Replacing leaking flexible water tank

[Denizen of the Deep]

Grr!

 

The big bloated flexible water tank liner in the boat I bought three years ago sprang leaks in a few places including, apparently, around the inlet port and filled the bow cavity with water that was luckily contained there and which I spent an energetic morning bailing and pumping out. The bag seemed to be the custom shaped type designed to fit the space in my Liverpool boat quite well. A previous owner had used 1" thick polystyrene slabs to seat it on and insulate it, I guess.

 

I called Duratank of Southampton, who may well have made this leaking tank, only to find that as from September this year they are no longer making these custom tanks as "it's no longer profitable".

 

I don't think I want to look at repair not least because I can't see how you'd remedy a leak round a port, and also because the liner may be up to 15 years old already and a replacement of some sort seems wiser.

 

* Does anyone know of companies still manufacturing custom-fit flexible drinking water tanks? *

 

I may need to look at rigid plastic tanks too, but I haven't got much of a hatch space to fit one through and it might mean cutting a slightly wider hatch in the deck.

[Mad Harold]

 

The only company I've seen advertising custom tanks is Duratank.

Perhaps an "off the peg"bladder tank would fit the space you have.There is one in my boat,and it folds enough to fit the bow space when empty,and on filling it expands to fill the available space.It's not very big though,it only holds 23 gallons.

[Denizen of the Deep]

Thanks for your reply, Furness

 

Yes, Duratank may have been the only show in town, but now they're out of it and concentrating on their hovercraft business, I think.

I've seen some 'off the peg' bladder tanks such as https://www.tanks-direct.co.uk/160-litre-flexible-water-tank-potable.html . Issues I see with these are that they don't make the best use of all the available (non-cuboid, non-triangular) space, and may need some imaginative seating to keep them from sloshing, moving around and tugging on the port fittings when the boat's in motion, smashing into lock gates etc!

[Mad Harold]

160 litres when full will weigh about 350lb 158kilos,so it won't move around too much.My tank is bedded on carpet and the sides are in contact with the hull,and even when half full or less,I can't move it. I think you need to check the dimensions of the tank when it is full and compare these measurements with your available space.It may transpire that you may ,like me have to settle for a smaller tank.

[Robbo]

1 litre of water weighs 1Kg (well at around 4°c)

Edited September 6, 2018 by Robbo

[Denizen of the Deep]

10 minutes ago, Furness said:

160 litres when full will weigh about 350lb 158kilos,so it won't move around too much.My tank is bedded on carpet and the sides are in contact with the hull,and even when half full or less,I can't move it. I think you need to check the dimensions of the tank when it is full and compare these measurements with your available space.It may transpire that you may ,like me have to settle for a smaller tank.

Yes, so it seems... Thank you.

[Robbo]

Would it be a good idea to use a over sized tank for the space?

Found these that may be of interest - https://www.tidel.biz/flexible-tanks/

[sirweste]

This is number one on my to do list for the boat. Just sent Tilley an enquiry 

[Denizen of the Deep]

25 minutes ago, Robbo said:

Would it be a good idea to use a over sized tank for the space?

Found these that may be of interest - https://www.tidel.biz/flexible-tanks/

 

28 minutes ago, Robbo said:

Would it be a good idea to use a over sized tank for the space?

Found these that may be of interest - https://www.tidel.biz/flexible-tanks/

Good work, Robbo! That does look very interesting.

[Denizen of the Deep]

18 hours ago, sirweste said:

This is number one on my to do list for the boat. Just sent Tilley an enquiry 

I just spoke to Sam at Tilley regarding the products on https://www.tidel.biz/flexible-tanks/ 

She explained they are only really able to make the 'pillow' tanks (top picture) to custom specs, and not -- disappointingly -- what she called the '3D' tanks pictured at the bottom of the page and which are the sort I had in mind that could make best use of a narrowboat well deck space.

Anyhow, think I'll measure up and draw the space I have to play with and see if there's a 'pillow' configuration that might work.

[Stilllearning]

Not sure if this idea is practical, but could you fit two smaller tanks in the space, and link them in some way?

[Denizen of the Deep]

2 minutes ago, Stilllearning said:

Not sure if this idea is practical, but could you fit two smaller tanks in the space, and link them in some way?

Thanks for joining the conversation! Yes, I'd thought about that. The thing is, the outgoing (leaking) bladder tank was actually just so simple, and I feel really reluctant to install a more complicated (e.g. linked tanks) system until I really have to! With linked tanks I guess I'd need to be introducing another two or three 'weak' points (junctions) into the whole system, and adding complexity rarely feels good. Still, considering all options, so thanks

[Denizen of the Deep]

Update: I've had a quotation for making a custom bladder from a reinforced EPDM material from Butyl Products Ltd of Billericay, using the old leaking liner as a shape template. Am now in the process of double checking suitability for potable water use before going ahead with manufacture.

[Old Son]

Great news, keep us updated

[Denizen of the Deep]

On 20/09/2018 at 16:24, Neskatxa said:

Update: I've had a quotation for making a custom bladder from a reinforced EPDM material from Butyl Products Ltd of Billericay, using the old leaking liner as a shape template. Am now in the process of double checking suitability for potable water use before going ahead with manufacture.

