I've built a laser-cut building kit and I'd like to make the walls look like they are made of stone. What's the easiest way to do this? John Dixon, London
There are many methods for making model buildings look like stone, but this one is low-cost and effective.
The first step – paint the walls with a thin coat of PVA glue and leave to dry overnight.
Mix some powdered DIY wall filler up to the consistency of ricotta cheese or stiffly whipped double cream, and cover all the walls to a depth of at least 1mm. A palette knife is ideal for this, as is skill at decorating cakes.
Once the filler has dried hard, smooth it down and square up the corners. A coarse file works really well although sandpaper wrapped around a block would also do. This is a very messy job, so work over a newspaper, or keep a vacuum cleaner handy. Fill any large holes or dips with more filler and repeat the sanding as required.
Start by scribing the stones above curved doors and window tops. My old school compasses prove handy as one leg follows the curve while the other point makes the marks.
Horizontal courses are marked in pencil. Rather than try to measure with a rule on the model, I mark them on a bit of card and then use this to transfer the guides to the sides.
Using a pointed tool from a cheap screwdriver set, the horizontals were scribed by joining up the dots. Make sure the lines match at the corners.
Vertical joints are scribed by eye to give a variety of different stone sizes. If a line isn't perfectly vertical, I tweak it so there is apparently a slightly wider joint, just like the imperfections found in a real stone wall. Keep brushing the dust away and stepping back to look at the walls as you work, it's easy for stones to get larger without realising it.
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