You will need to fill your barrel 2/3 to 3/4 full of mixed sizes of tumbling rough from 1/4″ up to 1 1/2″. If you don’t have enough rocks to tumble, you can add fillers such as plastic pellets or ceramic media to make up the volume. You will also need to add water to cover the rocks.
For each stage of the tumbling process, you will need a different grit size of tumbling grit. Stage 1 requires a coarse silicon carbide grit. You will need to add approximately 2 tablespoons for a 3lbs barrel size. For your next two stages, you should first add a medium and then a fine grit followed by approximately 2 tablespoons of aluminum oxide polish.