Lavac less smelly than Jabsco?

It would make sense, because there isn't the shared pump that uses the same space for both "clean" water and sewage.

The boats I've been on that had Lavacs, though, were generally tired well-used MABs where the bog compartment smelled anyway, so it's hard to make any judgement about just the throne itself.

Pete
 
To be fair, the Lavac has the advantage of sucking the effluent out rather than pushing it, but you need to fully flush through the hoses to avoid "nasty niffs". There is a school of thought, borne out by many experiences, that most smell emenates from the water held in the inlet pipe long enough to allow anaerobic bacterial growth rather than the effluent itself. If used frequently enough and fully pumped through there is probably little to choose between them, but most of us don't live aboard. In the long term, a permanent smell comes from the hoses themselves absorbing unpleasant matter, whether the hydrogen sulphide from the inlet pipe or the effluent itself, and the only cure is to change the hose. So to compare like with like you need to have two systems which have been used the same over an equal period - with the same quality of hose as sanitation hose is supposed to be less absorbent.

Rob.
 
Jabsco type pumps allow faecal matter to enter the inlet pipe and cause the bad smell in there. Lavas don't. Lavacs however only come in a very small bowl size and so they suit smaller chaps.
 
I have a Jabsco (3 years old), and an R&M (older). Same age & materials of pipes. The Jabsco honks and has done for 2 years. The R&M is whiff-free. I regret having the Jabsco installed.
 
My previous boat had a new Jabsco with new sanitation hoses - it always smelt when first used after only a few days. I added a fresh water tank with a diverter valve so that immediately before leaving the boat I diverted the inlet water from sea to fresh and pumped this fresh through the system. This works and no smell when next used - but all a bit of a nuisance.
My current boat has a Lavac - superb, no smell! - but I do insist all gents sit when taking a pee!
 
I wonder if the smell that people comment on, to be coming from the inlet pipe, depends on where you sail. I don't get any nasty smells, but I sail on the clean waters of the West Coast.

Colvic Watson. How does your faecal matter get into your inlet pipe? Is it because your in and out skin fittings are too close together? If it's happening in the pump / valve assembly, it needs some preventive maintenance.

If I wanted to use fresh water for a final flush, (which I don't) I could simply use the tap on the wash hand basin, which has a flexible shower attachment.
 
I have two Jabscos which stand unused for months on end and neither has the slightest smell at any time, other than a very faint lemon scent.

There have been many previous threads about how to achieve this virtually cost-free. :)

Richard
 
Dunno what you are all on about. Over fifty years of various boat ownership, all with Jabasco toilets, and nary a pong. Present HR built 1981 and still with original Jabasco and tubing with never a smell. But then there is no holding tank ... I do not know if that is a factor.

Of course, it is regularly maintained and thoroughly cleaned. Plenty of pumping to flush through a significant amount of fresh water after use. Particular care has to be taken to wash and rinse around and outside the bowl, even the most careful gentleman can get the odd drips and drops inducing collateral damage to the surrounding plumbing.

As for a sitting regulation for a simple pee, never do it myself nor would I wish to try to enforce it on guests ... how to control?
 
+1 . I replaced an old Jabsco with an electric Lavac and it was money well spent - almost completely odour free.
 
Barnac1e said:
Dunno what you are all on about. Over fifty years of various boat ownership, all with Jabasco toilets, and nary a pong. Present HR built 1981 and still with original Jabasco and tubing with never a smell. But then there is no holding tank ... I do not know if that is a factor.
Click to expand...

The holding tank is not a factor in the "pong after Jabsco after being left unused for a few weeks" problem. The holding tank and its venting can be a factor in the "pong when Jabsco is in regular use" problem. :ambivalence:

Richard
 
RichardS said:
The holding tank is not a factor in the "pong after Jabsco after being left unused for a few weeks" problem. The holding tank and its venting can be a factor in the "pong when Jabsco is in regular use" problem. :ambivalence:
Richard
Click to expand...
Understood. However, when I leave the boat for any appreciable time (anything over a week), I pump well through with fresh water, adding some disinfectant, then close off both water inlet and the larger Blakes sea-cock when the bowl is dry.
 
macd said:
"Very small" is...er, stretching it a bit, perhaps?

Lavac Popular: 349 x 425mm
Jabsco Compact 330 x 425mm
Jabsco Regular 360 x 490mm
(In practice the first figure equates to bowl diameter. The second includes the hinge area and flush water inlet.)
Click to expand...

Just draw a line round your bowler hat & cut it out. That is then the correct size of seat
 
NormanS said:
Colvic Watson. How does your faecal matter get into your inlet pipe?
Click to expand...

Because with the Jabsco (and other double-sided pumps) the same cylinder volume is used for both inlet and outlet paths. The O-ring seal on the piston is pretty good, you don't get any visible brown material in the inlet side, but I don't think anyone would sensibly claim that it's bacteria-proof.

Once a small amount of bacteria is introduced to the inlet side, it grows and spreads in the seawater there (and back up the pipe) when the system is not being used. The first few pumps of each trip remove most of it, with accompanying burst of smell, and thereafter things should be sweet until the next time they're left to multiply undisturbed again. So part of my opening up the boat routine is to lean into the heads compartment and pump the toilet a few times, then close the door (the portlight is always open) and allow the smell to dissipate. Then nobody needs to smell it during actual use.

Things like freshwater flushing also work, because there's nothing for the bacteria to feed on and grow (and the water may well be chlorinated too). Pouring things into the bowl won't do anything for this source of smell, because it's upstream of there in the inlet system. Liveaboards using the toilet continuously shouldn't have a problem because the inlet pipe is never left stagnant for bacteria to multiply. Possibly extremely clean seawater doesn't provide enough food for it to really get going.

Some people say that this sulphur-producing bacteria in the inlet side arrives purely from seawater, and is nothing to do with the sewage outlet side of the toilet. Maybe that's true in exceptionally dirty water, but I would offer a couple of pieces of evidence against it:

- Vyv's experiment in which he sealed up samples of seawater, left them in good bacteria-growing conditions, then opened them later to see if they smelled (which they didn't).

- I've replaced the toilet pump and plumbing on both boats we bought. In both cases, there was no smell until shortly after the first time the toilet was used for solids. In one boat that was two or three months, in the other two years (because of a very cramped compartment that was not much fun to use!). Smell-free until the first time a thin film of shit was spread on the inlet pump walls, bacteria growth and smell in the inlet pipe a few weeks thereafter.

Pete
 
My Jabscos have always been fragrant when in regular use and I am applying myself with diligence to the main job of skipper.

However, the first return to the boat after a few weeks away with water in the system I get that hydrogen sulphide smell from the inlet pipe

but the first few flushed and a bit of attention from the lemony spray and kitchen roll get her fresh again. However, the Lavac is fragrant all the time.

Pleasantly surprised.

It is a bloomin tiny bowl though and has a massive pump beside beside where you are sitting to make things even more bijou.

It remains the loo of last resort and is seldom used. The powerful pump seems to suck almost anything through. It is a noisy thing though.

As for those who claim their loos never smell - even when left for long periods....

I wonder if their sense of smell is as good as it once was

In a previous thread one bloke mentioned that his never smelt because he cleaned it properly and then went on to say that his daughter had given him a pack of 12 loo brushes.....

this was offered of proof of his attention to cleanliness - I wondered if it was a message from his daughter about the smell from his loo

just saying

D
 
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