Custom water tanks

[JimChuffff]

Hi all,

I'm doing up a barge, and I haven't left much space for water tanks... and they will need to be a funny shape to fit in. (Boat is a tjalk and tanks need to fit up in curved front). I had an idea I could make s/s ones, but the shape is going to make this very difficult. Does anyone have any experience of any of the following?

- making plastic welded tanks

- marine ply boxes lined with fibreglass/vacuum-formed plastic/anything else (eg a big plastic bag of some sort?)

- making a wooden mock-up and getting someone to build a metal one from it

 

Part of the problem is that it needs to be supported on the ribs, so needs to fit pretty snugly. I'm tending towards fibreglass as it seems to be the only option that might actually fit really well.

(I reckon I'll need 4 tanks to get about 1000l of water onboard.)

 

any ideas/wisdom/opinions would be gratefully received.

 

Jim Potter

[Guest]

Hi all,

I'm doing up a barge, and I haven't left much space for water tanks... and they will need to be a funny shape to fit in. (Boat is a tjalk and tanks need to fit up in curved front). I had an idea I could make s/s ones, but the shape is going to make this very difficult. Does anyone have any experience of any of the following?

- making plastic welded tanks

- marine ply boxes lined with fibreglass/vacuum-formed plastic/anything else (eg a big plastic bag of some sort?)

- making a wooden mock-up and getting someone to build a metal one from it

 

Part of the problem is that it needs to be supported on the ribs, so needs to fit pretty snugly. I'm tending towards fibreglass as it seems to be the only option that might actually fit really well.

(I reckon I'll need 4 tanks to get about 1000l of water onboard.)

 

any ideas/wisdom/opinions would be gratefully received.

 

Jim Potter

This isn't based on boating experience, but I am surprised that more tanks aren't fibreglass. Before his retrement, my brother in law regularly made one off fibreglass tanks for industry. He generally used MDF sheets to form one off moulds

[Ange]

Hi all,

I'm doing up a barge, and I haven't left much space for water tanks... and they will need to be a funny shape to fit in. (Boat is a tjalk and tanks need to fit up in curved front). I had an idea I could make s/s ones, but the shape is going to make this very difficult. Does anyone have any experience of any of the following?

- making plastic welded tanks

- marine ply boxes lined with fibreglass/vacuum-formed plastic/anything else (eg a big plastic bag of some sort?)

- making a wooden mock-up and getting someone to build a metal one from it

 

Part of the problem is that it needs to be supported on the ribs, so needs to fit pretty snugly. I'm tending towards fibreglass as it seems to be the only option that might actually fit really well.

(I reckon I'll need 4 tanks to get about 1000l of water onboard.)

 

any ideas/wisdom/opinions would be gratefully received.

 

Jim Potter

Hi Jim

Our s/s water tank leaked and hubby had to cut it out and replaced it with a flexible one, manufactured by Hovercraft Consultants Ltd / Duratank based on drawings he submitted. We posted loads of details on our blog - I think you can find it if you go into my profile

Happy to answer any questions

Ange

[Robbo]

Hi all,

I'm doing up a barge, and I haven't left much space for water tanks... and they will need to be a funny shape to fit in. (Boat is a tjalk and tanks need to fit up in curved front). I had an idea I could make s/s ones, but the shape is going to make this very difficult. Does anyone have any experience of any of the following?

- making plastic welded tanks

- marine ply boxes lined with fibreglass/vacuum-formed plastic/anything else (eg a big plastic bag of some sort?)

- making a wooden mock-up and getting someone to build a metal one from it

 

Part of the problem is that it needs to be supported on the ribs, so needs to fit pretty snugly. I'm tending towards fibreglass as it seems to be the only option that might actually fit really well.

(I reckon I'll need 4 tanks to get about 1000l of water onboard.)

 

any ideas/wisdom/opinions would be gratefully received.

 

Jim Potter

 

 

You can get flexible water tanks, they will need a suitable container to go in though.

 

If people can easily go in this front bit where the curve is I would use it for a seating area, the front of the curve would make it a nice feature!

