[Gpa113]

Hi Jeremy,

I have used expanding foam on my fully scenic layout.  It was used for banks, small features and for filling in gaps, large and small, around tunnel areas.

I paid £5 from Wickes for a pretty decent sized can.  Terrific fun, but less is definitely more with this stuff....

Once dried I cut it about as I pleased to get whatever shape I was after. Then covered it in tile grout, let that dry to form a nice tough exterior and finally painted in appropriate colours, scattering different flocks and ballast across before the paint had fully dried.

Worked well, and looks good. Very simple to use, but cleaning the adapter nozel is a real pain.  Easier to just use another if you can get a spare or two.