Build a plastic coach kit

Ratio’s recently relaunched plastic coach kits are the perfect basis for a modelling project. George Dent reveals how he built and improved an ex-midland Railway suburban coach kit.

Why build a coach kit, when there are so many RTR ‘OO’ gauge carriages to choose from? One good reason is that it provides a very enjoyable pastime – something we’re all searching for at the moment. Another factor is that there’s still a relatively limited array of pregrouping designs available off the shelf, so kit-building is the natural alternative.

Etched metal coach kits offer a potential route, but most demand a degree of skill and experience, along with a need for soldering tools. Plastic kits, on the other hand, are fairly cheap and suited to modellers of all skill levels. Furthermore, they can be easily upgraded or customised with only a handful of tools and equipment. Indeed, if you can make a half-decent job of an Airfix Spitfire, you can certainly build a plastic rolling stock kit!

In recent years, 3D-printed components have provided another option for carriage building but, for me, they don’t offer the same kind of pleasure as gluing bits of plastic together to form a working model. The styrene employed in plastic kits is a very user-friendly material, that can be cut, filed, drilled and shaped with very little effort and even kits that have been around for years can still offer tremendous results.

One such example features here, a Ratio LMS (ex-midland Railway) 48ft Suburban Third Class Brake coach. I’ve had a few of these kits in my stash for nearly a decade and their intended use was always as part of a colliery worker’s train for my freelance ‘Maudetown Colliery’ layout. The moulded components are good, although some of the plastic parts do need fettling to improve their appearance. Replacing a few fixtures and fittings with superior castings and fine brass wire also makes a dramatic difference, as does replacement of the supplied wheels.

TOP DOWN OR BOTTOM UP?

One issue I’ve had with building coach kits in the past is the lack of provision for internal access once the vehicle has been assembled. Plastic kits, in particular, are often designed so that the body is glued to the chassis, with the roof also permanently fixed in place. But what do you do if a passenger comes loose and how do you paint the body without ruining the glazing?

Modifying the kit to allow the body to be screwed onto the chassis is, therefore, a very

welcome improvement. As shown in the demonstration, this is a straightforward task and requires just a few scraps of thick plastic card, some self-tapping pan-head screws and a drill. That said, we do need some help in getting the bodyshell assembled squarely, without the aid of the chassis as a guide, as would normally be the case. A sheet of MDF, or other hard and flat surface, plus a pair of steel setsquares will be a great help in getting everything straight and true.

READY FOR THE ROAD

As a project carried out on the dining room table over a number of dark, winter evenings, it proved to be great fun and the bright red fictitious livery adds a vibrancy to the coach. Out of convenience, I applied the numerals with a fine calligraphy pen and white ink, so they’re not perfect, but they do suit the slightly rough and ready appearance that I was aiming for. The extra detail fittings proved worthwhile and the weathered finish will certainly suit its intended surroundings. It’s ironic, however, that while I may have finally started work on this miners’ train, my ‘Maudetown Colliery’ layout had to be dismantled before a house move last year. My hope is to build a new version of the layout in the coming years but, in the meantime, I’ll have to concentrate on building more interesting stock for it.

There are still so many pre-war carriage types that aren’t available RTR, so plastic kits offer an easy and enjoyable solution.

In most instances, it’s best to remove plastic components from the main sprue with a set of cutters. However, some sprues have the parts packed close together, making access for the cutters tricky.

Where the cutters won’t reach, use a stout, sharp blade. Work onto a sheet of wood or a cutting mat and make several passes with the blade to cut through larger attaching points. Work away from the edge of the component.

Alternatively, fix a strip of abrasive paper onto a flat surface with double-sided tape and rub the plastic parts over the surface. Use a steel rule and a set square to keep checking that the edges are straight and true.

The remains of the sprue mounting points can be flattened with a flat file. Larger components can be gripped in a vice, which makes it easier to flatten longer parts. Ensure that the dressed edge is square.

The kit is designed so that the bogie mounting pin is glued into the bolster on the chassis. To make future access easier, drill a pair of holes to allow a pair of brass pan-head screws to secure the bogies instead. Thick plastic sheet was bonded atop the floor to give the screws extra purchase. The holes in the chassis were drilled smaller than the screws, which cut their own thread into the plastic. The bogie holes were larger to allow free rotation.

The gas tanks’ straps are thin strips cut from insulation tape and brass wire formed the outlet pipes. Brake ‘V’ hangers were from an etched brass wagon detailing sheet and more brass wire created the actuating shafts. A set of brass pinpoint bearings was fixed into the axle holes, which were opened up slightly with a drill bit. The bearings were secured with cyanoacrylate. These bearings complement the replacement metal wheels.

After a few hours’ curing time, the two halves of the body were mated. Strips of wood were tacked onto the MDF with track pins to create a simple former, keeping everything true. The parts were then left to cure completely overnight, before they were removed from the jig.

Keeping the floor perfectly flat, the side frames, headstocks and bogie mounts were fixed in position. 0.9mm brass wire was shaped to form the new trusses. New gas tanks were cut from plastic rod.

The bogies were assembled around the new wheels, working on an old mirror to ensure everything was square. All four wheels should be in contact with the glass at all times and they must be able to rotate freely.

Work on the bodyshell began. The ends received layers of thick offcuts of styrene sheet, bonded at right angles, just above the bottom edges, allowing clearance for the floor. Allow the cement to cure overnight.

More delicate parts can be cleaned up with shaped needle files and sanding sticks. I cut away the diagonal truss rods and brake ‘V’ hangers from the chassis side frames, as these will be replaced with finer components.

I used an offcut of 9mm MDF as a makeshift assembly jig. Two holes were drilled into the chassis floor (which will later act as mounting points for the body), and the component was secured to the board with pan-head screws.

Using the assembly jig as a reference surface, the ends were mated with the sides, one at a time. A setsquare helped to ensure a correct 90º bond, while a magnetic clamp (www.yorkmodelrail.com) kept the parts secure.