Repairing or replacing my water tank

[Precious Time]

My narrowboat is 40+ years old and the integral watertank in the bow has failed, and had the old pipes welded up and a bladder tank installed 4 years ago... I'm now on my second bladder tank and imminently on my 3rd, they seem to me to fail every 2 years and ideally I'd like to replace my existing set up with a permanent fix, either stainless steel or plastic  and I'm looking for recommendations or suggestions, I'd rather have the bow deck removed and a new tank slotted in.

[Ex Brummie]

How did the integral tank fail?

[BEngo]

All bladder tanks fail if they are not correctly supported so the bladder cannot fold up as it empties.  Regular emptying produces creases which fail.

  Aircraft tanks are bladder tanks, usually, but they are hung from the upper corners of the tank space.

 

I prefer a rigid plastic tank in something like ABS which can be translucent, so you can easily see the level.  Stainless steel is OK too, but dearer.  Either type needs to be well stiffened.  The tank should not go 'boing' as it fills or empties.  If it does it is likely to fail.  For stainless  go somewhere that is making a lot of tanks.  Welding stainless can be tricky and a poor weld is likely to either corrode or crack.

 

N

[blackrose]

48 minutes ago, Ex Brummie said:

How did the integral tank fail?

 

Yes, why not look into repairing the integral tank and using that going forward? It would last longer and probably be cheaper in the long run than all those feeble bladders.

[David Mack]

In new builds plastic or stainless steel tanks are usually inserted into the space below the well deck from inside the cabin before it is fitted out, the front bulkhead only extending down as far as the well deck floor.

In an existing boat built with an integral tank, the front bulkhead extends down to the baseplate, and there will be cabin lining and maybe built in furniture or a stove inside the front part of the cabin.

So to retrofit a plastic or stainless tank you either need to remove a chunk of cabin lining, fitout and part of the bulkhead, or go down through the well deck floor. The latter avoids internal disturbance but leaves you with the problem of what to do with the deck. Welding it back in would not be a good idea as you don't know what damage might be done to the tank below. Bolting in might be possible if you have welded nuts on the underside of the remaining flanges before inserting the tank. Otherwise you go for a loose lay deck, in which case you need to weld up the drain scuppers and install a bilge pump alongside the tank. This is more practical if you normally have a cratch cover in place to keep the rain out of the well deck.

Or as others have suggested, getting the integral tank repaired may be a better option.

Edited February 14, 2022 by David Mack

[Bee]

I put one of these in our boat  https://www.directwatertanks.co.uk/specialist-tanks/window-cleaning-tanks  been there for 15  trouble free years. Not great for a triangular space but ours is stuffed under the bed.

[blackrose]

It seems odd that they'd make those tanks from food grade PE and then market them as window cleaning tanks?

 

Still, I'm sure they're a lot cheaper than equivalent tanks marketed for boat use, so if the shapes work then it might be an option. Perhaps the OP could install the tanks under the bed and use the existing water tank space as a huge storage locker?

[Alan de Enfield]

Depemding on the shape of your available space you could consider a secondhand IBC.

These are supplied to Farmers containing fertiliser, chemicals etc and come in a varietyof sizes from 300 litres up to 1000 litres.

 

Around us the farmers are glad to get rid of them - Over the years I have had a several, and generally give him £10 -£15 for 'a drink' (to cover the delivery)

 

The wire cage makes a good log-box or hay rack for the horses.

 

1000 litre IBC

 

 

300 litre IBC

 

 

 

400 litre IBC

 

 

 

 

600 litre IBC

 

 

 

 

If you don't want a 'unknown usage' IBC - Cleaned and reconditioned IBCs available here :

 

1000 Litre Reconditioned Water Tanks - From £49 - Direct Water Tanks

 

Or, you can just spend £100's buying an IBC with the word 'marine' or 'boat' in the description.

[blackrose]

35 minutes ago, Alan de Enfield said:

 

The wire cage makes a good log-box or hay rack for the horses.

 

 

That reminds me, I must get a new hay rack for the horses. 🐴 😋

[BEngo]

44 minutes ago, blackrose said:

 

That reminds me, I must get a new hay rack for the horses. 🐴 😋

Is your boat stable?

 

 

[Alan de Enfield]

18 minutes ago, BEngo said:

Is your boat stable?

 

 

Neigh lad !

[system 4-50]

Those tanks are also available from Forest of the Dean (where I got my 2 x 400L tanks) where they are not specifically described as window cleaning tanks.