Dabbling with Depron

Experiments with Depron foam

I had read a few entries on blogs about using foamboard for modelling, and when at the club, I came across a chunk of what appears to be part of an advertising sign for 'Focus' DIY, I thought I'd have a dibble.

The board has a quite a thick covering each side of  printed card which peels off easily leaving pristine white closed cell foam of a type known to model aircraft makers as depron. This isn't crumbly like polystyrene or the usual foamboard, but quite tough and resistant to tearing. It's very easy to cut accurately and can be sanded or edges rounded with the fingers.

I'm sure department and DIY stores, and commercial sign printers throw away mountains of the stuff.
A reasonably cheap source of Depron foam is wood laminate flooring insulation. One trade name is SELITAC available from B&Q I believe.

I made a few test samples including the little stone hut. First thing I learnt, keep it away from normal superglue which eats through the foam like Billy Bunter with a jam doughnut - Apparently, you can get foam safe superglue, but ordinary PVA does the job fine.

Scribing

I tried various scribes, and found that for me, a fine pencil with a rounded point works as well as anything. 

A superfine Sharpie eats slightly into the surface and conveniently leaves a black line, which is handy for fine brickwork with dark mortar. The triangular example in the photograph shows this. 

Clay modelling tools - either metal or plastic - are useful for modelling the surface.

Painting

I've tried a variety of painting methods so far, it's not quite the same as painting DAS covered models as the foam isn't absorbent to most paints, however it does seem to absorb 'Astonish' wood floor polish which leaves it with a harder surface which will accept acrylic and water colour.

You can give it a very light blow over with Halfords acrylic car primer, but you have to go easy as some component in the spray will dissolve the foam. Used sparingly in several light coats, does however, give the foam a nice stoney texture.

Once you have your mortar colour, with a few variations to represent staining, moss etc. adding the stone colour comes next using much the same techniques as with DAS skinned models.

I would expound further on the subject of painting foam, but during my experiments I came across this blog Trainscape which, although in Spanish (Google will attempt to translate) demonstates far better than I ever will, the possibilities of realistic foam modelling.