How to scratch-build in plastic for model railways

30 July 2019
LEAD-46471.jpg Scratch-build in plastic
Here we demonstrate beginners’ techniques for working with plastic sheet, building a model of Highley cattle dock from the Severn Valley railway.

Ask what the most important modelling material created has been over the last 70 years and one of the most common answers will be two words – plastic sheet.

Launched by Slater's in the 1950s, (under its name of Plastikard) it's a wonderful material and there’s very little you can't make from it. Buildings, road vehicles, wagons, coaches and even locomotives - all have been made by modellers from unassuming plastic sheet.

Simple to cut and easy to glue, plastic sheet is so versatile and ubiquitous, that like Hoover, the name ‘Plastikard’ has become synonymous with all plastic sheet. We take the view that if something looks right, it is right. That's the way we approached building this cattle dock. Looking at the prototype, we broke out the tape measure, but didn't worry too much about using the dimensions. We knew that the platform top had to be lower than the bottom of a cattle wagon door and that the slopes at the end would be around 30 degrees. This information was enough to work out the platform face. After that, the model was made to fit the site. So long as we can fit cows in the pens, it can't be far out.

Most country stations should feature a cattle dock, and these will all have been built to suit the amount of traffic expected and space available on site. Ours fits in an 8in square space, so it can be added to most layouts. If you model a market town, allow for a bigger facility. Construction would be the same, but you'll need more posts and wire to complete.

Shopping list

Slater's Plastikard

2mm plain sheet

0.5mm plain sheet

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Flemish bond embossed brick sheet

Wills Finescast - Stretcher bond embossed brick sheet

South Eastern Finecast - Embossed brick sheet

Ratio - 419 – Concrete fence posts, gates and signs

K&S Metals - Brass rod (8161) 1.19mm diameter


Our chosen prototype is the cattle dock found at Highley on the Severn Valley Railway. It's not original, but a reconstruction based on the former dock at this station. It's a small facility, more appropriate to a country station that isn't in a market town.
Scratch-build plastic


The crucial part of the job is the platform face. Everything else can be ‘bodged’ if this is correct. Using 2mm thick sheet, cut the front and mounted it to the top surface. A couple of triangular fillets made from off-cuts support the joint while it dries.
Scratch-build plastic


Cutting Slater’s Plastikard is easier with the right tool. For thick sheet, a heavy craft knife works, but an Olfa plastic cutter, which carves a channel out of the surface, makes a neater job. Whatever tool you use, only cut half-way, then snap the sheet along the line to avoid ridges.
Scratch-build plastic


A liquid solvent is a neat and quick way to make joints. Just run the solvent along each joint, and capillary action will take it where it's required. The solvent works by softening the plastic and melting it together. Once it evaporates, you are left with a single piece.
Scratch-build plastic


The trickiest part of the construction are the steps at the end. Build layers of plastic for each step, then overlapped them to fit the angle. We made each step too long and shuffled them until they looked right. A wash of solvent bonds everything together and you can't see what's underneath.
Scratch-build plastic


When building a platform, there are some essential dimensions. In this case, the platform surface should be just below the bottom of the wagon door so this can be dropped down to form a ramp. The exact height will depend on your wagons, track and track underlay used on the layout.
Scratch-build plastic


Happy that the dimensions were correct, we added the stone edges from 0.5mm thick sheet, scribed with the Olfa cutter. The brick front face is standard Slater’s embossed sheet. On the top we've used South Eastern Finescale sheet – the bricks are bigger and more prominent than those from Slaters, so sand the faces flatter to represent paving bricks.
Scratch-build plastic


You can make your own fencing posts, but it's fiddly. Ratio sells a kit that costs as much as buying square plastic strip. Using matchsticks would be an option, but drilling them for the rails would be difficult because the wood tends to split.
Scratch-build plastic


The width of the pairs of gates is the only set dimension here, so we assume they are in the middle of each pen and mark the position of the posts around this. Yes, working from a scale plan would be more accurate, but this method will look fine.
Scratch-build plastic


All the posts are test-fitted into holes in the platform, but not glued in place until after painting. This is the point to ask, “Does this look right?” If the answer is no, try to work out how to fix problems. Fortunately, I was happy, so out came the paint brushes.
Scratch-build plastic


Painting starts with a coat of Humbrol 121 for the mortar. Left overnight, it's dry-brushed with a mix of enamels – Greys 27 and 66 with a little bit of Brick Red number 70 on where the animals tread. For the stone edge, mix a little white into the mortar colour and dry-brushed that on, finishing with some 147 Pale Grey for the white-painted edge. All this was carried out quickly so the colours didn't have the chance to fully dry; that way they blend naturally on the model.
Scratch-build plastic


Ratio only mould holes in the front and back face of each posts, so for the corners, I have to drill more holes. Push a sharp object into the plastic to match the centre of each hole and use this to guide the drill bit. There's not a lot of leeway either side of the hole, so if the bit wanders, the hole breaks out of the plastic.
Scratch-build plastic


The posts are superglued in and then wire fed through the holes to represent the rails. To keep everything in line, use lengths running all the way along the dock. The wire is fixed, then cut with a fine saw to open up the gaps for the gates. Most of the rails can then be cut to length before fitting, without worrying too much about wonky posts.
Scratch-build plastic


Rails are finally fitted - a job that consumes nearly three feet of brass rod - and the gates are glued into place. The sharp-eyed will notice that the gates can be inserted upside down because they aren't symmetrical.
Scratch-build plastic


The brass parts need a coat of primer. Masking up before spraying takes longer than the application of paint.
Scratch-build plastic


The dock is set into a landscape made from polystyrene. Being nice and square, cutting the sheet to fit neatly around it is easy. Once the glue holding it down is dry, I'll carve the polystyrene to produce the correct contours with a knife.
Scratch-build plastic


A skim of DIY store wall filler mixed with brown emulsion smooths the polystyrene and fills gaps around the walls. The road surface is carefully sanded to a nice smooth finish and painted grey using enamels. Dusting it with grey weathering powders applied with a sponge gives the final colour and texture.
Scratch-build plastic

Looking at building in brass? Find out how you can transform an etched brass kit into an impressive, unique building in our guide.

Want some houses to go with your shed? Our guide on how to build and detail a card kit is worth a read. Or if you’re interested in building some roads and pavements, our handy guide is filled with tips and advice to help you model your scene.

Need more advice? Take a look at the BRM Techniques page for all our latest guides and advice articles.