Unequal box section in brass

[michael howarth 1Participant @michaelhowarth1]

[michael howarth 1Participant @michaelhowarth1]

Is it possible to get brass unequal box section approx. 120mm x 15mm x 16g? I have had a metaphorical look around on google but nothing of this size shows up. It is intended as side tanks on a small scale loco.

Mick

[JasonBModerator @jasonb]

Is that a typo ? should it be 12mm x 15mm

Either way I think its a make yourself, if 120x 15 bend up two angles and solder together to make a box, if 12×15 cut down square tube into two L shapes and resolder

[John HaineParticipant @johnhaine32865]

Would that be rectangular?

[michael howarth 1Participant @michaelhowarth1]

Yes, rectangular section 120 x 15mm. I had thought about bending stuff up as you mention Jason but I am not too keen on soft solder on a live steam loco although a higher MP solder might do the job. I have ruled out silver soldering because of the inevitable distortion. Any more thoughts would be welcome.

Mick

[Michael GilliganParticipant @michaelgilligan61133]

Mick,

I think you are most unlikely to find Brass box-section in those dimensions.

If Copper would suit … you might like to try electroforming [i.e. thick copper plating] onto a suitable former.

MichaelG.

[JasonBModerator @jasonb]

I would have thought the paint will burn off long before the soft solder melts. and in that long rectangular section I don't hold out much hope of finding any.

How small a scale are you talking about, whats the length of the box?

[Anonymous]

Probably not in the section required but some brass unequal rectangles would be available as waveguides. Unlikely to be cheap though!

Andrew

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by mick H on 05/01/2016 08:28:12:

… but I am not too keen on soft solder on a live steam loco…

If the boxes are going to be side tanks full of water they are unlikely ever to get above 100 Celsius – will within the acceptable range for 60/40 solder.

Cheers,

Rod

[michael howarth 1Participant @michaelhowarth1]

Thanks for the ideas gents. I am afraid that copper forming is out of my league and to chop up waveguides would be unforgiveable.

Jason, the scale of the loco is 10mm to 1 foot (Gauge 1). Oddly the paint (good stuff) will still be there when the solder is flowing freely……that is using standard soft solder.(Bitter experience). I do have some 400 degree stuff which should do the job though. A few rivets will probably assist. The boiler temperature is not the problem…..it is when flames go where they shouldn't or accidental fuel spillage occurs that causes the problem. In a perfect world these things would not occur but not in my world!

A perfectly good alternative and perhaps more realistic size would be 50mm x 15mm …..laid on edge…..but I still cannot locate any. I am now thinking of taking a length of brass channel ….say 15mm x 5mm……then after filing in some "V" sections where the corners are to be, bending it up to form the rectangular shape carcase, perhaps silver soldering the two meeting edges. Then rivetting and soft soldering on the side sheets. I am not very good at that sort of work though, hence taking the lazy route and thinking about using box section.

Mick

[michael howarth 1Participant @michaelhowarth1]

Thank you for your contribution Rod and I accept your point and as previously mentioned I might get away with it in a perfect world. The tanks are of course adjacent to the boiler which at 60 – 70psi is around the 155 deg.C mark and perilously close to the MP of soft solder. And if the tank(s) run dry as a result of taking ones eye off the ball or poor engine management ( a speciality of mine) I fear that I might be getting close to disintegration and goodbye to a lot of hard work.

I have seen boiler designs from the era of LBSC and other bold men where the copperwork is rivetted and caulked with soft solder but this would surely require a high degree of craftsmanship……and still be totally unacceptable to a modern boiler inspector.

Mick

[JasonBModerator @jasonb]

What about some 6×12 to form the sides and possibly bottom, 1.5 (16swg) for the sides then drill and CSK for 10BA brass scews. Either tin with softsolder and then sweat together once assembled or use some JBWeld.

[John HaineParticipant @johnhaine32865]

I have a foot or so of (I think) WG16 (or maybe WG14?) left over from my PhD, I'll go and measure it, you would be welcome to a couple of bits if they would suitable. Waveguide of this size is nowadays totally redundant for its original purpose.

[duncan webster 1Participant @duncanwebster1]

Even if the tanks ran dry, they are not part of the boiler. There is no way they are going to get up to the melting point of solder. Hundreds if not thousands of model locos have soft soldered tanks, and I've never heard of anyone having problems

[Ian S CParticipant @iansc]

On one or two of my Stirling Engines, the water jacket is soldered on to the motor on the theory that if there is water in the jacket, the solder won't melt. On those motors the red hot hot cap is about a couple of inches away. Another motor has the jacket assembled with JB Weld, it's a bit hard to solder stainless steel to aluminium.

Ian S C

[JasonBModerator @jasonb]

How were you intending to fit a top and bottom to this box section tank?

[Steven GreenhoughParticipant @stevengreenhough56335]

If the boiler is internally fired then I can’t imagine a problem. If it’s externally fired then a seperate flame-shield between the tanks and the boiler should help alleviate any worries (if theres room, and providing I’m not barking up.the wrong tree…)

[michael howarth 1Participant @michaelhowarth1]

Jason….your plan is simple and neat and a lot easier than my idea of channel. As to fixing top and bottom I had originally thought of HMP soft solder/ screws/rivets . I am still putting ideas together because I am scratchbuilding the superstructure onto a rolling chassis that I have almost finished. I have no plans for the superstructure, just photographs and approximate dimensions. I am not even sure at this stage whether it is worth designing the tanks to hold water as their capacity would be limited and a simpler direct boiler refill system as used by the 16mm fraternity may be a better option. I am being persuaded of the gentlemen of the forum of the virtues of soft soldering but I have to confess to a mishap with a spirit fired tank engine when, after a brief overflow of fuel the cab unsoldered and fell apart ……..but to be fair the side tanks did not!

John Haine, I have sent you a pm.

Mick

[michael howarth 1Participant @michaelhowarth1]

I now have what I require thanks to the generosity of a forum member. Thank you for your contributions.

Mick

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