THE CONSTRUCTION OF AN
ETCHED METAL KIT
The prospect of constructing an etched kit can be daunting however all that is needed is to acquire some basic skills to build a successful model. The skills needed are those used by scratch builders, with the exception that all of the cutting out of parts are done for you, although some trimming of parts and slots may become necessary during construction to ensure a good fit. From experience the following comments are made
An electric soldering iron of at least 40 watts should be used together with a tin based solder and a metal flux (we prefer Bakers Fluid) but Carr’s Green Label Flux and Solder Paint may be found useful. If you make a mistake brass and nickel silver can easily be unsoldered then clean off the metal and try again. To make a joint between two parts run some flux using an old brush or dipper stick into the joint, then tin the iron and apply solder to the joint with a soldering iron. Do not leave the iron for long at one spot or the metal may distort. If you are not used to soldering practice on some metal at first.
Before making a joint clean the metal and burnish it along the joint using files or a glass fibre brush (which can be obtained from model suppliers or model shows). Once the joint is made clean up with the use of scrappers, sharp scalpels or metal files. Other useful tools include a good pair of tweezers, a pin vice, a selection of drills from 0.5mm to 2mm, small screwdrivers, a selection of fine pointed plyers and side cutters etc.
Boiler bands and small details are best applied using solder paint which will prevent clogging up of etched detail with solder. Apply a thin coat of solder paint to the back of the component, place it in position and hold in place with a thin pointer. Run a little flux along the edge of the part and then apply a clean iron (with excess solder removed from the tip) to the top of the component until molten solder is seen coming from the edges.
Remove the parts from the fret using tin snips or a Stanley knife on a piece of soft wood to take away any burrs. Etched edges should be tidied up and filed smooth to form a square edge. Folds in the metal parts are usually made using half etched lines (these are on the inside of the bends normally).
A smooth jawed vice and a pair of blunt nosed plyers will also help you to make sharp bends. Where the kit requires you to fit layers of metal together known as laminating such as coupling rods you may find it easier to fold the parts together and carefully clamp in the jaws of a vice before running solder along the edges. Then file smooth and clean up.
Do not rush the work and clean up as you go otherwise the effect of the flux will soon tarnish the metal so that small parts cannot easily be joined to the work. Many of the white metal castings to detail the model can be glued in place using a super glue or an araldite.
It helps to polish castings with a glass fibre brush or files to clean off casting marks. Another alternative is to solder the white metal castings to the main parts using a low melt solder (Carr’s 70 degree Red Label Solder). The soldering iron should be turned down to a lower heat so as not to melt the castings (if your iron cannot be turned down you can use a domestic light dimmer switch between the iron and the plug).
When soldering white metal fittings to Brass or Nickel/silver the surface of this metal must be tinned first to allow the solder to grip. N.B Keep the solder between the iron and the casting which can then be solder in place and fillets of 70degree solder run into place without risk of melting the casting. Try to complete all the main metal joints before attaching the white metal fittings.