellent for cruises on inland waters or other non-dumping zones of a few weeks duration followed by a longish period of no use. You then have a product that is both useful and safe to handle. But that the toilets are problematic for liveaboards or other arrangements involving continuous use because the dumping of product including ripe excreta is inevitable (or finding a place to put it aside for some months if rotating buckets). Is that a reasonable summary?

BTW Hummingway, did you keep the fan running while you were away from the boat?

I don't. Plenty of air gets to it anyway.

I liked using it when I lived aboard but most of the time it was just me and didn't require emptying to often. I found it preferable to a tank and flush toilet.. I think ideally having a second waste container and rotating them would be the answer.

[Wand]

Originally Posted by hummingway

I don't. Plenty of air gets to it anyway.

Thanks, that's interesting. So you turned it and power ventilated it while aboard but then relied on natural ventilation with no turning for the next month - and it did it all by itself. Maybe you might be tempted then to experiment without the fan at all? The findings sure would interest me, if you're game

[Doodles]

Originally Posted by At sea

Thanks, that's interesting. So you turned it and power ventilated it while aboard but then relied on natural ventilation with no turning for the next month - and it did it all by itself. Maybe you might be tempted then to experiment without the fan at all? The findings sure would interest me, if you're game

I'm very interested in this as well. Currently, I have an Air Head installed but have not hooked up a fan yet. We've been tied to the dock and have just used the toilet for peeing. There is a little odor sometimes but we put a small chunk of deodorizing block (the stuff they put in public urinals) in the top where the urine drains into the bottle and no more odor. I hate to cut the hole in the deck for the fan and since someone else earlier (this thread or another ??) mentioned they had made a temporary composting toilet at a house they were renovating and used no venting fan and it worked fine, I've been curious as to whether I could get by without one.

[aquarian]

Thanks for the info guys/gals. I have been interested in these for a while. Now I'm very interested. I will be trying it on my next boat.

[hummingway]

I run the fan while the excrement is fresh. Once it has broken down somewhat it isn't required anymore. The real reason for the fan is to keep the smell going out the boat and since it does smell when you are using it everyday you need the fan going, in my experience anyway. Once it has broken down a bit it doesn't smell anymore. I will occasionally turn it and you get a smell much like the forest floor but only while turning.

I'm on the boat about once a week to go sailing. It is a very different thing from when I was living aboard. I thinnk what I've learned is that turning the contents over is what aerates and is only required during the early stages. Over a two week period the excrement in the bucket longest will be fairly well on its way to broken down so its only the latest usages that might smell. When you turn it you wind up covering that as long as you have enough dessicant and compost and so it doesn't smell and seems to continues breaking down unaided. I might run the fan the first week after an extended use but don't seem to need to after that.

[Simes]

Hi We live onboard in the UK. We use the Natures Head system. We have found that the fan in our system needs to be kept running all of the time.
We also add an enzyme (Garotta, by J Arthur Bower) to the system each time we place compost (can't seem to fund Coir here in the UK) in the system.

The fan draws nothing worth talking about and is all but silent in operation. The system does not smell bad, it usually smells like damp soil, the fan pushes the smell of damp soil out side of the boat. If we turn the fan off the system does still work, just not as well, the doings take longer to break down.

With two of us using the system we empty once every 2 to 3 weeks. Things are pretty well broken down by then (all bar the most recent doings).
We are very happy with the Natures Head, if I were redesigning the bowl area I would have a bigger (higher) raised ridge between the urine holes and the (ermm') poop chute. This would cut down on the amount of urine entering the solids area when power peeing (does some times happen).
I would also improve the quality of the neoprene seal around the top of the solids area (ours has come unstuck, a job for the next time fully clean the system).

Other than this the system is fantastic, and I would recommend it to any one looking to improve their heads area.

Simes

[Greggegner]

I have a Nature's Head and like it. We are mostly dock bound but no orders from the head. I used the existing tank vent to connect exhaust hose to the outside. Slightly more back pressure but the fan lasted all year.

[MarcW]

Natures Head mixing issue.

We added a bead of sika, 2 beads in hieght on the ridge behind the number one holes this solves the mixing issue.

Replaced the seals with new rubber which seems to be lasting.

Great piece of kit.