I am planning to make a short train tunnel for my layout. I am trying to make it as simply and quickly as possible, for the upcoming visits by grandsons.
Has anybody every made a structure out of cardboard, and then "squirted" foam can insulation on the outside of it?
Will the foam stick or just fall off? Does it make a difference whether you use open cell or closed cell foam?
If it sticks, then will it look anything like mountain rock when it dries and is painted?
If not, is there any other product that will easily stick to cardboard? I don't think paper mache will, and the wet mache would probably just reduce the cardboard to mush.
Thanks for any suggestions.
Mannyrock