I've found a source for crushed walnut shells that I can use for live coal loads in my operations. I've tested dyeing the shells with good results. I originally tested with Woodland Scenics coarse black ballast and it works great in my application. Just not sure what mesh size it is so I can compare a bulk buy versus many many Woodland Scenic containers. Any ideas on mesh size of Woodland Scenic fine medium and coarse ballast ? --- Ken