It seems as though the material is indeed certified by WRAS for contact with human consumption water. It's nylon-textile reinforced EPDM 1.25mm thick sheeting. I took my old, punctured tank liner to their factory and we discussed how they were going to produce a bag to similar shape, and the aluminium skin fittings they'll use to pass the inlet, breather and outlet tails. Manufacture time is about 4 weeks. It's a bit of a drag living out of bottles, but tolerable as we're on a marina berth. Probably going to have to do a bit of hole enlargement in a steel bulkhead to accommodate a slightly higher outlet pipe, but otherwise can't wait to get the new liner fitted!

[Denizen of the Deep]

My new water tank bladder took about 4 weeks to manufacture. They used the fittings salvaged off the old liner so that re-fitting to tails will be straightforward. On a fine morning, we decided to fill the liner outboard and make sure it's watertight. So far, so good.

[Denizen of the Deep]

After a false start when I inadvertently twisted the liner when tightening the outlet nozzle against the bulkhead, the water bladder is now correctly located and connected. Here it is filling up. Meanwhile the pleasure of running water is restored to nb Flag Iris after three months of living out of bottled water. You don’t know what you’ve got till it’s gone!

[Stilllearning]

Congratulations on your perseverance, especially the living with only bottled water.

[Jennifer McM]

Brilliant, and thank you for sharing this info. We've got the same make of boat, so we're especially thankful

 

[ChrisJ]

Hi Flag Iris, I have just joined Canal world as I saw your topic relating to water tanks for narrowboats. We have a Duratank which is only 3 years old but seems to have sprung a leak. We are going to have it taken out so we can see if it is repairable or whether we have to replace it.

I wondered how your Butyl Products Ltd tank worked out and also I don't understand the fittings on that tank. Our existing one has a filler pipe in the top and the out pipe is in the bottom of the tank which hangs in the bow. But your Butyl seems to have both in and out connectors on the top? How does water get from the bottom of the tank, which I assume is also suspended in the bow as your photo shows ring fittings to attach the top of the bag to the boat bow?

 

Does anyone know of a company that would be able to test and reseal a Duratank, as I am not getting much help from the now defunct company.

Any advice would be gratefully received.

[blackrose]

When I read figures of "1.25mm thick" and "3 years old and sprung a leak" I'm afraid I can't help thinking that these bladders aren't really fit for purpose. Well, perhaps some are and some aren't because some people will say theirs has lasted many years.

 

But since the main purpose of these bladders is to avoid the time & hassle of repainting an integral tank, then at what point does the time, expense and hassle of replacing a leaking bladder start to outweigh repainting the tank, and at what point does a bladder cease to be an advantageous option?  

 

I know that the steel of a rusty tank has to be de-rusted & treated before installing a bladder, plus it needs insulation to stop condensation forming between steel & bladder. I considered a bladder for my boat, but I decided by the time I'd done all that steel prep work I may as well just do a bit more prep to take it back to steel and epoxy the tank. 

Edited September 30, 2021 by blackrose

[reg]

3 hours ago, blackrose said:

....... I may as well just do a bit more prep to take it back to steel and epoxy the tank. 

Could I ask how successful this has been?

I am now to old and decrepit to crawl into my water tank so am now looking at a more permanent solution to my tank blacking.

Previously I have done it myself every 2 to 3 years but if I tried to crawl into the tank now there is a very strong likely hood that I might have to stay in it. 

 

 

[David Mack]

On 30/09/2021 at 15:14, ChrisJ said:

Hi Flag Iris, I have just joined Canal world as I saw your topic relating to water tanks for narrowboats. We have a Duratank which is only 3 years old but seems to have sprung a leak. We are going to have it taken out so we can see if it is repairable or whether we have to replace it.

I wondered how your Butyl Products Ltd tank worked out and also I don't understand the fittings on that tank. Our existing one has a filler pipe in the top and the out pipe is in the bottom of the tank which hangs in the bow. But your Butyl seems to have both in and out connectors on the top? How does water get from the bottom of the tank, which I assume is also suspended in the bow as your photo shows ring fittings to attach the top of the bag to the boat bow?

 

Does anyone know of a company that would be able to test and reseal a Duratank, as I am not getting much help from the now defunct company.

Any advice would be gratefully received.

I have tagged @Neskatxa as she may not have seen your reply to a 3 year old thread.

[ChrisJ]

Thank you very much for tagging Neskatxa. I'm afraid my technical knowledge of Canal World is not up to achieving that.

ChrisJ

[Denizen of the Deep]

43 minutes ago, David Mack said:

I have tagged @Neskatxa as she may not have seen your reply to a 3 year old thread.

Thank you David. I think I had a bit of a technical issue there...

The story with that butyl bag was that it failed after only a year or so. Found it swimming in water in the bow cavity. I suspect that one of the welds around a fitting had failed. The remedy was to remove the bag, write it off as a well intentioned failure, and ask the great guys at Candle Bridge Fabrications (now based at Braunston Marina) to clean out the integral tank and paint it with a food-grade epoxy paint. The tank is now in service again at full capacity. 

 

Modern boats seem to be built with cuboid stainless or plastic tanks, offering lower capacity but vastly improved quality, reliability and accessibility (usually slotted under the foredeck, I think), and that's what I would look for in a new boat. For integral tanks, butyl liners seem dody and tricky, and cleaning and painting (to protect the inside of the hull) seems the best choice to me.

 

Again, apologies for the inadvertent radio silence and thanks for the interest shown! :)