[70521]
Well-Known Member
I'm interested in this as I'm planning to go to the Baltic in a few years and hear that you need a holding tank. Really don't want to go to all that trouble in a 40 year old boat.
Compost toilets
- Thread starter coopec
- Start date
Gary Fox
N/A
Done a couple of deliveries and cruised a bit in Denmark, Germany and Sweden, and never been asked. Double check, but I have a suspicion that holding tanks are only mandatory for local yachts and not visitors. Horrible things, imagine if you had to put one in a Folk-boat!
coopec
N/A
There's a few threads on the subject:
Holding Tank in Baltic?
I think this may interest you?
The Baltic:
As with international conventions such as MARPOL, the Helsinki Convention (HELCOM Convention on the protection of the marine environment of the Baltic Sea Area) must be implemented ...i....
How is your yacht affected by MARPOL rules for Ships?
There's a few references to holding tanks/Baltic Sea here
yacht holding tank baltic sea - Google Search
[70521]
Well-Known Member
Thanks COOPEC.
dankilb
Well-Known Member
Almost everything I read when we were researching options suggested that the crank-handle type 'desiccating' toilets do work. Of first-hand accounts I'd put the proportion at around 9/10 (and that's of the ones who feel moved to post online - and if my £1000 cranky-bucket didn't work I'd sure as hell post about it). Plus the applications they're commonly used in - such as small vans - seem more (rather than less) demanding than a comparatively capacious and well-ventilated yacht.
I'm more interested in the more 'PBO-style' questions, namely: a) how can they be made to work better (if indeed there are issues with the stock setup) and b) how can you build one 'DIY'?
On 'how can they be made to work better?' - given that they run off a PC fan to ventilate the tank, and they ship with a relatively basic model, a simple mod might just be to install a higher capacity fan or double them up.
On 'how can you build one DIY?' - I'd be very keen to reverse-engineer our AirHead (and then sell it on - seeing as it's unused ? and apparently they're in high demand here in the UK among van-lifers/staycationers), but I doubt I'd have the skills. Building a GRP enclosure would be one thing. But I reckon I'd need someone to fabricate/weld the crank so that it fitted securely and worked properly (with my skill level, at least).
It's a frustratingly simple design, but when you factor in all of the molded parts (some of which obviously need 'ergonomic' consideration to re-direct the wet stuff, etc.) plus the crank, I'm not sure how easy it really would be to make your own that worked as well (or ideally better)?
I'm more interested in the more 'PBO-style' questions, namely: a) how can they be made to work better (if indeed there are issues with the stock setup) and b) how can you build one 'DIY'?
On 'how can they be made to work better?' - given that they run off a PC fan to ventilate the tank, and they ship with a relatively basic model, a simple mod might just be to install a higher capacity fan or double them up.
On 'how can you build one DIY?' - I'd be very keen to reverse-engineer our AirHead (and then sell it on - seeing as it's unused ? and apparently they're in high demand here in the UK among van-lifers/staycationers), but I doubt I'd have the skills. Building a GRP enclosure would be one thing. But I reckon I'd need someone to fabricate/weld the crank so that it fitted securely and worked properly (with my skill level, at least).
It's a frustratingly simple design, but when you factor in all of the molded parts (some of which obviously need 'ergonomic' consideration to re-direct the wet stuff, etc.) plus the crank, I'm not sure how easy it really would be to make your own that worked as well (or ideally better)?
...unfortunately in the UK they're certainly still £1000 thereabouts (£999 for Air Head, £975 for Natures Head) ?
coopec
N/A
You'd have to make up a mold and maybe you could use your Airhead to make up a mold. (It would be necessary to change the shape a bit to avoid a copyright action)
I've made up stacks of fiberglass moldings but a couple that took some care were door architrave and a molding for the shower/toilet. The photos are out of sequence: sorry! (The photo of the door architrave is a bit out of focus but I couldn't get the camera back further)
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AntarcticPilot
Well-Known Member
Maybe I'm being thick, but where can you dispose of the waste from a composting toilet? No marina I know has suitable facilities. It can't go in the compostable waste bin of authorities that separate waste - there's a specific ban on human waste, at least in our area. General waste bins strike me as being pretty antisocial. That leaves over the side in offshore waters.
A marine toilet (without holding tank) costs a few hundred and does just the same, so where's the advantage for a salt water yacht?
A marine toilet (without holding tank) costs a few hundred and does just the same, so where's the advantage for a salt water yacht?
stevie69p
Well-Known Member
What happens to the poo from babies and toddlers that are using disposable nappies? I'll bet you a fiver that the parents aren't scraping the poo off and flushing it down the loo; it's going in the bin with all the rest of the household rubbish, so I doubt a bag of dried poo and sawdust is going to make much difference once it's in landfill...
prv
Well-Known Member
It's essentially a dry holding-tank. Needs less volume for an equivalent number of uses, but on the downside it's not fully sealed (my prejudice against them stems partly from an account of one breaking loose in heavy weather and distributing its contents all over the cabin) and the emptying process is unpleasantly hands-on compared to simply opening a valve to dump a gravity tank.
