How will you glue it down, Ed? Mist? Pipette? I thought you stated somewhere else that you were now applying glue first, then sprinkling the grout onto that.
I love the look, and would like to do something similar for my 1950s yard. Period photos show a much blacker look on the C&NW. I assume a lot of cinders.
One other question: What happens when you use grout and glue, and eventually have to replace a turnout? That's what scares me. I know from experience that ballast can be loosened with water, but I'm afraid a grout-glue mix would be more like concrete.
Jim