Is This A Good Toilet Unblocking Idea?

[RichardS]

OK - those of you of a sensitive disposition please look away now, but I've spent another hour today unblocking the starboard toilet on this boat. Two days ago it was the port Jabsco which went awol.

These are the techniques I used:

Tried swimming round to toilet outlet below water with long piece of wire. Thanfully this did not work as the consequences of success would have been too horrific to contemplate as the holding tank was already full!

Port lav - block air outlet above waterline with screwed up plastic bag, fill tank with seawater using funnel and bucket through waste access on deck, push dinghy pump into wate access and start pumping or, alternatively, reseal wate access and start pumping heads. It depends on how good the seals are on your Jabsco and how powerful your dinghy pump is and whether you can get a good seal. If you hear a loud bang you've gone too far.

This technique did not work with the stbd loo - the plastic bag simply blew out from the air release outlet every time. What worked was inserting the wooden handle of the deck broom into the waste access and giving the whole thing a good whisking. Must remember to buy a new broom!

OK, now for the science bit - can anyone see a problem with glassing in a sort of cowl over the underwater outlet with the aft end of the cowl open. Surely this will create a suction (venturi?) effect when underway which will positively suck everything out of the tanks. Surely an end to toilet problems. Or possibly not.

Has anyone ever tried/heard of anything like this?

Richard

 

[TQA]

I do not speak from first hand experience on this but from listening to the "war stories" told by the unseen heroes of Sunsail, Moorings et al, who keep the charter fleets unbunged.

Pressurising the holding tanks is almost never a good idea, there is rarely a positive outcome and when the outcome is negative the cleanup is pretty extensive. Everybody has seen a clip of a garden hose flipping about spraying everybody. Well think about that same hose connected to your holding tank!

Toilet paper type! A perennial problem was some sensitive bum with farmers would bring their own triple thickness ultra soft but clog producing loo roll with them.

If you are plumbed for pumpout it is always worth getting rid of a load and it may well clear a clog.

Run the macerator pump in reverse. N.B. against manufacturers instructions but they seemed to do it often.

In answer to your query about the venturi effect, a back of a fag packet SWAG says it's not worth doing.

 

[Deleted member 36384]

You would need relatively high water speeds for the venturi to work and how you describe it would not work either.

You need an inlet and outlet on the venturi with a flow from bow to stern. At right angles to the venturi, just down stream of the throat, you would have a port. This port would be connected to the outlet. The pressure drop at the throat would cause a pressure drop at the outlet.

The calculation is quite straight forward but you will see that you need high velocity fluid to get the desired suck. The keich would be sucked into the venturi stream and ejected out the back.

 

[DougH]

RichardS

Not the best choice of a User Name for this subject.

 

[White Horse]

Watch what gets flushed down the heads

We have a rule on board .. If its not been eaten or drunk it does not go in the heads. We don't get blockages and we managed to empty the holding tank without any problems.

We charted a Bavaria a few years back with a group of friends. We did not realise when we picked the boat up that the holding tank was near full. Would it empty. We tried everything. Apart from taking the inspection hatch off that was near the top on the side.

After numerous tacks across the Solent the tank could hold on no longer. The Skipper was the worst one on board for his use of the heads roll. Not surprised they got bunged up.

 

[activesail]

Are you too posh to bucket and chuck it?

Guaranteed no blockage problems..

 

[john_morris_uk]

To the question about are we too posh to bucket and chuck it, I am going to stick my head above the parapet and say "yes". I have tried squatting over a bucket and it's not comfortable and I go sailing for pleasure!

We have two Jabsco heads and my main problem with them is that bits of leaf from the river sometimes gets stuck under the valves and they stop flushing. If it's when you've just done the business, we usually flush with fresh water using the shower hose from the sink to squirt water down the loo.

However that is an aside from my main point which is that we never have problems with the toilets getting blocked. We have never chosen the loo paper for any reason than price and it's usually the soft stuff from the supermarket. The only thing that the family have got used to is not to use too much. Moderate amounts of even the softest loo paper are enthusiastically flushed by our standard Jabsco's and I wonder why other people seem to have so many special rules. In particular I can't get my head around no loo paper down the loo at all. What do you do with it?

I am not trying to pick a fight with those who have other practices, but lots of people read these fora for advice, and I am just trying to balance up the views...

