Assembling the instrument faces
Sunday, 27th December, 2015
With the return of the custom dry transfer or ‘rubdown’ sheets assembly can get under way in earnest. Many aircraft instruments of the period are imprinted in an off-white or creamy colour, and in the model this is represented by the hue of the paper or plastic sheet onto which the rubdown is transferred. However, photographs of the Mk IX cockpit show significant exceptions: Some airspeed indicators, for example, are figured in a foxy red while altimeters can have a mix of green and white. This requires a trip to an art supplier to source matching coloured papers. Where instruments demand two or more colours, at least one of them must be carefully added using a fine liner pen to colour up the substrate where it shows through from beneath the dry transfer. It is best to experiment before committing to the final job.
Typically, assembly continues with the cutting out of the little instrument discs from their substrate of paper, card or styrene. I find this is best done with sharp scissors. The cut disc serve as a templates for their clear parts.
Next the instrument needle or needles are transferred from the ‘white’ dry transfer sheet to the lowermost clear disc, and invariably a separate ‘grey-black’ rubdown is needed to represent the needle boss. It is the thickness of this clear layer that raises the needle proud of the instrument face, thereby imparting a three-dimensional effect that much enhances realism. Need I say that this can be an extremely fiddly job that must be carried out with careful reference to the instrument face itself in order to get component parts orientated correctly.
Often at this stage I carefully dust the instrument face with a hint of mid-grey or brown pastel to subdue the toning.
Now the parts can be assembled: Firstly the bezel is located into its panel, then the outer glazing dropped into the bezel, followed by the needle-bearing layer and finally the instrument face itself. Again it is vital to check that all three layers are orientated correctly, not only to each other but also to the north-south orientation of the panel. My picture shows progress at this stage, with tiny Microstrip tabs emplaced to tack things together temporarily. Beware using cyanoacrylate glue for this process, because the gasses emitted can seriously ‘frost’ the styrene glazing.
The final stage involves sealing up the entire assembly with a backing of five-minute epoxy resin.
The artificial horizon and remote compass provide notable exceptions to the above process, not only because they lack conventional analogue instrument faces, but also because their three-dimensional construction is much more obvious.
In the original this comprises of a rotating disc set behind a rectangular window. I modelled a truncated version from five parts: the bezel, an enclosing tubular brass body, part of a lathe-turned disc and a faceplate cut from litho plate. A tiny styrene block is glued to the back of the faceplate to support the compass arc. Spray-painted in shades of dark grey and adorned with the artwork, the little compass repeater passes muster.
Again my picture shows the components: a bezel, a back-plate and the pivot plate for the little aircraft ‘wings’. The latter detail together with the ‘collapsed’ horizon indicator bar, are cut from tiny lengths of Microstrip glued into position unpainted.