This is partly inspired by a Youtube video I watched some weeks ago where a guy made some post-apocalyptic terrain pieces using a similar method. I've made a few test models and tweaked it to suit my 28mm WW2 collection. I've seen gaming tables in the past where the gamers have spent hours placing rocks and rubble - and while this provides great detail, it's just not practical for club games that are only played over a shorter time span. These here are made as individual piles, so you can just place or lift them fairly quickly. Something else to add, is the extremely low cost of what I've outlined here. It literally costs pennies for dozens of these terrain pieces, and i hope you'll agree, they look great.
You will need:
A roll of kitchen foil.
A can of black spray paint.
A can of brown spray paint.
Some acrylic light brown paint for drybrushing.
Some ink wash (either GW Agrax Earthshade, Nuln oil, Vallejo Sepia Immersion Dip or similar).
A bag of grit/rocks.
Some small mdf off-cuts, and/or some MDF 'bags of bricks' from Charlie Foxtrot models.
First rip off a length of tin foil and crush it into shape on a flat work surface. Make sure you do it really tight and compact.
If you're making rubble piles that lay against walls, then push the tinfoil into a right angle. Here I'm using the angle between the kitchen work surface and wall.
Next 'tuck in' all the thin edges of the tin foil. You don't want them sticking out and folding over etc on your gaming board.
Once you've made a few, spray paint them in matt black. Don't worry too much about little bits of silver still shining through - we'll deal with these later. Tin foil is notoriously light and can blow away while spraying...so pin each one with a bit of blu-tack underneath (small amount).
After the black undercoat has dried, then spray with your choice of brown.
Next, get your wash and an old brush and ink wash each rubble pile. Make sure the paint seeps into all the gaps, as this will hide any more silver not caught by the undercoat or basecoat.
Once this is dry, do a drybrush of your acrylic light brown all over the piles.
Then, get your pva glue and start blobbing it all over the piles. Use as much as you want, but make sure it's enough to hold the scatter you're going to apply next.
Take your mdf off-cuts and start pushing them into the pva glue. I don't bother painting these off-cuts, as they are meant to look like scrap wood anyway.
Then take your mdf bag of bricks and scatter a few of these across the piles too. You can add all sorts of extras if you like - sandbags, barbed wire etc. I've also got a bag of Charlie Foxtrot broken wagon wheels, so I've added one or two of those.
Before the pva dries, take some grit and sprinkle it over the rubble piles. This will fall over anywhere the pva is still exposed.
Leave to dry, and you're done!