Jul 11, 2016· filler. This takes up the spaces between the glass pieces. You can use either ceramic media or plastic beads, both of which can be reused. coarse grit. Unlike rock tumbling, which requires coarse grit, fine grit, prepolish, and polish, making sea glass .
Once the bottles leave our yard they go into a press and the plastic bottles are squeezed at extremely high pressure into a big block. If the lids aren't removed the bottles either don't crush down and the blocks fall apart or the pressure caught inside can make the bottles explode.