I’m often asked about the materials I use in modelling.
Nickel Silver is the mainstay of my work, in sheet and bar form. Its advantages are that it works well, solders well, and has a fairly low thermal conductivity, which means that when soldering a smaller iron can be used, and there are fewer burnt fingers, than when working with brass. It takes paint moderately well, certainly better than brass. The only real disadvantage is the limited availability (I get all mine from
Metalsmith). It is also very expensive in large sizes, so that I use other materials for large items like boiler fittings and wheels.
Brass is what I usually resort to for fittings too large for the nickel silver I have available. I also use it where the prototype uses brass, because only unpainted brass looks like brass.
Mild steel and
tinplate are materials that I would use a lot more of, if only they did not rust. As I discovered to my cost, even the tin coating on tinplate does not protect against the liquid flux I use for soldering (Carr’s products). Unplated steel can be soft soldered quite successfully with the usual attention to cleaning and fluxing, but it is essential to wash it thoroughly afterwards to remove the flux residues. I have used tinplate for curved components because it has much less spring in it than nickel silver. Nickel silver has to be curved to a much sharper radius than that of the finished product because it tends to spring back. The other use I make of steel is for wheel tyres, when I make my own wheels.
Stainless steel is much harder to work than mild steel, and it and aluminium are the only common materials that are completely unaffected by flux. The only use I make of it is for clamps to hold parts in place for soldering, and for this it is excellent.
Cast iron is used by wheel makers such as AGH. His castings are done in a particularly high grade of cast iron and are an absolute joy to turn. They also rust if there is any flux about.
Aluminium is a material with a lot of advantages and one big disadvantage – it does not solder. But it is cheap, readily available in a huge range of sizes, machines easily, and takes paint very well. I use it for machined components that can be held in place with screws or adhesive. It is convenient for large fittings at the front end of 4-4-0s and 4-6-0s because it is light and does not upset the weight distribution by transferring too much weight from the driving wheels to the bogie.
Whitemetal. You may be able to solder it. I can’t, and I don’t know why. I use it for casting, and when I can be sure that the component can be screwed or glued in place.