Rock Tumbling Grit - Stage 3.5 Pre-Polish 1000 Grit - Silicon Carbide
Our 1,000 grit silicon carbide is a Stage 3.5 pre-polish for rock tumbling, used after fine grit Stage 3 and before final polish Stage 4 to further refine the surface of the stones and prepare them for a brighter, cleaner finish. If you want rocks that are truly ready for polish, this is the stage that helps bridge the gap between smooth and glossy.
A smooth stone is not always ready to polish well. Stage 3.5 is where the surface is refined enough for the final polish to do its job properly.
What Stage 3.5 Pre-Polish Does
Stage 3.5 is the pre-polishing stage. This grit helps:
- Remove the very fine scratches left after Stage 3
- Further refine the surface before final polish
- Improve smoothness and surface consistency
- Help final polish produce a brighter, cleaner shine
- Reduce the risk of haze or leftover marks showing through later
This stage is what takes stones from finely smoothed to properly prepared for final polishing. If the earlier stages were done well, pre-polish helps maximize the final result. If they were rushed, scratches and defects can still carry through.
Best For
Use this pre-polish when you want to:
- Move on from Stage 3 to a better final finish
- Refine stones before Stage 4 polish
- Improve the quality of the final shine
- Get a cleaner, brighter polishing result
- Add an extra finishing step for better-looking stones
Not For
This pre-polish is not for:
- Initial shaping of rough rock
- Removing deep scratches or coarse grinding marks
- Correcting pits, cracks, or sharp edges
- Replacing the earlier grit stages
- Final polishing
- Quick shine improvement on poorly prepared stones
If your rocks still show scratches, flat spots, pits, or surface damage, they usually need more time in the earlier stages before moving to pre-polish.
How to Use It
For most rotary tumbler batches:
- Make sure the rocks are fully cleaned after the previous stage before starting pre-polish
- Clean the barrel thoroughly to avoid grit contamination
- Fill the barrel about 2/3 to 3/4 full
- Add about 1 tablespoon of grit per pound of rock
- Add water until it is just visible among the top layer of stones
- Run the batch, then inspect the stones before moving to final polish
Before advancing, the rocks should be very smooth, evenly refined, and free from visible fine scratching.
How Much Do You Need?
The right size depends on how often you tumble and how many batches you run.
- Sample - 2 oz: good for testing or very small batches
- Small Bottle - 8 oz: good starter size for occasional tumbling
- Medium Bottle - 16 oz: a solid all-around size for regular hobby use
- Large Tub - 32 oz / 3 lb: good value for frequent tumbling
- Bulk Bag - 10 lb or 25 lb: ideal for heavy use, repeat batches, clubs, classrooms, or serious hobbyists
Pre-polish is usually used in smaller amounts than the earlier grit stages, but it can make a big difference in the quality of the final shine.
Why Pre-Polish Matters
Stage 3.5 is what helps prepare stones for their best possible final finish.
This step is often considered optional but if you are looking for maximum shine after your polish step then consider this 1000 grit option.