 

[ianat182]

RichardS. Regarding the venturi effect you require; you could try gluing a small ridge like a piece of s/stl strip immediately aft of the outlet, rather like the rudder retaining clips on sailing dinghies,it will cause a resistance to water flowing past and cause a suction effect by the resistance.
A piece 1 .5" wide and 3" long with the bend in it glued at 1" from the leading edge and the 2" behind should work; glue with say Sikaflex,so it can be removed if it doesnt.Think of an upside down 'tick' inprofile.

ianat182

 

[Crabman]

The person who blocks it cleans it no problem.

 

[BlueSkyNick]

The person who blocks it cleans it no problem.

Yep, that's Rule No.2 on our boat.

Rule No.1 the old addage about what you havent swallowed etc....

Reference to condoms and tampons usually brings a giggle during the crew briefing especially if it is all men !

 

[RichardS]

RichardS. Regarding the venturi effect you require; you could try gluing a small ridge like a piece of s/stl strip immediately aft of the outlet, rather like the rudder retaining clips on sailing dinghies,it will cause a resistance to water flowing past and cause a suction effect by the resistance.
A piece 1 .5" wide and 3" long with the bend in it glued at 1" from the leading edge and the 2" behind should work; glue with say Sikaflex,so it can be removed if it doesnt.Think of an upside down 'tick' inprofile.

ianat182

Your mention of sailing dinghies has made me clarify what I'm on about! Perhaps "venturi" effect was the wrong term but in the bottom of my sailing dinghy at home is a self-bailer. When you push this open you effectively get a hole in the bottom of the dinghy with an cowl over it with an aft-facing slot. There's also a flappy plate across the hole but I think the self-bailer would still work if you removed the plate as I suspect it's mainly a safety valve in case the dinghy stops and you've left the bailer open.

Once the dinghy is up to speed the suction through the bailer is strong and you can hear it sucking away even when all the water has gone. So I'm thinking about a thing like a fixed self-bailer shape over the outlet.

The flappy plate would not be an issue on the cat because although the toilet outlet is below the waterline the water obviously cannot flood in when the boat stops.

Your advice about a temporary fitting is good. I could fit it to one hull and compare the effect.

The only thing that puzzles me is that if this works it's such an obvious modification that I can't understand why it's not a standard, or at least, an aftermarket fitting.

Either I'm missing something or I'll see you on Dragon's Den!

Richard (no S!)

 

[DogWatch]

The person who blocks it cleans it no problem.

ha ha ha ha ha ha ha ha ha

and I nearly forgot, ha ha ha ha ha ha

Tell us, what's it like living on madasacuckoo Island with all the friendly giants?

Last week I was mainly pulling out cleaning wipes, oh she was full of apologies, oh it was only the second time ever she had blocked the bog, oh how daft she felt knowing she had forgot... but with all the guilt, at no point did she head for the heads with the tool box... Oh No!

 

[VO5]

Yep, that's Rule No.2 on our boat.

Rule No.1 the old addage about what you havent swallowed etc....

Reference to condoms and tampons usually brings a giggle during the crew briefing especially if it is all men !

...nothing compared to the problems you would encounter if a child dropped a small flannel into the bowl and it was pumped into the holding tank...

...then what happens is that the flannel floats about inside the tank...and then on pumpout...the flannel floats up and blocks the outlet..the tank cannot be fully emptied...then with motion the flannel frees itself and floats about again...then the tank is filled but the pumpout does not empty it fully...very perplexing...until one day, rubber gloves and coathanger serve to fish out the stinking rag...the puzzle is solved...and thereafter all functions properly...

 

[xxyyzz]

Hmmm... maybe porta-potties aren't so bad after all....

 

[colingr]

Hmmm... maybe porta-potties aren't so bad after all....

Works for me

 

[choppy]

A school friend (Early 20's at time) tells a story of when he was invited for a late autumn weekend taking someones father's boat out. They had a disasterous weekend all round; little (Possibly none) bigger boat experience, continual F6+ girlfriends terrified etc etc & all culminated with blocked heads. They tried everything they could think to clear then not wanting to upset the old man anymore - They had dings & other problems - he disconnected the hose & tried poking flushing with no sucess. With dusk approaching pub beconing & in frustration they deceided to try centrifugal force & after a couple of goes he swung it around his head helicopter style & brings the thing down full force on the pontoon ~ ~ this worked well ! They spent a fair few hours creeping round trying to clean themselves & surrounding boats up but even after a wet night they skulked away the following morning.