Following the test piece I looked at in the last post, I have moved ahead and created my first full board. It actually began as another experiment on one of the "bad" pieces of foam. I wanted to test the glue I had chosen, so I took one of my 30cm square pieces of MDF and stuck the "bad " piece to it. I have used Uhu All Purpose, solvent free glue for this, available from places like Amazon and Hobbycraft amongst others for about £3 per tube.
I chose this because it's polystyrene friendly and will cure in the absence of air, which PVA and wood glues won't do. I often see people use lashings of PVA to fix large areas together, like sheets of styrofoam for terrain projects, but what they don't realise is that whilst the glue around the edges will cure, it will stay liquid in the middle. I've taken large pieces of terrain apart that have been in use for years and found the PVA still wet in the middle of large areas. It also needed to be solvent free, as solvent based glues will melt the polystyrene.
I applied the glue to the MDF and affixed the XPS (extruded polystyrene) sheet to it. In a couple of places I had been a bit generous and glue squished out the edges like an overfilled, sticky doughnut. Once I cleaned up the excess I found that the corners had lifted away, so added some extra glue there and used some small clamps to hold the sheet down. The glue set quickly and the piece was solidly stuck within about 30 minutes. I left it overnight just to be sure.
I checked the next day and there was no sign of melting or warping, and the sheet was firmly attached across its entire width. I then decided to try out the slabs effect on a larger scale (area 4 in the previous post). I gridded the sheet with 25cmm squares using a ballpoint pen. I also cut out the damaged area of the sheet, making it into a square recess. I plan to create a couple of drop-ins for this area; a trap door from balsa, a grating from some wire mesh and maybe a well or pool of some kind as well.
I then grabbed my handy rock samples and began to press them into the foam. I'd done about half the sheet when I decided to try out another technique. I must confess I have completely forgotten where I first heard of this, but I do remember one of my dad's old model railway books talking about using crumpled tinfoil to create rock faces.
I took a sheet of tinfoil and scrunched it into a tight ball. I then rolled the ball around on the sheet of foam, pressing it into the surface. The effect was remarkably similar to that produced by using the rock samples, but much easier and less time consuming to do.
I then used the same painting techniques as I used on the sample piece; dark grey (Payne's grey) base coat, mid grey drybrush and then a light ivory highlight.
|The completed piece|
|Close up detail.|
|Stack of XPS sheets glued to MDF squares.|
|"YOU SHALL NOT... oh, alright then, off you go."|
With the success of this piece I decided to try experimenting some more, and have started doing a few "character" pieces. The one below is a mix of cobblestones and slabs. AGG suggested that the cobblestones could be painted as a mosaic or even use different colours to reflect the use of reclaimed stones.