You know that exciting moment: you finish a batch, start rinsing the stones, and your eyes light up at that glossy, underwater look. Then, sometimes, the stones dry, the gloss fades, and you are left with a matte or hazy finish. Here’s why it happens and how to fix it.
Wet stones always look polished
Water fills in tiny scratches and makes any stone look shiny. The real test is a dry stone. Rinse a few, let them dry completely, and look at them under good light before you decide a step is done.
The most common causes
- Not enough time: the most common cause. If the coarse step left pits or rough spots, no amount of polishing will hide them. Give each step the time it needs.
- Leftover coarse grit: a single grain of coarse grit in the polish step can haze a whole batch. Scrub the stones, barrel and lid between every step, and use a separate polish barrel if you have one.
- Stones beating each other up: mixing hard and soft stones bruises the softer ones. Tumble stones of similar hardness together.
- A light load: a barrel that is too empty lets stones crash into each other. Fill it two-thirds to three-quarters full, and add plastic pellets in the pre-polish and polish steps.
- Stones that won’t take a polish: some porous, grainy or very soft stones never get a glassy shine, however long you run them.
How to fix a hazy batch
- Check the stones dry. If any still have pits or scratches, send them back to the coarse or medium step.
- Clean everything: stones, barrel, lid and any filler.
- Rerun the pre-polish step with fresh grit and plastic pellets.
- Run the final polish again with fresh aluminum oxide.
Good media takes one more variable off the table. Our grit kits use graded silicon carbide and aluminum oxide polish, so every step starts with fresh, consistent grit.
For more help, read how to tell when a tumbling step is done and the common problems in our four-step rotary guide.