Fitting a "holding tank?"

Tranona said:
There is no legal requirements to fit a holding tank to existing boats nor indeed to new boats except in some waters such as the inland canals in UK. In countries where there are restrictions on sewage they are expressed in terms of limiting discharge.
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1. We don't intend to keep the boat in the UK forever, and we do tend to go abroad.
2. In countries where restrictions on discharge exist (Holland & Spain to name but a few), the presence of any kind of holding tank avoids a lot of agro.

You may consider this 'A cheap product that does not do a proper job', but I'd rather have that in place than have to waste my time arguing the finer points of local law with some foreign officials.
 
OR4751 said:
1. We don't intend to keep the boat in the UK forever, and we do tend to go abroad.
2. In countries where restrictions on discharge exist (Holland & Spain to name but a few), the presence of any kind of holding tank avoids a lot of agro.

You may consider this 'A cheap product that does not do a proper job', but I'd rather have that in place than have to waste my time arguing the finer points of local law with some foreign officials.
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You are overstating the problem. The restrictions have been around for years and folks cope with them. No evidence that anybody has issues with foreign officials over holding tanks.

If you are serious about wanting to use your loo without discharging direct then fit the proper kit. Not always easy or cheap but when you look at the proper systems in the sources I suggest then you will realize how inadequate that product is. It has its use as a token nod or if you have a very small boat with no space. Knowing your boat it justifies doing the job properly.
 
Murv said:
I don't think it's designed for pump-out is it? just manual emptying?
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You may be misunderstanding the wrap-around type. They are for permanent installation, emptied using the toilet pump. It would be a fairly major task to take it out for emptying, particularly because it has no facility to close the openings.

We had one for several years, living aboard for six months per year. Reliability was not great but probably adequate for infrequent use. Their big advantage is that a diverter valve is built in, enabling solids to be held while liquids can go straight overboard.
 
Rossynant said:
Anyone already mentioned Flexible holding tank?
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I've never had to live with one, but everything I've heard has been negative. Smells permeate through them - look how it gets through even thick hose - and slight movement as the boat moves can wear holes or cause seams to leak, with unpleasant results. This happened to the original freshwater bladder in KS - no obvious hole, just a continuous slow seepage. Not too much of a problem with fresh water, but if the bladder held sewage... :eek:

Pete
 
vyv_cox said:
You may be misunderstanding the wrap-around type. They are for permanent installation, emptied using the toilet pump. It would be a fairly major task to take it out for emptying, particularly because it has no facility to close the openings.

We had one for several years, living aboard for six months per year. Reliability was not great but probably adequate for infrequent use. Their big advantage is that a diverter valve is built in, enabling solids to be held while liquids can go straight overboard.
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Ah, OK, thank you. I had assumed it was easily removable like a cassette toilet.
So, it still has merit to hold waste until full, so only really useful on short upriver jaunts unless there is good access to shoreside facilities.
 
OR4751 said:
Could you please elaborate?
What were the issues you had?
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1. The diverter valve failed several times. It is a very cheaply made thing, just a spectacle blind sealed with an O-ring. The O-ring is easily displaced, with the result that the diverter sends liquid both ways.

2. The rotating check valve is a rubbish design that doesn't work well at best. After a few months the rubber flap valve distorts, so it doesn't seal.

3. Any maintenance is tricky, with small fiddly components and poor advice. E.g. The check valve is not even listed.

4. Pumping out with the toilet pump is hard work that wears the top seal quickly and the piston O-ring to a lesser extent.

5. The vent is too small, 3/4 inch but with fittings that reduce it to 1/2 inch. In combination with the difficulty of pumping out it can become very smelly.

An example. I cleaned the tank on the water and closed both the diverter and check valve prior to hauling out. On the following day, now ashore, I found that the tank was now half full with sewage that had accumulated in the day since cleaning it. Emptying it ashore is quite a problem.

I replaced it with a gravity tank. That has its problems but you always know that it's empty!
 
vyv_cox said:
1. The diverter valve failed several times. It is a very cheaply made thing, just a spectacle blind sealed with an O-ring. The O-ring is easily displaced, with the result that the diverter sends liquid both ways.

2. The rotating check valve is a rubbish design that doesn't work well at best. After a few months the rubber flap valve distorts, so it doesn't seal.

3. Any maintenance is tricky, with small fiddly components and poor advice. E.g. The check valve is not even listed.

4. Pumping out with the toilet pump is hard work that wears the top seal quickly and the piston O-ring to a lesser extent.

5. The vent is too small, 3/4 inch but with fittings that reduce it to 1/2 inch. In combination with the difficulty of pumping out it can become very smelly.

An example. I cleaned the tank on the water and closed both the diverter and check valve prior to hauling out. On the following day, now ashore, I found that the tank was now half full with sewage that had accumulated in the day since cleaning it. Emptying it ashore is quite a problem.

I replaced it with a gravity tank. That has its problems but you always know that it's empty!
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Thanks.
Once again: when things look too good to be true, they are. :(:(
 
prv said:
I've never had to live with one [flexible tank] but everything I've heard has been negative. Smells permeate through them - look how it gets through even thick hose - and slight movement as the boat moves can wear holes or cause seams to leak, with unpleasant results. This happened to the original freshwater bladder in KS - no obvious hole, just a continuous slow seepage. Not too much of a problem with fresh water, but if the bladder held sewage... :eek: Pete
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Yes, true. Takes care to put it somewhere where it will not be damaged. As said, under deck in toilet in bows there is often bit of space. Best place, no tragedy if some smell happens there.
It's quick way to make boat 'legal', with tank. Y-valves to install in existing system, not much else.
Compared with wrap-around discussed above - same effect (can't take out or pump at station) but more capacity. Much more if needed and space is available. No vents, less valves. No pumping out if gravity emptying.

No comment on cost and longevity as this is throw-away.
But when you consider ordering welded tank custom made for your boat, all the piping, cutting hull and deck for vent and pump-out, building mounts (and strong they should be) and can't recall what else... The season may be lost until done.
 
Bought a bucket with a close fitting lid, really intended for soaking nappies
Not used in anger yet.
May not comply with some or any countries regulations!
Use at your own risk!
 
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