Stage readiness guide
When Are Rocks Ready for Stage 2?
Use shape, pits, fractures and dry surface condition—not a seven-day timer—to decide which stones should leave coarse grit.
Stage 2 cannot fix a Stage 1 decision
Medium grit refines the coarse scratch pattern. It does not efficiently reshape a sharp corner or erase a deep pit. Moving a stone forward too early usually means either living with the defect or sending the stone backward later and repeating multiple stages.
The Stage 2 readiness checklist
| Check | Ready for Stage 2 | Stay in Stage 1 |
|---|---|---|
| Overall shape | Rounded or intentionally shaped the way you want | Sharp corners or flat angular faces still need removal |
| Pits | Remaining pits are intentional or too deep to chase | Shallow unwanted pits are still practical to grind away |
| Cracks | No unstable fractures likely to shed pieces | Fresh or deep cracks may break and contaminate later stages |
| Bruising | No new pale impact marks | Fresh bruises mean the barrel mechanics still need correction |
| Texture | Uniform coarse-ground surface appropriate for the material | Weathered rind, saw marks or rough zones remain |
Dry inspection matters
A wet coarse-ground stone can look far smoother than it really is. Dry every candidate completely, then rotate it under strong light. Surface depressions, fracture lines and bruising become much easier to see. A magnifier is useful for small cavities that can trap grit.
Do all stones in the barrel have to advance together?
No. One of the biggest improvements a beginner can make is to stop treating a barrel as one inseparable batch. Move only ready stones forward. Hold them clean and dry until you have enough similar material to create a correctly filled Stage 2 load. Repeat Stage 1 with the rest.
What if removing finished stones leaves Stage 1 underfilled?
Add new compatible rough or appropriate media to restore working volume. Do not keep finished stones in coarse grit merely to make the barrel full; every extra coarse cycle removes material you already decided you wanted to keep.
What if the pits are tiny?
Decide whether they are a cosmetic feature or a contamination risk. Tiny shallow pits can sometimes remain without ruining the finished stone, but open cavities can trap coarse grit and release it later. If a cavity will remain, clean it carefully before every finer stage.
What Stage 2 should accomplish
Once the stone enters medium grit, the goal changes. You are no longer deciding the fundamental shape. You are refining the deep scratch pattern left by coarse grit into a finer, more uniform surface. That makes Stage 2 more predictable than Stage 1—provided the coarse work was actually finished.
Build a clean Stage 2 load
- Scrub the barrel, lid, rim and stones so no coarse particles remain.
- Use clean media; plastic pellets should remain dedicated to their grit stage.
- Restore lost volume because Stage 1 made the stones smaller.
- Use the medium abrasive called for by your process rather than adding polish early.
- Record the starting date and inspect the dry surface at the end of the run.