Quite a few members here have heard of Boomer, from Boomer Dioramas on YouTube and he has some excellent tips on creating concrete. In fact I have used his technique on my layout, plus adopted a few of my own techniques to create a realistic looking aged concrete, which on a layout, would have multiple uses. Here I describe how I created a small concrete loading platform from a foam core carcass to a finished model. The carcass was constructed from 3mm thick foam core... Using Golden Fibre paste and a spatula, a thin layer was applied to the carcass. This was put on reasonably smooth, although some areas were left rough-ish... A few close ups of the applied fiber paste... It is best to allow the fibre paste go off over night (or longer if in cooler weather) before giving it a light sand with some P120 wet & dry paper... The result was to keep some of the rough texture but at the same time, smooth the surface. The result was a concrete cancer like effect with depressions in the surface... I took a little ink stain (ink and isopropyl alcohol) left over from staining the sleepers/ties and this was thinned down a tad more with IPA and applied to the whole foundation. Yes, it does look very dark, but there is a reason for this... The wet ink/isopropyl alcohol surface dried off pretty quick, especially when you leave it in the window, baking it like a hot house ! Next up was some varied applications of grey and white paint. This paint was thinned down with a little isopropyl, which aided the drying process. I started with the grey seen in the photo below, then gradually lightened it up with various applications of white. Adding white after the grey had dried. The technique I used is to pick up a little white paint and apply it like you are dry brushing, only cresting the very top layer. The idea here is to gradually build up the colour palette, slowly and sparingly. A close up of the gradual effect created... That pretty much completes the foundation of the concrete. Next I look at adding the expansion gaps and weathering the surface further.
Next up is to cut a few expansion gaps into the top surface using the back edge of the scalpel blade. A few light strokes through the surface is all you need. Do not try and attempt this in one cut, it won't work !! You can use the corner edge of a razor saw to do this too. After cutting the expansion gaps, mix up a little black and brown paint together and thin it right down to create a wash. Take a flat paintbrush and soak up a little wash and lightly touch the expansion gap. The capillary action will draw the colour down into the gaps. Using the same black/brown wash, use the same technique to create some run off over the edges... Add a little more black to the wash to create larger stains on the top surface. Once again, take a little wash on the brush and allow it to flow off the bristles into the low crevices created in the prepared surface. Soil stains/rust stains etc can be created using weathering powders or chalks. I have a set of Mont Marte pastel chalks with several shades of browns. Choose at least two shades, a light brown/sand colour and a mid brown. Apply the darker brown (or if rust, a black/red mix) to the areas alongside the expansion gaps. Use the chalks/weathering powders sparingly and gradually build the colour up. Don't attempt one big dump of colour as it will not give you a good result. After applying the darker colours, use the lighter sand to feather out the dark colours. If you choose rust, use a light application of light rust, which has more of an orange tone. Once you are happy with the weathering, give the whole lot a light application of flat clear, either from a rattle can or the air brush. Lastly, if you wish to add weeds, take a tooth pick and apply a small bead of PVA (carpenters glue) to the expansion gaps and apply 2mm static grass. Here I chose to use 2mm brown grass and added afterwards a little 3mm burnt grass. Allow this to cure over night before giving it a light vacuum to remove any excess grass. The results are pretty good and here are a couple of close ups showing what detail you can add to something this is often left as a grey concrete platform. A little bit of time can transform a basic model into something that really catches the eye. This technique can be used for all concrete surfaces, even roads. I guarantee anyone can do this ! Oh, before I go, this is how this platform ended up on the layout... Go on, give it a try... Cheers, Gary.
