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Problems with Rock Tumbling & Polishing

Polishing rocks is an enjoyable hobby for many people both young and old. The basic steps of rock polishing with a tumbler are simple as long as they are closely followed. Most problems that occur in rock polishing are due to lack of attention as well as lack of knowledge. Rock polishing problems can easily be avoided by paying attention to not only the major steps involved in using a rock tumbler but to the steps involved in caring for the tumbler as well as the rocks. Knowing more about the rocks that you tumble will also lead to a successful batch of polished rocks.

Rock Knowledge
- Rocks come in various shapes and sizes and are made up of different materials. The type of rock you choose to polish will impact how the rock looks once it has gone through the polishing process. Before you decide to add a rock to your tumbling batch, check the hardness of it. The harder the rock is, the more polished it will look after the polishing process. Use a knife to determine the hardness of a rock by running the knife over the rock. The harder the rock, the less of a scratch the knife will leave. After you measure the hardness of the rocks, tumble similarly hard rocks together. By tumbling rocks of equal hardness together, you will prevent harder rocks from destroying softer rocks.
Contamination
- Various grit sizes are used for each stage of rock tumbling. Coarser grits are used in the beginning rock tumbling stages and finer grits are used at the finishing stage of polish. After each step is completed, everything must be cleaned thoroughly. The tumbler barrel or bowl must be completely free of grit. The rocks must also be washed completely free of grit. Failure to do this will cause contamination in other steps. When contamination occurs, rocks will not polish and will become scratched. Just one piece of grit can ruin an entire batch of rocks. After each step in the rock tumbling process, clean everything with warm, soapy water. For the final polishing stage in the process, consider using a completely different barrel or bowl than the barrel or bowl that is used with grit. Using a different barrel or bowl for the polishing stage will ensure that the batch of rocks will not get contaminated during the final stage.
Patience
- Rock polishing is not a quick process. The rock polishing process can take up to 6 weeks depending on what type of tumbler you are using. Avoid cutting the process short. Allow the tumbler to run the full course in order to ensure that your batch of rocks is going completely through the tumbling process.
Neglect
- Although rock tumblers must run for days, that does not mean you should not check on them. In the beginning stages, check the tumbler to make sure that gas is not building up in the barrel from the rocks. A buildup of gas can result in a broken rock tumbler. Check the rock tumbler to ensure that the grit and water mixture is staying at a creamy consistency. A thick mixture will result in a poor-quality finished product. Ensure that the barrel of the tumbler is always at least two-thirds full. Adding plastic pellets or river pebbles to the barrel will help keep the barrel at the desired fullness.

Rocks & Minerals