Tips how to use and maintain your new natural stone:
1. Always keep your natural stone clean. Try to keep the surface from getting contaminated with dirt and dust.
2. Keep your natural stone flat.
3. Flatten your natural stone with a diamond plate like a DMT or ATOMA. You can also use sandpaper mounted on a flat surface like a piece of plate glass, but use another natural stone for final flattening. The surface needs to be as smooth as possible. If you do not have another natural stone to smooth your stone, use a Tomo nagura or any natural nagura you have.
4. It is very important to rinse off your natural stone very well after flattening with clean water only, as residual abrasives from your flattening source might scratch your knife if not washed away. Do not use water that has been in contact with synthetic stones.
5. When sharpening or polishing a knife or razor, use as little water as possible to create mud. Just a drop of water from your fingertip is enough for harder stones and more water on softer stones. The mud should be in the form of a paste. Always use mud when polishing or sharpening with natural stones. Using natural stones without mud will not give the best results. On very hard naturals for razors, it can be good to use with only water during the last honing.
6. Always rinse your knife or razor well with clean water only before and after sharpening.
7. Use a nagura or other natural stone to make mud on harder stones or they might scratch the soft iron (jighane) on your knife or Kamisori razors.
8. Lacquer your stone on the sides and the bottom to reinforce it. If a stone has a crack, glue it to a wooden base to prevent the crack getting wider. Cracks can also be stopped with super glue.
9. Use small soft stones finger stones on a soft iron (jigane) and harder finger stones on a hard steel (hagane). If a knife is made of mono-steel, or it is a Honyaki knife, softer stones might be better.
10. Do not expose your natural stone to freezing temperatures and do not leave it out to dry on a very cold day or night. Do not expose your natural stone to direct sunlight. Either of these extremes of cold or heat could crack your natural stone.
11. Make grooves in your nagura to help make a slurry easier and to help with any sticking problems.
12. Glue thin stones to a wooden base so they will have support and will be harder to break or crack in half.
13. If using artificial/synthetic stones to set a bevel, use 500-6000 grit stones first, then carefully rinse off any of the artificial/synthetic residue that may be on your blade with clean water before final honing on a hard Japanese natural stone with nagura.
14. The room for your final polish or honing should be clean! Dust and stone powder on stones is your enemy! For final polishing it is VERY important to keep everything very clean and use only clean water! If your water source contains a lot of minerals, distilled water or spring water may be better to use.
How to flatten natural stones
For knife users:
The natural stone you are using to sharpen a knife is not as hard as a stone used for razors. Stones with a hardness of lv 2 to lv 3,5 work very well for knives. I actually do not flatten my stones for sharpening knives that often. I try to wear the natural stone evenly using all parts of the stone when I sharpen. Knives do not really need a 100% flat stone except for "ura" on back side for single beveled knifes, but I use hard stone for this :)
For razor users:
It is very important that your hard natural finishing stone is very flat and very smooth too. Softer stones like lv 3,5 or 4 do not need that much smoothness because they are soft and are usually used as pre-polishers. They will make mud very easy and will remove scratches from from lower grit stones on the blade. For very hard stones like 4,5 or 5, it is very important that your stone is as smooth as possible! Very hard stones can chip your razor blade. If there are large loose stone particles on the surface of your natural stone, they can cause big scratches, so the smoother you hard stone is the finer it is too :)
How to smooth your natural stone:
Flatten your natural stone with a DMT (120 or 325) or Atoma (140). Sandpaper can also be used, it does not matter. Make sure to finish with highest grit possible. Smooth your natural stone with a higher grit 6-8K, or even 10K stone. A nagura or other natural stone can also be used. Your stone has to be like a mirror when it is dry and has some reflection when you look at the surface at the right angle. Small holes or big single scratches are OK, they do not affect sharpening that much, so do not bother to flatten them out :)
3 stone flattening is most recommended flattening system for Jnats
Flattening and smoothening with Atoma