Water tank failure!

[icarusbop]

Hello:

My lady has an expanding water bag water tank for the domestic supply, the capacity is 120L, the unit has started leaking over the past weekend.
I suspect these bag type water tanks are not repairable.
So, I'm planning on a new water tank system, shall I replace with a similar bag style tank or a proper tank?
I was thinking of a proper tank but suspect this will need to consider a breather system, so I'masking if anyone can provide advice on which system is the best to opt for and how to set up the breather for a plastic tank?
Thanks.

 

[Tranona]

Depending on the type of tank you have, you may be able to get a replacement bladder. The attraction of flexible tanks is that they are cheap and conform to awkward spaces to get the maximum capacity.

A rigid tank will be much more expensive if you are not able to use a standard tank. although these are made in a range of sizes and shapes, the space available in most boats (or rather the shape) usually means you will lose a lot of capacity. A custom tank of that size is likely to be £500+ and will probably need some mods to the area to fit it securely. There are various suppliers of tanks of both types such as Vetus, Tek Tanks, Stansa. Suggest you look at their catalogues to see if they have anything to fit your space. The latter 2 also make custom tanks.

A breather is not a problem. Usually a fitting in the top of the tank with a 12mm pipe going above the heeled waterline and over the side through a vent fitting. actual location and run will depend on your installation. Tek Tanks in particular have lots of useful information on the design of tanks and systems.

 

[rob2]

You don't give any hint as to where the tank is situated, but all the above advice is sound. Some people have had problems with chafe on flexible tanks, but your existing installation seems to have worked well. If you opt for a solid tank, then the breather issue shouldn't be too difficult, the hose can be as long as you like and should terminate as high as you can get it, with a cover to prevent things dropping into it. I've considered taking mine up the wind generator pole so it's completely protected and at least a meter higher than anywhere else it can go.

Rob.

 

[oldsaltoz]

First thing to do is check the water outside the tank/bag is not just condensate.

Back a few years we had a couple of bag tanks and I noticed very small amounts of water leaking, or so I thought. On further inspection I drained the gag and fount the the contact between the hull and bas wet.

I removed them both and installed a cotton/wool mix carpet that ended a few inches above the full line for the bags. Never saw another drop of water.

Good luck and fair winds.

 

[NickRobinson]

Is the bag a Plastimo with a thick welded polythene inner?

Mine chafed and dumped its contents in the bilge. Without expectation I cut a piece off the seam and pound shop superglued on over the hole, filled and mistreated (unscientific stress testing) at home and then refitted. Was still fine when sold year plus later.

It may sort your prob temporarily while you decide what to do?

 

[icarusbop]

Thanks to all for the suggestions.

It's quite an old unit, not a Plastimo with removeable liner. The outside has gone quite inflexible, whcih I think has led to the failure.
It is located under the floor but is quite awkward to get to, through a hatch cut into a bulkhead approx 2ft square - I might have been able to climb in there 15 years ago, but no chance of it now!
I think I will replace it with a Plastimo unit whcih I have got mixed reports about, but the consesus seems to be if I line the area properly with carpet or something similar it should survive for a few years without any major problems.
The Plastimo also allow you to get replacement internal bladders rather than replace the whole unit.
Thanks.