hink its supposed to be rock and roll.... any way was on good ole you tube today and found this neat idea to make light weight rock <!-- m --><a class="postlink" href="https://www.youtube.com/watch?v=PGknDkl-B1Q">https://www.youtube.com/watch?v=PGknDkl-B1Q</a><!-- m -->

Been using that for several years now ...get the scraps free from an upholstery shop .

Was used on the Model Railroader office layout quarry branch project about five years ago.

Nice. I hadn't seen that before.