 

I'm currently refitting out my barge (luxemotor style), the bilge is approx 25cm in depth, so I'm using slim 100ltr (about 20x100x55cm) tanks at around £100 each from Caktanks. The previous tanks were near the bow, removing these I have pushed the bedroom wall in by over 2ft, which is perfect for the head of the bed, and makes the room feel alot bigger.

[johnthebridge]

I had a new stainless tank water tank made for our luxemotor about five years ago. The person who did it made them for well known names in the boat world. I can't say if he's still in business. Never again. This year we started to see water appearing in the bilge, and eventually (not really believing it possible) we discovered that the tank had corroded through at several points. After removal and examination it was seen that the leaks were seeping through the stitched welding of the internal baffles.

We replaced this infernal thing with a custom made polyprop tank from Tek Tanks. They did a first class job, and were both helpful and professional. They shipped it to Ireland, within the time that they had said. I recommend them. Usual disclaimers.

[JimChuffff]

This isn't based on boating experience, but I am surprised that more tanks aren't fibreglass. Before his retrement, my brother in law regularly made one off fibreglass tanks for industry. He generally used MDF sheets to form one off moulds

If they are good enough for industry, they are good enough for me. Do you know if he used the MDF as a mould (which was removed afterwards), or did the MDF end up embedded in the GRP? From experience, MDF plus water == soggy mess, so might lead to troubles if the MDF was in any way structural.

Did he put hatches in them? I suppose standard marine water tight hatches would do the job...

 

Thinking ahead (other projects) - did he ever make GRP hot water tanks?

 

Jim

 

I had a new stainless tank water tank made for our luxemotor about five years ago. The person who did it made them for well known names in the boat world. I can't say if he's still in business. Never again. This year we started to see water appearing in the bilge, and eventually (not really believing it possible) we discovered that the tank had corroded through at several points. After removal and examination it was seen that the leaks were seeping through the stitched welding of the internal baffles.

We replaced this infernal thing with a custom made polyprop tank from Tek Tanks. They did a first class job, and were both helpful and professional. They shipped it to Ireland, within the time that they had said. I recommend them. Usual disclaimers.

Thanks for your reply - OK I'll knock S/S off my list of potential materials.

 

Jim

Edited December 12, 2009 by JimChuffff

[colin stone]

Smooth 18mm plywood box - the brown stuff used in Transit trucks is ideal - in awkward corner/space then flexible rubber tank from Duratank. I have 4 tanks totaling 6000 ltrs and been in nearly 5 years. Not a drip or drop of condensation. Plybox and duratank

Welded SS has been known to fail at the welds, brazed SS would be more reliable.

Edited December 12, 2009 by colin stone

[Guest]

If they are good enough for industry, they are good enough for me. Do you know if he used the MDF as a mould (which was removed afterwards), or did the MDF end up embedded in the GRP? From experience, MDF plus water == soggy mess, so might lead to troubles if the MDF was in any way structural.

Did he put hatches in them? I suppose standard marine water tight hatches would do the job...

 

Thinking ahead (other projects) - did he ever make GRP hot water tanks?

 

Jim

 

 

Thanks for your reply - OK I'll knock S/S off my list of potential materials.

 

Jim

MDF for moulds only.

 

I had a new stainless tank water tank made for our luxemotor about five years ago. The person who did it made them for well known names in the boat world. I can't say if he's still in business. Never again. This year we started to see water appearing in the bilge, and eventually (not really believing it possible) we discovered that the tank had corroded through at several points. After removal and examination it was seen that the leaks were seeping through the stitched welding of the internal baffles.

We replaced this infernal thing with a custom made polyprop tank from Tek Tanks. They did a first class job, and were both helpful and professional. They shipped it to Ireland, within the time that they had said. I recommend them. Usual disclaimers.

I am hearing of more and more stainless tanks that are leaking around welds due to corrosion. I am keeping a close eye on ours. One welder explained that the welds should be pickled before filling with water.

[John Orentas]

Hi all,

I'm doing up a barge, and I haven't left much space for water tanks... and they will need to be a funny shape to fit in. (Boat is a tjalk and tanks need to fit up in curved front). I had an idea I could make s/s ones, but the shape is going to make this very difficult.

Jim Potter

 

 

Keep it simple Jim.. Stainless steel fabricators are fairly common in most areas and they will be quite used to working to drawings and sketches.. Draw it as the shape of a big wedge of cheese with dimensions of all the sides, also give the fabricator an idea of the areas where it will be supported..

