Is this a good idea for a water tank?

[ronsurf]

I own a corribee, 21' long. Great boat but obviously limited room. Currently there is no water tank, so I was thinking of fitting a flexible water tank to connect to the manual water pump tap I have. But the smallest one I can find is a 50litre one measuring 0.7m x 0.7m. This is too big to fit in a locker, really. Also 50 litres is quite a bit more than I need.
So, I was thinking of using one of these: http://www.singersoutdoors.co.uk/showproduct.asp?id=1197&pgid=0&r=0/0/0/0 - a 20litre shower bag thingy. 20 litres should be enough for a weekend away, I reckon, and it should fit in a locker over one of the bilge keels.
Anybody think of a reason why not?

 

[BAtoo]

Water might taste "plasticky"; better to go for a proper water one. We had a collapsable water cube (about 40cm) which I think came from a camping shop - look there.

 

[VicS]

There is no reason for it to be made of a food grade plastic so at the very least is likely to taint the water.

I had a small double skinned triangular pillow tank made to my own measurements. It is small and for its size it was expensive but it is still in use 25+ years down the line. Only holds 5 or 6 gallons so is about the size you are thinking about.

Remember flexible tanks come in two types. Pillow tanks that are non vented and designed to go flat when empty. Shaped tanks that are vented and are designed to retain their shape when empty.

The plastic cubes (we used one for camping that I think started off with wine in it )tend to crease at the same points everytime they empty and eventually leak at those points, although that could be prevented by venting them like the shaped flexible tanks

 

[DavidTav]

I have one of the Plastimo 50l flexible tanks in my boat which is only a little bigger than yours. I can't see the problem to be honest, the tank is flexible so it just fills up until it fits the space available. I doubt if my tank fills completely, but it all works ok.

 

[freebird1]

Plastimo also make some smaller tanks down to 32 litre - they are rigid but check out the proportions as you might find what you are looking for.

 

[MacMan]

We have those for what they are designed for - shower bags - they are great but overtime will not seal properly.

OK for an outside locker but I wouldn't want to keep anywhere I expected to keep dry. They will not take any significant weight on top before the object on top would push open the opening on the front.

On the pluse side they do get remarkably warm with only a bit of sun

 

[noby]

Would a Poly Pin do the same job? A 20L one costs £12.50 here (scroll down)

 

[sarabande]

Shower bag is likely to be nowhere as near abrasion resistant as the proper item.

What about a plastic water can as used by happy caravaners ? 20 litres, with a connector.

 

[ronsurf]

Thanks for all your responses and good ideas - all better than my shower bag one!