A yellow metal ring

The inner wrapper of the saddle tank for my loco is a half cylinder of approximately 7 1/4" (184mm) diameter. This wrapper is 20swg (0.036" - approx. 0.92mm) brass and is to be attached to the vertical ends of the tank. It is possible, but not at all easy, to make the tank ends as flanged plates. The problem is cosmetic. The finished end plates must retain a true flat surface and the flanges need to be at sharp and true right angles to this surface.

A simple alternative way of achieving a water-tight attachment of the wrapper to the plain flat end plates would be a pair brass or bronze half-rings with the inside faces finished to the required diameter. The half-rings need to be a minimum of 5/16" (8mm) thick (inside face and one flat face).

It occurs to me that a model locomotive copper boiler foundation ring might serve my purpose and, as such, it would be in the catalogue of one of the castings suppliers. Does anyone know of a published design which has a boiler outside diameter in the region of 7.25".

Any other ideas?

P.S. If anyone should wish to know what an 'Alice' looks like try a Google images search using the key words 'Alice' and 'Hunslet' .

Reply to
Mike H
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I've used brass angle to join tanks. If you cut a series if saw cuts in one web you can curve it to any radius before riveting it to the tank plates

regards

Dave Burrage

Reply to
david.burrage

In message , snipped-for-privacy@tesco.net writes

It is one of the options that I have considered. Can you get a smooth curve or is it a many sided polygon?

Reply to
Mike H

In practice it seems to work OK. I rivet the angle to the end plates, file off any high spots and then fit the pre-rolled wrapper with the wrapper fitting over the endplate. Top (outer) wrapper can be riveted (then soft soldered) lower (inner) wrapper has to be held with screws before soldering.

In spite of being riveted up to the "polygon angle" the wrapper seems to hold it's original shape. The error is quite small over each straight length if the cuts are close. From memory I think I cut about every 15mm or so. I don't make the rivets high quality close fit structural joints - they are there for appearance and to hold the joint during soldering

regards

Dave Burraage

Reply to
david.burrage

In message , snipped-for-privacy@tesco.net writes

Many thanks - I'll give that one a try. In any case the cast ring solution looks like being ridiculously expensive! For the outer wrapper I think I shall use some of Mr EKP's un-slotted round head screws as dummy rivets for the outer wrapper. This should give me enough control to avoid deforming by over-tightening.

BTW, when 'caulking' with soft solder do you tin the components before assembly? For the final soldering do you suggest an iron or a flame?

Reply to
Mike H

I don't tin first. I flux and then warm the tank just short of solder melting point with a blowlamp but use an iron to actually run in the solder. Three hands would be usefull!. It's worked OK on a "Sweet Pea" and a "Sweet William" tank.

regards

Dave Burrage

Reply to
david.burrage

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