Chemical toilets - how often and where do you empty them?

I researched this, results on my website. Seawater left in bottles for up to a month did not smell. I suspect the sulphur compounds enter the supply side water because the suction valves are nowhere near 100% effective.
Their is cross-leakage, as you say. The cross leakage (bacterial seed) then reduces the sulfate to sulfide. Seawater is high in sulfate.

(For readers that are not chemists, a "reduction" is a type of reaction. It does NOT mean the amount is reduced. You can Google it.)

Yes, seawater will get stinky if there is a seed to start the reaction and not enough oxygen.

Flushing with freshwater is one solution. No sulfate (unless the water contains sulfate, in which case no love). One common way is to tee the sink drain into the head suction and pull a sink full of water in before leaving the boat. The smell is not typically a problem when on the boat, since the reaction takes some time.
 
I had a Lavac for 17 years. Sometimes it got a lot of use, mostly it did not. It never failed to work, never got blocked and amazingly never smelt. I've sailed on lots of boats with Jabsco types and there is nearly always a sulphur smell, that goes after a good few pumps. But never a whiff from the Lavac, perhaps because there was no 'cross-leakage'?
 
Anybody want a Thetford Porta-Potti. Only used a few times many years ago and then only for pee!

I bought it for use in a campervan, which didn't get much camping done in it.
 
Just pointing out the obvious, and not trying to provide TMI ....

For most of us on this forum, if we are day sailing and the problem is just pee, a bottle with a distinctive label is much simpler. Just sayin'. And yes, there is an even simpler solution that didn't need saying.
 
As Refueller says the problem is down to users, one of the issues is in not pumping enough to clear the pipes and often require a large number of strokes. As for blocking with paper the crew need to understand how to use it and how much to use and most people don't seem to have any such problems. The exploding problem was no doubt caused by over pressurising and trying to force the blockage through again what one could describe as user error or lack of understanding. There is also the problem of a sulphurous smell after standing for some time that can be cured or overcome simply by flushing the toilet and pipes with fresh water and then closing the outlet valve. There is a world of information about the use and maintenance of sea toilets of all types for those prepared to look for it.
A chemical toilet with all the handling that it requires and inconvenience other than for small boats that cannot accommodate a sea toilet is enough reason for most not to venture down that path but to seek to master the sea toilet like 99.99% of others do.
One of my heads is the normal sea one. The other I took it out and put a porta Potti in. It’s my “holding tank” for use in a marina. Lasts 3 days, just.
Easy to empty the cassette in the marina toilets. Not a problem
 
Just pointing out the obvious, and not trying to provide TMI ....

For most of us on this forum, if we are day sailing and the problem is just pee, a bottle with a distinctive label is much simpler. Just sayin'. And yes, there is an even simpler solution that didn't need saying.
A bit of thread drift, working offshore Angola, Texan mate, chewed baccy, used to spit in a Coke can! He used to leave it in on the desk. Yup you’ve guessed it, a contractor picked it up and took a swig! Yuck!
 
Surely in this day and age a normal sea toilet with no holding tank is a bit of a liability? You can't use it in a marina or a nice anchorage, or on any kind of inland waterway.
The point of a porta potty is just that it's a very cheap, simple way to get a holding tank. It comes with compromises but so does the cheap, simple way to do pretty much anything...
 
Surely in this day and age a normal sea toilet with no holding tank is a bit of a liability? You can't use it in a marina or a nice anchorage, or on any kind of inland waterway.
The point of a porta potty is just that it's a very cheap, simple way to get a holding tank. It comes with compromises but so does the cheap, simple way to do pretty much anything...
No compromises for me, it just works. Normal sea toilet? I have no qualms with pumping overboard offshore, it degrades easily enough.
 
A bit of thread drift, working offshore Angola, Texan mate, chewed baccy, used to spit in a Coke can! He used to leave it in on the desk. Yup you’ve guessed it, a contractor picked it up and took a swig! Yuck!
Friend of mine ended up in Hospital from a 'swig' of a mineral water bottle left on the Office table. Stupid employee had left a bottle of Caustic Solution (unlabeled, unsealed) ....

Luckily my Pal spat out before it went down the throat ... but it did extensive damage to his mouth and glands ...

3 yrs later - he still has medication to help his glands etc.
 
I guess the compromise compared to a holding tank is just capacity.
Yes indeed. My motorhome is fitted with a Thetford C2 cassette, the bigger one, whose capacity is 20 litres. When full it is a bit of a struggle to lift out of its locker in the side of the van. The holding tank on the boat has a capacity of 55 litres.
 
Surely in this day and age a normal sea toilet with no holding tank is a bit of a liability? You can't use it in a marina or a nice anchorage, or on any kind of inland waterway.
I am sure there are people who don't worry themselves about that.
 
The mullet in Albufeira Marina are numerous and big!
I used to spend a bit of time in the Vilamoura marina when the company yacht was based there, The mullet were flourishing there too. Eventually they stopped kids fishing for them..... Mostly because some were using spear guns and weren't to concerned about hitting boats.
Comment from one guy there, live on mud, taste like it too..
Wonder what the marina ones tasted like...
 
I used to spend a bit of time in the Vilamoura marina when the company yacht was based there, The mullet were flourishing there too. Eventually they stopped kids fishing for them..... Mostly because some were using spear guns and weren't to concerned about hitting boats.
Comment from one guy there, live on mud, taste like it too..
Wonder what the marina ones tasted like...
Caca?
 
A bit of thread drift, working offshore Angola, Texan mate, chewed baccy, used to spit in a Coke can! He used to leave it in on the desk. Yup you’ve guessed it, a contractor picked it up and took a swig! Yuck!
A skull and cross bones on mine.

Many marinas around here do not allow dumping porta-potties. Too many messes. So you have to haul it home.

The desiccating/composting toilets are a major improvement. Lighter (depends on the design), much greater capacity, easier to service, less or no odor. I don't see any place for porta-potties anymore. Even in a daysailor.

21b.+head+on+dock.jpg


DIY Desicating Head

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My last boat had an installed head with tank. Well maintained, I liked fine and would prefer it for most cruising. The desicating head is for small boats and places where there is no pump-out (common in the US on lakes etc.).
 
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