A Water Tank for 7¼" Gauge 'Sweet William'

Some time ago I was commissioned to make this brass saddle tank, having gone through the usual steps of receiving drawings, deciding how I would make it, costing it all out, and preparing a quotation. So far so good. The inner and outer wraps were specified as 18g, whilst endplates were 16g. I planned to form the wraps by hand around ply formers and had it all nicely planned in my head. In the event the client bypassed my sources for some 'cheaper' 16g, to be used throughout, and so different methods were called for, not least the acquisition of second-hand industrial 3' rolls !

The first step was to buy necessary bar stock for a lift-off lid, and various fittings including threaded bushes and two removable strainersThe lid was turned first …...

followed by the rest of the fittings …….

comprising threaded connectors for pipework, and twelve for 2BA fixing screws.

The first of the sheet metal parts to be made were the endplates, and in addition I used some 14g (sent in error) to make slightly smaller internal doublers, providing good location ledges for the wrap edges and a strong stepped joint.

The semicircular plates were bandsawed, endplates oversized, but doublers filed to the line. Eight fixing screw bushes were silver soldered into one endplate, and clearance holes provided in the doubler, then the two were soft-soldered together, as were those for the other end..

Following that, the inner and outer wraps were marked out and cut (sorry, those two pics are in reverse order) including longitudinal flanges on the inner one. Then I started playing with my newly acquired rolls and soon found that, despite their robust 3" rollers, the bending forces in the brass were sufficient to cause noticeable roll deflection, producing a less tight roll radius in the centre than at the ends. This resulted in a barrel shape and not art all what I wanted. The problem was overcome by wrapping newsprint in varying thcknesses along the roller length in compensation, and after a lot of trial, even more error, and over- and under-compensation, I finally had linear, circular wraps. These were mated with endplates and jigged for soldering.

Believe me, although no clamps are visible above, there were plenty in evidence before the gas flame was applied. In the event the soldering at this point went well.

Edited By JasonB on 12/03/2014 07:40:55

Cont'd

A large filler port is a feature of this tank. After marking the position, a lot of closely spaced holes were drilled, comfortably within the size of the opening. The shallow upstand was cut out, formed into a ring, and silver soldered.

to ensure a good fit the up stand ring was rubbed over wet-and-dry paper held on the tank until the inaccuracies in my shape development and forming had disappeared.

then it was simply a case of aligning the fluxed component and silver-soldering in place.

Perhaps somewhat prematurely I decided then was the time to trim the endplates as well as there filler aperture, using a ballrace-guided cutter in my router.

I was quite please with the way that worked, well, smug is the word if I'm honest, but pride was severely dented when it came to making and fitting the closing panels, which caused me endless grief, a great deal of time, and a substantial reworking session. Eventually though, the panels, which incorporate a single flanged edge, were attached using 2BA c'sunk screws through the inner and outer flanges, and screws and flanges were successfully soldered all round.

After that each screwhead was spot milled down, followed by filing and sanding, to present a smooth surface, ready for painting.

The finished result is pleasingly smooth and thanks to the heavy gauge the tank is certainly robust

At 20" long and 14" outside diameter this elaborate dinner gong weighs in at 10 Kgs !I'm very pleased it's finished, and I did learn a lot in the making. To those of you used to handling much larger locomotives 10 Kgs may not sound like much, but when one's wife/camerawoman takes as long over a simple shot as does mine, well, the weight increases exponentially with time and I think it shows on my face.

Thanks for reading this, hope you gained something from it too,

Ken.

Edited By JasonB on 12/03/2014 07:41:32

ken

That's excellent work I have sent you a private message.

regards John

An additional photograph, overlooked before, showing the two pairs of all important mounting brackets. The short i" xI" angle iron ones are for the front, with one face made concave to fit the curve of the smokebox.

All attach to the tank with 2BA screws into the integral threaded bushes shown earlier.