How to create convincing corners with Plasticard

Plasticard, aka Styrene sheet, is a great material for making buildings but just glueing sheets together can leave you with ugly corners. This article looks at two techniques for creating realistic outward facing corner seams or quoins as they’re known.

With patterns for most types of common construction material, from brick to stone to wood to tiles, plasticard is a low cost, popular and relatively easy material with which to make model buildings for dioramas, war game mats or model railways. I use it for some of the buildings I sell the MRE store.

The sheets come in standard sizes and it’s usually just a matter of cutting them to the required size and shape, carving out the holes for windows and doors and then gluing them together with plastic cement.

Well, that’s the theory.

Real-world, prototype, stone and brick walls have cornerstones that are cut so they span corners and hold the two facing walls together rather than just leaving them to butting up against one another. In doing so, the bonds (the horizontal pattern) ‘flow’ around the corner as seen in this photo:

Yet when mating plastic card sheets together, the stones just end at the corner (in real life this would result in a weak building with the walls prone to separating and falling down). Even worse, a line is left down the middle where the two sheets meet. This looks ugly and spoils the look.

Just recently I shared some photos of a mill house I’m scratch building from Wills kits on the MRE community group and several members asked how I did my corners.

Here are two techniques I use. This is not saying these are the best or easiest, they are just what I use and seem to give okay results.

The fill-and-file technique

What you’ll need

• A precision knife with a new blade
• Glue, plastic cement with a precision needle point dispenser, such as this one that you can make yourself
• Plasticard sheeting of your chosen material, stone, rough stone, brick etc.
• Magnetic snaps
• Plastic putty
• Liquid Green Stuff (for internal Quoines)
• Small files; flat and triangular

If you’re pushed for time, not familiar with the properties of Plasticard and how it behaves or have two sheets to join at a corner this is the technique I’d suggest using.

First, find two pieces of the brick or stone pattern card where the courses match along the edge. The horizontal mortar lines should align between the two sheets. This can take some finding aren’t obvious on the rough stone Plasticard I work with most and you may have to try several sheets or line up an edge on one piece with the pattern further into the sheet on another to find where they align.

With two matching pieces, mitre the edges to form a 90 degree join and glue them together with plastic cement. Use a precision applicator so as not to spill or drip glue onto the pattern. I use magnetic snaps to hold the sections in place while the glue sets.

Once dry, take a look at the edge and use plastic putty to fill in any gaps or spaces where the pieces meet and indentations where the stone or brick should curve around. Deposit a tiny amount over the holes and then smooth it off with a wipe of the finger. If you get any into the mortar seams, use the point of your knife or a small flat-headed screwdriver to scrape it out. For inner corners, Liquid Green Stuff may be easier to apply. Just brush it into the corner and wipe the excess off. You may need to apply several layers to build up the height.

The putty dries fast and once set, take a small file and file away the edge so the corner of each brick and stone course has a gently rounded appearance, making it look like a single stone has been used. You might also need to carve away any putty that has crept into the mortar line at the corners using a triangular file.

If there are any dips or unsightly edges, repeat the process until the corner is rounded to the shape of the brick or stone.

Bending plasticard

Tools/Accessories needed:

• A precision knife with a new blade
• Plasticard sheeting of your chosen material, stone, rough stone, brick etc.
• A heat source, lighter, matches, hot air gun, etc.
• Ideally, long nose pliers

The above technique works but is fiddly and time-consuming whereas the next approach is quicker and can produce nicer results but takes practice as its easy to snap the styrene in the process. It’s the ideal technique when making a corner in the middle of a single sheet. If you need a corner where two sheets meet, try the above technique or join them together as a long flat piece and then use this approach.

Essentially, this technique involves bending the sheet where you want the corner to be so there’s no joint line as can be seen in the photo montage above.

On the non-patterned side, score a V into the material to about half wave through – do NOT cut through it – as per the photo in the top left.

Now the tricky part.

Use a heat source and gently warm the non-pattern side. I use a lighter or hot air gun. Alternatively, dip the plasticard into near boiling water until it’s flexible. (If doing this. please take precautions not to burn yourself).

If it starts to melt, you’ve gone too far. I recommend experimenting with it on a spare piece of plasticard first to determine how much and how long you need to heat it so its soft enough to bend but doesn’t melt.

Once warm, gently bend it to 90 degrees (or to the angle desired).  You might have to apply the heat several times during the process.

Don’t worry if the other side goes white as it stretches; this is normal and the white won’t be visible once it’s painted (as seen in the top photo of this article).

If you notice it start to crack, back off, apply more heat and try again. If it does crack, don’t worry, you can fill in the crack with the putty or Liquid Green Stuff used in the first technique.

Holding the card with long nose pliers on either side of the score line and using them to bend the card helps ensure the bend goes along the cut line.

And that’s it.

I’d recommend you experiment a little before working on an actual model as it took me quite a few practice runs to get a finish I was happy with, code for I ruined the first models! 🙂

If you have some spare styrene sheet lying, perhaps some old offcuts, try both techniques out and come back here and tell us how you got in.

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