When I created a road on my larger HO layout (which is only 4x6!) I remember using wood filler or something similar to create a road surface. I've now just started building a very small HO layout (about 3x4!!) that I plan to use as a portable layout for my smaller trains. I have some wood filler and was thinking of using that for a road surface. I'd simply apply it and then sand it down. After that, I'd cover or paint the surface with some Woodland Scenics Top Coat. Is wood filler OK to use? Thanks, R.