Honky pump-out tank!

[imranino]

Hello!

 

I'm really at my wit's end here! I've been through all the threads on the topic - in fact when I originally fitted the pump-out tank last summer I used a lot of ideas found here. Yet my dump-through tank persists in stinking after flushing. And sadly flush-and-run is no option as the smell doesn't stay contained within the bathroom! By the end of the year we'll have spent more in incense than the whole toilet setup!

 

Here's the system:

 

• Dump through toilet
• Plastic tank with
  • pump out outlet on the toilet side
  • breather outlet on the opposite end
• Odourlelss/BioMagic/Yeast smell control

The breather outlet has a sanitation pipe running along to the toilet end and out a skin fitting near the pump-out plug (?) on the gunwale. I tried fitting an inline computer fan to the breather, but it either broke, and when it was working it seemed to do very little.

 

My options are, as I can see, the following

1. find a more sturdy and more powerful fan fitted to the breather
2. fit a second breather on the same end as the toilet
3. the breather hose goes from a 90º hosetail, then the pipe dips a bit before rising to the skin fitting- could this be making a significant difference? Maybe the gasses would escape better if the pipe were constantly rising?
4. all of the above

As I see it, if the ventilation were more effective, the BioMagic will do a much better job, and if a fan is working well, it'll even create a small vacuum so when the flush is used very little or no gasses will come into the boat.

 

Thoughts?

 

Thanks!

[Robbo]

Well a fan will be no good if you only have one breather. If the breather pipe dips and contains liquid, it's no longer a breather pipe.

 

But even if you let off a stick bomb in the tank you shouldn't smell it inside the bathroom, my guess is that it's the seals to/from the toilet to the tank.

Edited May 27, 2014 by Robbo

[b0atman]

is the water staying in the bowl on completion of flush ?

[Kendal]

I'm with b0atman. I had this issue on our old boat until I realised I needed to add some water to the bowl after flushing to maintain a constant water seal over the outlet. Pretty obvious some might say, but it wasn't to me initially

[imranino]

B0atman and Kendal - there's no issue with the seals, they hold water, the smell is only there when actually / just after flushing.

 

 

Well a fan will be no good if you only have one breather. If the breather pipe dips and contains liquid, it's no longer a breather pipe.

 

There's no liquid in the breather - the outlet is at the top of the tank. But how come the fan is useless on only one breather? Should I definitely add a second? And is a breather still doing its job if it dips a little bit?

Edited May 27, 2014 by imranino

[GUMPY]

How big is the breather should be at least 32mm preferably 38mm.

Anything smaller doesn't vent enough.

[b0atman]

The smell is obviously in airspace in tank and escapes when valve is opened even with adequate breather pipe you will still get the smell.

solution is to stop the smell by increasing your doseage rates.

[imranino]

How big is the breather should be at least 32mm preferably 38mm.

Anything smaller doesn't vent enough.

38mm

 

The smell is obviously in airspace in tank and escapes when valve is opened even with adequate breather pipe you will still get the smell.

solution is to stop the smell by increasing your doseage rates.

 

I can live with smell but this is intolerable - would a second breather make a difference in your opinion? Will it give the air somewhere else to escape from?

[Alan de Enfield]

Its a bit like the Insurance robot "Brian" - £165, £250, £186, Stolen ......

 

Walk down a pontoon on a nice summers day and

 

Pump-out

Pump-out

Cassette

Pump-Out

Cassette

Cassette

 

The ones with the working vents are fairly obvious

 

Probably the 'owners' do not realise but its like walking onto someones house that has dogs - there is often a 'doggy-smell'

[Naughty Cal]

Do you add anything to the tank? (Other than wee and poo of course!)

 

I ask because ours is worse when we do add chemicals and is much better left to its own devices!

[PaulJ]

The last stinky one of these I did was, as Robbo suggested, down to the seal between the toilet and (plastic) tank. The seal was leaking due to one of the brass machine screws having sheared.

[Jparry]

Are you sure the fans facing the right way .

