When preparing to tumble, first ready your rocks and tumbler. Thoroughly clean your rocks with lots of water — with some force if possible. We use a washing machine hose with an adjustable nozzle attached to our utility sink. If there are any pits or cracked areas, you can scrub them with an old toothbrush. Also, thoroughly clean the inside of your barrel. A small brush can be used for this also. If you choose to use some soap for your clean up, be sure to rinse thoroughly, as left behind soap will foam and add gas and pressure to your barrel.
When everything is clean place the rocks and filler in your barrel. If you are using plastic pellets as a filler, be sure to use new pellets in your polish step. The grit will wear it's way into these pellets and then contaminate your polish if you use the same pellets in your grit and polish stages. If you are using small stones as filler, they can be used in all of the tumbling stages, just be sure they are cleaned of grit between each cycle.
Mix your polish in a clean container and pour it over your stones so it just covers them. The polish can be of a consistency from milk to cream. Some stones, quartz for example, need the polish thicker while agates need it thinner. After a week of tumbling in the polish cycle, if your stones are not polished to your satisfaction try thickening or thinning your polish, and let it tumble for 4 to 7 more days.
When your stones are finished, pour your polish into a clean container and save it for your next load. Polish is reusable. As long as you clean everything very well before polishing, your polish can last for many loads.
You may use Cerium Oxide or Tin Oxide (see images right) in your tumbler. Tin Oxide may be a little better but not enough to warrant its cost. Cerium Oxide works well for tumbling needs.
We hope this information is helpful to you, and happy tumbling!
The grit on the left is 500 and finer (fine) grit. The grit on the right is Cerium Oxide Polish. The numbers or "range" in the grit is determined by the number of granules per inch if they were placed end to end.
The image on the left has been tumbled with 500(and finer) grit. The image on the right has been polished with Tin Oxide.
The image on the left here is 1000 and finer grit also known as pre-polish. The image on the right is of Tin Oxide, a polish. The white color of the Tin Oxide makes it difficult to see the granular detail.