Pictures by the author James Aitken except where indicated. James is a member of the Guild Technical Committee.

AFTER MANY YEARS OF BUILDING MODELS of Southern Railway stock, I decided it was about time I built myself a layout. As I make models of planes and military vehicles in 1/48th scale as well as trains, I wanted to incorporate all aspects of my hobby. I looked around the south of England for a suitable prototype where there was a railway and a military base nearby, with a dock and perhaps an aerodrome. After quite a search I drew a blank, so decided to invent such a place.

The layout plan is largely based on Ilfracombe because it had a single platform and an engine shed and turntable, with elements of Padstow as well, hence ‘Padfracombe’ or ‘Ilfrastow’ (I haven’t finally decided on the name). I wanted to include all the relevant buildings at Ilfracombe, but due to space limitations could not quite fit exact copies of them in. For example, the goods shed, the subject of this article, in reality has 17 windows on the station side. My model goods shed on the other hand has 10, but is still 700mm long, which is plenty big enough. Similarly, the real engine shed has 13 panels whereas mine has 10. That is still big enough to hold an N and an M7.

The Risborough and District Model Railway Club, my local club, bought a laser cutter with a 500mm by 300mm bed five years ago. The idea was to encourage the members to expand our skills by teaching us 2D CAD, while saving money on the buildings we needed to build for our Okehampton O gauge club layout and our Aylesbury P4 layout. I use a free AutoCAD clone called progeCAD. There are quite a few clones of AutoCAD out there. As long as they create DXF files with millimetres as the default units, the laser cutter can cut the parts I draw.

My engine shed was the first building to be constructed for my layout, after I learned the techniques by designing the buildings for our club layout, Okehampton. The shed was designed as per the prototype with concrete blocks. This was an easy one to make on the laser cutter as the mortar lines could be scribed by the laser while the window holes and sides would be cut through the MDF.

The goods shed on the other hand was built of random rough stone which would be a nightmare to draw. I knew that the laser cutter could etch a picture onto the surface of material and thought that perhaps I could use that technique on a large building.

To etch the surface with the laser cutter, you give the software a bitmap containing a picture. The bitmap is normally in two colours, black and white. Anything black is etched by the laser and anything white is left alone. In this way the laser produces an image using a raster scan like an old TV. To get a suitable stonewall picture I needed to find an image to work from. I searched the Internet for something suitable and found nothing taken square on. Plenty of pictures exist that are taken at an angle to the wall and I didn’t fancy trying to straighten them out. The original wall image converted to black and white. The white mortar can be clearly seen. The stones are too square.

In the end I found one that showed the wide mortar courses typical of this construction, but the blocks were too square. I use a paint package called ‘paint.net’ which can be downloaded from the Internet for free. This has the ability to stretch an image, sharpen it if needed and convert a colour picture to black and white. A section of the stretched wall image.

The black and white colours have been transposed to form the correct colours for the laser cutter.

Having found a suitable image, I then stretched it in the horizontal plane until the stone looked right. Of course the picture I now have is the wrong way round, as the light areas are the mortar courses and these need to be dark so that the mortar is etched away leaving the surface of the stone behind. That is easy to do with the paint package.

The next task is to use the paint software to make an image big enough for the side of the building. The laser cutter we have will take a maximum width of material of 500mm but the shed is 700mm long. The sides are therefore split into two parts, joined in the middle where I can put a guttering down pipe. It is reasonably easy to make an image big enough to cover 350mm by the height of the side 120mm, by copying and pasting these smaller image sections over each other. With some care the joins between the copied and pasted parts can be blended in, and of course you can mirror and rotate parts of the image for variety, otherwise the side can look a bit repetitive.

The next challenge is to work out how to do the quoins at the corners of the building and around the windows. I thought about adjusting the stone bitmap to include the quoins, but decided this was far too complicated and time-consuming. The surface of the quoins seemed quite smooth compared to the stone, so I decided to cut these out separately from plain MDF while cutting the rest of the wall out of a sheet of MDF which had been etched with stonework.