[OldGoat]

Your installation is similar to mine, which is:-

 

Plastic tank under loo

OPEN breather in side of hull

Top flush in roof

Top pumpout in roof (these mean there's no smelly stuff stuck in pipes)

 

We tried:-

• a fan bubbling through the flush pipe - works for a day or so - but smells as you go along
• Active yeast - works for a day or so
• Odorlos - works well until the tank is 3/4 full When it begins to smell I insert a stick down the loo and stir it around to break up any still solid matter.

 

When pumping out:-

• I pump until no more fluid appears then,
• Half fill the tank with water and pump again.
• If possible extend the flush hose with a spray on the end and try to reach all corners of the tank
• pump out the residue.

The tank lasts a bit longer if I can do all of the above.

 

Observations:-

Am I correct in assuming that you don't have a separate breather - only the flush fitting. Trapped gas will smell...

I find that an occasional gentle sideways / fore and aft motion (we're on a river) helps to distribute the contents - which makes Odorlos more effective.

We have two loos, mine never smells but the main joint loo gets smelly, don't understand it.....

 

 

 

 

[Robbo]

There's no liquid in the breather - the outlet is at the top of the tank. But how come the fan is useless on only one breather? Should I definitely add a second? And is a breather still doing its job if it dips a little bit?

 

If it's blowing into the tank where does the air that's already in the tank go? If it's sucking air out how is the air currently in the tank been replaced.

 

More ventilation is always good, if you add a second do it at the opposite end of where the current breather is.

[OldGoat]

The last stinky one of these I did was, as Robbo suggested, down to the seal between the toilet and (plastic) tank. The seal was leaking due to one of the brass machine screws having sheared.

 

 

The -so called brass bolts- are sintered and don't last long. I got some 6mm stainless steel coach bolts from Screwfix (?), filed two flats on them and use them instead. No breakages since.

[imranino]

 

 

Observations:-

Am I correct in assuming that you don't have a separate breather - only the flush fitting. Trapped gas will smell...

I find that an occasional gentle sideways / fore and aft motion (we're on a river) helps to distribute the contents - which makes Odorlos more effective.

We have two loos, mine never smells but the main joint loo gets smelly, don't understand it.....

 

 

 

 

The tank has 2 outlets (besides the toilet bowl) one for pumping out the other is a breather.

 

If it's blowing into the tank where does the air that's already in the tank go? If it's sucking air out how is the air currently in the tank been replaced.

 

More ventilation is always good, if you add a second do it at the opposite end of where the current breather is.

 

Thanks Robbo - so I guess the best I thing I can do is to add a second breather on the opposite end to the current one. If that makes no different, I'll add a fan onto each breather - each blowing in a different direction so there's proper air circulation.

On the subject of fans, does anyone here have one? If so what have you used? I made mine up out of a 40mm computer fan (closest thing to a 38mm hose), and used a combination of reducers and silicone to make an inline fan. Is there anything sturdier around?

[PaulJ]

 

 

The -so called brass bolts- are sintered and don't last long. I got some 6mm stainless steel coach bolts from Screwfix (?), filed two flats on them and use them instead. No breakages since.

 

I put a stainless blanking plate on the tank, fitted an 18mm ply base and put a porta potti on top of that (as per the customers request)

[imranino]

 

I put a stainless blanking plate on the tank, fitted an 18mm ply base and put a porta potti on top of that (as per the customers request)

 

I think that was my boat before I got her!

[Alan de Enfield]

 

I put a stainless blanking plate on the tank, fitted an 18mm ply base and put a porta potti on top of that (as per the customers request)

 

Now thats a sensible solution.

 

A 'couple of days' old effluent smells a lot 'better' than a 2, 3 or 4 week old tank full

[David Mack]

What material have you got for the pump out and breather pipes? There have been comments on here before that the flexible waste hose can become permeable to toilet odours. It is generaly reccomended to use solvent weld pipe, with flexible hose only used for short lengths at connections. Also ensure the pipe layout is such that waste never stands in the pipe, as the smell will permeate more quickly if it does.

[J R ALSOP]

Elsan Blue, nothing to beat it, nice smell, nice colour and not to expensive, works OK in Porta Loo.