The now departed NSW rugby league football player and commentator Rex Mossop was well-known for his oxymorons and malapropisms. One of my favourites was his statement that a football team he was watching and commentating on was making forward progress: as if there’s any other sort of progress? Perhaps if I’d been modelling as long when I heard this gem as I have been now this statement of his would have made more sense. I feel like I’ve been making forward progress for the last few weeks but it’s taken quite a while to get to the try line.
I’ve been working on the abutments and retaining walls for the bridge I wrote about in my most recent blog posting. Once the mdf formers had been cut to size there were essentially three jobs to complete:
1. Each piece of mdf had to have specific faces covered in a thin layer (approximately 3mm) of DAS modelling clay which is held in place by first coating the surface to be covered with a thin layer of PVA glue. This process is similar to that used in the brickwork for the station building I wrote about earlier this year. Once the DAS has been allowed to dry for at least 12 hours the surface is sanded with some 200 grit glass-paper wrapped around a cork block to smooth out the surface. I don’t sand the surface till it is totally smooth but leave quite a few finger indentations and other rough edges.
2. After being sanded the surface of the DAS was scribed with a series of horizontal lines to represent the join lines of the wooden form work used in pouring these concrete sections. I made a rough estimate how far apart these should be and chose to make them about 5″ apart (about 3mm on the model). I wasn’t too worried about these being too perfectly spaced so they tended to range between 2.5mm and 3.5mm apart. I marked the spacing with pencil and then used a small engineers square and a sharp scriber to scribe the lines.
3. I coloured the clay with an india ink and rubbing alcohol mix that was a little darker than I would normally use (don’t ask me the proportions, I just put a few drops of the ink in a jar of the alcohol). I was trying to replicate the look of the concrete abutments in the prototype photo of the bridge in Murwillumbah. This concrete is in a pretty damp north coast environment so it is quite dark, stained with moss and water. After the ink/alcohol stain mix had dried for a few minutes I dry brushed on some Tamiya white acrylic paint to draw out the highlights. After this has dried overnight l’ll go back and add some judicious rust stains around the sections where metal from the girder bridge touches the “concrete”. You need to wait till the white acrylic has dried thoroughly before you use any stains or powders with red in them otherwise you will end up with pink. Don’t ask me how I know! 🙂
While this modelling process was relatively simple, it has taken me quite a while to get to the point where I could say that the job was essentially done, but I’m now happy to move onto the next project. In reading the latest issue of the Gauge O Guild Gazette, I discovered a method of making stone walls using DAS so I’ve decided to give this method a try for the foundations of the next structure I plan to build. This will be the canal/creek bed running from the backdrop to the Hunter River, which is the waterway that runs along the front edge of this layout segment. The walls and surrounds of the canal/creek will be entirely man-made from timber, stone and concrete. I plan to form a good proportion of these walls and foundations from DAS. Rather surprising when you consider that this layout is the first time I’ve ever used the stuff in a modelling project.