Water tank

[Speedy Builder5Participant @speedybuilder5]

I need to make a water feed tank for my Speedy loco which would be housed in the driving trolley.

For choise of materials, I could use zinc sheet (Brass/copper a bit expensive in comparison)  or some sort of plastic.

If Zinc, would this affect the boiler water (water temp would be ambient in the tank).

If plastic, what sort of plastic could I use which is solvent “joinable” and what plastic would I use for the water connection bosses which is easily machinable.

Tank volume about 8 litres.

thanks in advance

Bob

[duncan webster 1Participant @duncanwebster1]

Chap at our club used a 5ltr petrol container strapped to the driving trolley behind him. Ugly, yes : easy, very.

If this doesn’t appeal you can get 110 mm plastic soil pipe with a huge range of fittings, including I think stop ends.

[Stuart Smith 5Participant @stuartsmith5]

Bob

What about this one?

https://www.onlinetankstore.co.uk/product/8-litre-water-tank/

[Speedy Builder5Participant @speedybuilder5]

Good idea Stuart, but I have limited space between the bearers of the trolley, Duncan’s idea could bear promise. I need to do some calculations.

[Robert Atkinson 2Participant @robertatkinson2]

High Density Polyethylene,  HDPE, is a suitable material for making a tank.  It as available in sheet form and can be thermoformed with a hot air gun and welded with plastic filler rod. One source, but normally in thick material, is kitchen cutting boards. Another option would be to reshape a 20 odd litre existing container. This could have filler and outlet bosses pre-moulded. Lots of AdBlue containers around.

Robert.

[Nigel Graham 2Participant @nigelgraham2]

Zinc – or galvanised steel rather than sheet zinc – would not affect the water. If it does, something is drastically wrong!

 

Water-tanks, garden equipment, cattle-troughs… of all kinds have been manufactured from steel and hot-dip galvanised for years with no deleterious effects.

If you want to fabricate the tank from plastic sheet, PVC is amenable to hot-forming and solvent-welding, so you can readily fit commercial PVC pipe and fittings to it using the solvent-adhesive sold for those. Be careful though: some plumbing parts use another plastic (polythene?) and their adhesive won’t work with PVC.

it’s best not to use whatever might look right in the kitchen departments of supermarkets: the plastic might not be what you think it is (unless the label specifies it). Design the tank to materials you can select and use appropriately. Some of our suppliers stock sheet plastics, so might have suitable ones.

While adapting a manufactured container only really works if you can find one of suitable size and shape.

If you want to use a cylindrical tank, consider a length of the toffee-brown PVC drain-pipe sold for underground duty – so made in a range of fairly large diameters. The ends could be the fittings manufactured for that purpose.

 

A further alternative is a fibre-glass one, laid up around a suitable former that could be of wood. It’s not something I’ve done so you’d need some research…. including how to avoid it sticking to the mould! Looking at fibre-glass mouldings they seem to have quite generous draught-angles to facilitate removal from the mould.

…

As an example I built a fairly elaborate splash-back / motor-shield for my Myford lathe, from 3mm PVC sheet; heating with an electrical hot-air gun for bending, making “angle-plastic” for reinforcing the joints, and assembling it with plumbing solvent adhesive. A simple, shallow cylindrical embossing in one panel gives more air-space to the end of the motor, and was produced by using the bench-drill to press the heated sheet between two wooden formers.

[noel shelleyParticipant @noelshelley55608]

Hey Bob, Find a plumber and buy an old copper hot water cylinder ! Cut it up and use the sheet,soft or silver solder. If your anywhere near me I will give you some stainless to make it of.  Noel

[Paul LousickParticipant @paullousick59116]

Line the inside of your driving trolley with fibreglass to make it water tight. Apply directly to the inside walls, no mold necessary.

Fibreglass matting, resin and hardener is sold at many hardware stores.

[Speedy Builder5Participant @speedybuilder5]

Thanks for all suggestions, I think I will research the plastic pipe idea, perhaps a double bubble (two pipes, one on top of the other). As others have said, even the fittings are easily available.

Bob

[Nigel Graham 2Participant @nigelgraham2]

Two pipes…

Try comparing internal cross-sectional areas of the candidate pipes.

Obviously your design is constrained by the shape of the space available, and the stock pipe diameters; but one above the other might limit their diameters to fit the space available.

So then a single tank of maximum fit diameter and stock availability, might not hold much less water than two of smaller available diameter in the same box; paid off by the simpler construction it would give.

[Speedy Builder5Participant @speedybuilder5]

A 100mm dia pipe will give me approx 3.8 litres which is more than enough. I don’t need to “overload” as it all just gets heavier to to lug around.  I was lucky to find an oil central heating boiler vaporising head which has a sintered pre filter which I have incorporated into the injector cold water feed.

Bob

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