Pete
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stevie69p
Well-Known Member
I'd tend to agree with that, and personally would only have one for areas where using a sea toilet would be downright anti social. Basically, everywhere I sail currently is tidal but just seems wrong to pump out as not offshore, so a dry toilet would be handy to be used in addition to a sea toilet. If lined with a compostable liner, the emptying process would be straightforward. Having previously owned a motorhome with a cassette toilet, at times that was an unpleasant experience to empty!
pvb
Well-Known Member
The prime reason that composting toilets have been popular in RVs and off-grid dwellings is that they don't use water - a precious commodity in those applications. With a boat, there's no shortage of water for flushing!
prv
Well-Known Member
I don't think you could do that, at least on a current design, because of the shit-stirring crank contraption.
You could of course have a box with a seat on top that takes sealable bags which you later throw in a bin, but it barely qualifies as a toilet system by that point
Pete
prv
Well-Known Member
And why a "composting" toilet is a perfectly sensible choice for these applications. You could even add a hatch (or arrange the building) so that you don't have to carry a bucket of poo through your living room, bedroom, and kitchen like you would on a yacht. But if you did have to, at least the rooms wouldn't be swinging around to try to make you spill it.
Pete
stevie69p
Well-Known Member
I don't think you could do that, at least on a current design, because of the shit-stirring crank contraption.
You could of course have a box with a seat on top that takes sealable bags which you later throw in a bin, but it barely qualifies as a toilet system by that point
Pete
From the research (albeit limited) that I've done on the subject, the shit-stirring part isn't entirely required, it's just helpful in evening out the drying process, so essentially people are using a basic bucket with sawdust / coir / medium of choice. Some just empty from the bucket, some use a liner. From a personal point of view, as just one person on a boat that will likely be sailing in sea lochs / anchoring in bays / occasionally venturing offshore, but whose boat doesn't really have much space to fit a holding tank, plus the no plumbing benefits.... I can see the plus points of a dry toilet, but can also see it's not the solution for everyone.
Hallberg-Rassy
Well-Known Member
Yes. Historically, one would just take it over to the Turkish side, and dump it there. Joke.
One question, where do you dump the faecal-arboreal waste from the composting? I'm all for taking responsibility for one's own ... but I can't imagine marinas would be happy with skips full of the stuff.
I mean, on a one off basis, one might get away with taking it a walk up the High Street in a bag and looking for a doggy doo bin. But how does the whole system work? And when can one start to grow tomatoes in it?
steve yates
Well-Known Member
even easier, just type ybw:searchphrase into google and it lists the forum threads at the top.
dankilb
Well-Known Member
For us it came down to this... our home marina is locked in and after close consultation with the first mate, it was decided that we didn't want the marina facilities as our sole option. We removed a 40L holding tank from the head locker and the only viable location for a large enough holding tank to be usable would be under an aft cabin bunk where the batteries and associated electrics are due to be re-located to. In their current position in a cockpit locker they're at least 4ft higher and 6ft further aft (and heavy with 4 x 110AH), so they get dibs on that space for weight alone.
We do have a second head with a regular sea toilet and I'm not sure we'd consider a composting head if it were our only option (nor is it Coopec's, of course).
As for disposing of it - I reckon it can sensibly be binned with regular landfill waste. If there were food waste recycling available, that would be even better (if you believe the converts that it is basically just inoffensive composty-type material that is produced). I doubt that enough boats would ever switch to composting to mean that it caused an issue for marina bins.
dankilb
Well-Known Member
Very nice! If I had these sorts of GRP skills I'd definitely consider molding my own unit with a removable 'bucket' fitted with a crank. It could even be electrically cranked if you were really keen!
But while I consider myself pretty good at GRP repairs, I've only ever molded crude parts and made them look decent with tons of filler, so I don't fancy my chances! The crank is admittedly quite simple, but I'm not sure how I'd hold it in place and create some sort of bearing for it to turn (I can't weld and don't have access to a lathe) - but I'd love to see someone come up with a solution.
stevie69p
Well-Known Member
I watched an interesting YT video recently where they had built a composting toilet and rather than having a crank, they used a fixed 'mixer arm' for want of a better term, and made up a gear ring that fitted to the bottom of the bucket and was driven by a cordless electric drill! So the bucket was turned rather than the mixing part.
DownWest
Well-Known Member
The simple way of GRP moulding is to lay resin and cloth onto a flat surface, Melamine chipboard for example, then trim it to size and tape it to the other bits. Having built the box with the smooth side in, add a few extra layers in the outside for strength. A bearing only needs to be a bit of tube clued to the wall of the box. Unlike a Porta Potty, the contents do not slop and gurgle....
One other solution to the holding tank for temp use while in harbour is to have a Porta Potty with a hose connection and bilge pump to a skin fitting. After clearing harbour, just pump the contents out. Would work for a few days.
