Beads, Plops or Rubber Bands?
When tumbling rocks, it is common to use some sort of cushioning material in the polishing stages. This reduces frosting on the edges and may prevent chipping.
A variety of materials can be used for this cushioning. We will focus on three of these in this investigation: Beads, Plops and Rubber Bands.
Beads are small bits of a tough plastic very similar to weed whacker cord. They float in water and as they are convex, they do not stick to surfaces. You can easily seperate beads from the rocks by flooding with water and scooping them off.
Plops are bits of plastic that are somewhat softer than beads and that have a convex and a concave side (manufactured by plopping the material). Because of the concave surface, the plops stick to flat and slightly curved surfaces. This is a hassle during cleanup as though they float in water, you will spend significant time getting 100s of them off the inside of your tumbler barrel. However, because they cling, it might be that a little bit of polish gets into the concave pocket and then rubs on the rocks. Plops might be better than beads in polishing performance.
Rubber bands are another cushioning option. They float in water. They don't have a concave surface and their stranded structure may work even better than the plops concave face in rubbing the polish across the rocks. They might even cause extra tumbling in the drum by cross-linking stones and providing an additional source of rotation.
In this investigation, we will compare beads, plops and rubber bands to see which works best in producing well shined rocks (surface that is unchanged wet or dry), in the least time, with the least hassle.