Rolling stock in 7mm scale is normally either kit-built, scratch-built or acquired ready-to-run (RTR). The materials normally used in the construction are plastic, white metal, cast resin, brass, nickel silver, wood and card. There are many reviews and articles on the various types of kits in past Gazettes.
There are excellent plastic rolling stock kits available, from basic four wheeled wagons to complex bogie coaches, with the bulk of the parts moulded in plastic, sometimes supplemented by white metal/ brass/nickel silver castings and etched parts. Normally for glue together assembly, these are quite often recommended as the first step in 7mm modelling, particularly basic four-wheeled wagons. The plastic mouldings are generally to a very good accurate standard, and some of the manufacturers supply the kits complete with wheels and transfers; in some cases, they need additional weight adding.
Numerous examples of how to build plastic rolling stock kits are available in the Gazette archive.
These kits are similar to plastic kits except that the bulk of parts are cast in white metal (a lead-tin alloy). They have been available for many years but are becoming less popular with the advent of other media. Castings in white metal can be of excellent quality, but some , particularly those cast in old moulds, may require a fair amount of fettling (ie filing and sanding to remove mould parting lines and other blemishes) to make the best of them. The parts can be assembled by glueing or soldering. White metal is a very heavy material, so completed kits are usually quite heavy, and it can be quite soft and brittle so it needs to be handled with care.
These kits are also similar to plastic kits, but the bulk of parts are cast in resin. The resin is quite soft and light, and the parts are glued together. Excellent detail can be cast into the parts but, as with the white metal castings, some cleaning up could be necessary. The completed kits are generally quite light so weight may need to be added.
Covering all types of rolling stock, from small wagons up to large bogie coaches, these kits usually require some metalwork/metal forming and are intended to be soldered together. Some can be quite simple but others can be very complex, but they may be tackled once you have confidence in metal forming and soldering. Normally, the finished models are a reasonable weight so may not require additional weight.
Note that most kits use a mixture of the materials above as some are much more suitable than others for certain features, particularly delicate parts such as brake gear.
Rolling stock that is built from scratch may be made of any material but typically from those mentioned above; the choice is largely one of builder’s preference. Many books, articles and DVDs, etc. have been produced covering scratch-building; some are recommended below.
Although these used to be the predominant rolling stock kit materials, and they are still preferred by many scratch-builders, they have now been superseded by other materials so, currently, very few kits are available in card and wood.
These models are now the fastest developing area in the market sector for rolling stock. They are usually to an accurate standard and finish, painted in accurate liveries and run most reliably. Most goods vehicles are produced predominantly in plastic whereas coaching stock is produced predominantly in brass or in plastic.