Foam board surfaces

[adriank]

I'm about to start modelling stone railway structures in 4mm scale. I have read Chris Pilton's book on cottage modelling for Pendon and David Wright's book on making rural buildings. The former uses relatively thin card and the latter 3mm foam board covered with DAS clay. I've experimented using card with a thin coating of ready-mixed plaster. The plaster adhered well without glue even when the card was flexed after its application. It was also easy to scribe and took washes and inks well. I found it more difficult to make an impression on plain card.

 

However, I like the idea of using foam board since it would make for a more rigid structure but am curious about the different surfaces - paper vs pvc - and their suitability for various renderings: DAS, plaster, watercolour, artists oils and acrylics.

 

I'd be grateful for any advice.

 

Adrian

[john new]

The one definitely not to use long term for a base plate or stiffening piece is the plastic sheeting used on for sale boards, event posters and the like. (Cellotex?) I was given some event poster boards after they were taken down, it lasted a while after I had used it as base plates but then the message layer peeled off the white plastic layer. 
 

A similar issue with some large sheets of card faced sandwich foam board. Used to back some 1:1 size replica SLS tour headboards for a display stand they also peeled after a period of time.
 

Not necessarily relevant if used in small pieces but a problem perhaps in buildings of a larger size or as the base in a diorama.

 

Edited July 6 by john new
Added the cellotex name.

[luke the train spotter]

I've found that foamboard and Das clay works really well for me, especially on larger structures. Whilst card can definitely be cheaper I've found that it can warp much easier which can make it frustrating when trying to get a flat finish. It sounds like you have already experimented a bit but I'd recommend doing a couple more test pieces before committing to a structure. On a side note I find that das clay takes paint much better, sometimes after a couple of washes paster can soften and ever so slightly loose the definition scribed into it. 

 

You might be set on scratch building a certain prototype but I'd recommend using a laser cut mdf shell where possible, saves you the work of cutting out windows and gives you the thickness of card with the rigidity and strength of foamboard. Fair price models on ebay are a good source for these (see below my best attempt at scribed stonework so far using a laser cut mdf shell with das clay painted with acrylics).