As the shed sides are split halfway, I need to back this with a second layer to add strength, with a join at the two thirds mark. In the end I decided to make sides and ends of the shed from three thicknesses of 2.2mm MDF. This gives me a near scale one foot thick wall which seemed about right, and allowed the inner faces to be etched with the outline of the quoins. I also stagger the joins between the sheets. The result is a nice strong box. I used PVA glue to assemble the four sides of the shed, being careful to keep them flat by only gluing two parts at a time, weighting them down to a flat surface with tins of paint. The corners of the outer sheets were chamfered to 45 degrees using the angle sander at the club. A bit of filler was needed between the stone parts and the quoins in a few places. Half of one side with windows cut-outs and cut out on the right for the end quoins. One of the ends of the shed with quoins assembled onto a second layer of MDF The quoins for three windows and one end

To make the shed look the part, the most time consuming aspect is the painting. Before final assembly, the four sides are painted with a suitable off-white emulsion paint. I used some match pots left from decorating our house. I apply it thinly, to make sure that the paint gets right into the etched mortar courses.

Once that dried, I dry-brushed LNER wagon grey over the stones. For those not familiar with dry brushing, you dip the brush into the paint and then remove most of the paint by wiping the brush on a piece of kitchen towel until there isn’t much paint on the brush. This technique is used a lot to weather rolling stock. You do need more paint than you would if dry brushing a loco or wagon for weathering, as there is a lot of stone surfaces to cover. Too much paint on the brush and the grey goes into the mortar course. It’s a fine balance, which you’ll find when you try it out. After a while, the kitchen towel gets wet with paint, and this is a good source for getting the right amount of paint onto the brush instead of getting a fresh load from the paint pot. It took two to three hours to dry-brush each of the long sides of the shed. The end dry-brushed with grey The end complete with rusty rails and light grey paints dry brushed over the base coats

Next, I dry-brushed Precision Paints rusty rails colour over the grey but sparingly, as I just needed to get a variety of colour onto the stones. The quoins were largely just grey with a dash of rust. A bit of light grey dry-brushed over the sides added a bit of variety. I used LMS wagon grey this time. I really like the look of the shed now it is complete.

I made up a platform for the inside of the shed, drawing it using the CAD program and cutting the parts out from 2.2mm thick MDF on the laser cutter. This has a planked surface, random stone front wall, and steps at both ends. These are created using layers of 2.2mm MDF.

I wasn’t able to find a good side picture of the shed so it was hard to establish how many panes of glass there were in each window, as different pictures appeared to show different window designs! In the end I decided that three panes wide by five high felt about right, and drew that. The windows themselves are cut from two layers of 0.8mm thick white Rowmark, an acrylic plastic, with a layer of 0.5mm thick clear acrylic between them. These are glued together using Plastic Weld, making use of capillary action. I held the three layers together in my fingers and touched a paint brush loaded with solvent on the edge. The solvent runs between the layers but stays away from the glass face. The windows once set are weathered using very dilute black enamel and then glued into the window reveals.

Roof trusses of a simple design are laser-cut from 3mm MDF and fit into slots in the inner layer of the sides. The roof is 1mm MDF glued to every other roof truss so that the roof can be taken off if needed. The Ilfracombe shed roof is covered in slate, these being represented on the model by 120gsm paper, laser cut into strips and glued to the MDF with Gorilla Glue. I tried other glues, but they grabbed too quickly and did not give me time to slide the sections of tiles into alignment. Gorilla Glue takes about two to three hours to set so there is plenty of alignment time. Do take care with this glue though and wear gloves otherwise it will discolour your skin.

Guttering uses the metal stays from an old umbrella, handily picked up at a council recycling tip. Down pipes are plastic rod bent to shape over the spout of a kettle and pinned to the side using 0.8mm brass rod.

The overall model looks the part. The layout isn’t advanced enough to show the model in situ, but at the top of this article you can see it outside in the sunshine.