IMPROVE YOUR ‘Co-bo’
It might not be one of BR’S most attractive diesel classes, but George Dent finds a way of adding a little finesse to the Heljan model.
Having an instinctive sympathy for the underdog, I’ve always been drawn to the ungainly looks and the generally grubby outlook of the Metrovick ‘Co-bo’. Hatton’s decision to produce a high-quality ‘OO’ gauge model of the ‘Co-bo’, in partnership with Heljan, was a welcome development. The model is impressive in terms of detail specification, even if the prototype could never be described as attractive. Indeed, with the model featuring a wealth of detail, there’s little in the way of upgrade work required. Instead, I decided to focus on adding a few extra detail touches to the finish, especially in terms of replacing the BR logos, which are rather lacklustre. A change of identity was also desired, along with the addition of the orange-red coupling code symbols to the front ends, which place this ‘Co-bo’ firmly in the later 1960s period.
GETTING INSIDE
A little patience is required to separate the bodyshell from the chassis. It’s a clip-on fit, but it’s extremely tight and the delicate underframe detail fittings are easily damaged, so a careful approach is essential. The supplied instructions recommend inserting a pair of credit cards or thin plastic shims between the body and chassis at one end, thus releasing the locating clips. However, I found it more effective to treat both ends to the shim treatment at the same
time, before gently wiggling the body free. The only safe way to hold the underframe during this process is by the battery boxes, which are screwed to the metal chassis block. Once the body has been lifted away, the cab interiors can be prised free, ready for painting and the addition of footplate crew. To avoid the hassle of masking the glazing during weathering, the clear plastic was gently pushed out and stored safely until it was re-fitted later.
SOMETHING DIFFERENT
For the weathering stage, I decided to employ oil paints from the Abteilung 502 range for the initial steps. The aim was to create a slightly faded, washed-out appearance to the green livery by creating grey and buff-coloured wash shades. The oils were also harnessed to add a base layer of ‘grime’ to the bodyshell, with the pigment concentrated in the various recesses, especially on the cab fronts. The point of this approach was to ensure that plenty of ‘dirt’ was deposited into those areas where an airbrush struggles to reach with any degree of subtlety. A few hours spent on this preparatory work would make the airbrushing stage far quicker and simpler. Was it a success? I’m certainly happy with the finished model, but the ‘fading’ stage didn’t quite produce the effects that I’d envisioned, with the washed-out appearance being too subtle and partly obscured by the brown ‘dirt’ washes. Furthermore, the use of oils offered little advantage over regular enamel or acrylicbased weathering washes. In fact, the oils took much longer to dry (a couple of days), so there was no benefit in terms of convenience. That said, the oils are more versatile than washes, allowing fully opaque or – with the addition of thinners – translucent finishes to be created. My finished ‘Co-bo’ may still be saddled with the prototype’s dreary profile, but the improved quality of the overall finish and a convincing weathering job have created a much more authentic scale replica.