 

Remember too that the metal thickness must be such that it will withstand a collision with a lock-gate with up too a ton of water in it..

 

Include in your drawing detail and positions of inlet, outlet and breather connections.. With a stainless tank an inspection hatch is sort of optional..

[Guest]

Keep it simple Jim.. Stainless steel fabricators are fairly common in most areas and they will be quite used to working to drawings and sketches.. Draw it as the shape of a big wedge of cheese with dimensions of all the sides, also give the fabricator an idea of the areas where it will be supported..

 

Remember too that the metal thickness must be such that it will withstand a collision with a lock-gate with up too a ton of water in it..

 

Include in your drawing detail and positions of inlet, outlet and breather connections.. With a stainless tank an inspection hatch is sort of optional..

If what I was told is correct (welds should be pickled with acid) then a hatch would be essential. My stainless tank has no such hatch, so presumably the welds have not been treated thus. If I had known about this before building the tank into the front of the boat, I would have cut an inspection hole in the top and treated the welds myself (quite easy I am told.) Alas it is too late now.

[ChrisPy]

steel hulls make excellent water containers .............. shhh! don't tell anyone ............

[johnthebridge]

MDF for moulds only.

 

 

I am hearing of more and more stainless tanks that are leaking around welds due to corrosion. I am keeping a close eye on ours. One welder explained that the welds should be pickled before filling with water.

 

The leaks on our tank appeared to start through the onset of corrosion on the external surfaces. Quite how this happened I can't say, as the tank was located in a dry area, and was drained off every time we left the boat, even during the Summer, which I would have thought would lessen the chances of condensation somewhat. I don't know if, in welding, the action breaks down the ability of the steel to remain stainless? I'm also aware that there's stainless steel, and then there's stainless steel, so......?

We've got fuel and black tanks from the same person, in stainless, but these appear to be OK. I must say it was a bit of an eye-opener for me-after 44 years boating, always believing stainless steel to be God's gift to water tank builders. Wrong!

[Neil TNC]

I had a new stainless tank water tank made for our luxemotor about five years ago. The person who did it made them for well known names in the boat world. I can't say if he's still in business. Never again. This year we started to see water appearing in the bilge, and eventually (not really believing it possible) we discovered that the tank had corroded through at several points. After removal and examination it was seen that the leaks were seeping through the stitched welding of the internal baffles.

We replaced this infernal thing with a custom made polyprop tank from Tek Tanks. They did a first class job, and were both helpful and professional. They shipped it to Ireland, within the time that they had said. I recommend them. Usual disclaimers.

a

Gld you gave a good report of Tek Tanks, as they will be quoting for the bow and stern water tanks for Barge Maurice A (which is being built at Riversdale in Ireland)

[nb Innisfree]

The leaks on our tank appeared to start through the onset of corrosion on the external surfaces. Quite how this happened I can't say, as the tank was located in a dry area, and was drained off every time we left the boat, even during the Summer, which I would have thought would lessen the chances of condensation somewhat. I don't know if, in welding, the action breaks down the ability of the steel to remain stainless? I'm also aware that there's stainless steel, and then there's stainless steel, so......?

We've got fuel and black tanks from the same person, in stainless, but these appear to be OK. I must say it was a bit of an eye-opener for me-after 44 years boating, always believing stainless steel to be God's gift to water tank builders. Wrong!

 

 

For 'stainless' read 'stain (pause) less'

[John Orentas]

If what I was told is correct (welds should be pickled with acid) then a hatch would be essential. My stainless tank has no such hatch, so presumably the welds have not been treated thus. If I had known about this before building the tank into the front of the boat, I would have cut an inspection hole in the top and treated the welds myself (quite easy I am told.) Alas it is too late now.

 

 

I've been dealing with stainless steel fabrications for donkeys years, away from the context of boats I have never heard of "Pickling welds".. As far as I am concerned a stainless steel weld that goes rusty is simply a bad job or more probably bad welding wire, the wrong grade..

 

Herrasy* these days but in my view all the tanks on a narrowboat should be integral, mild steel..

 

*How do you spell that?