Ebay will be a good source for most all polishing supplies. There are several kanahada mixes listed. The book I recommended above has all the mixing and use info for the traditional polishes.
As to what works for what steel, that is why you want a kit of several polish powders. Different ones work on different steel and even the same steel may vary depending on the hamon type and the HT.
The traditional kanahada is made from finely powdered steel scale ( black iron oxide). The old guys make it by burning thin steel snippets in a oven/forge. Then they grind it in a mortar, sieve it to a fine powder, and mix with oil. They have special papers they use to filter it for use. They filter it though layers of filters so only the very finest oxides get used.
I use a Western alternative using purchased powder - I mix with the oil to a slurry, put a teaspoon of the oil/powder mix on a stack of three or four small coffee filters. Set the stack over a glass petri dish and let it seep through. When doing the kanahada polish, lift the stack and touch your CLEAN fingertip to the bottom of the stack. That will give you a dab of the filtered polish.
However, unless you at a dedicated traditionalist, buying a bag of fine powder, or a small bottle of the prepared polish mix, from eBay is far simpler.
A kit with a small bottle of choji oil ( or any non-rancid type oil) and five or six powders will do most any polish.
Here is what is in my togi kit:
Choji oil, denatured alcohol, acetone.
Assorted grit 3X10" DMT diamond stones and some other special sharpening/shaping stones. Each is stored in a heavy Zip-lock freezer bag.
About a dozen water stones and a pond tray. Each stored in its box and in a freezer bag.
Finger stones - hazuya and jizuya ( I rarely use these).
Various grits of high grade SC papers. They go from 220 grit to 2500 grit. They are all cut into 2X2" squares, and stored in labeled Zip-lock plastic bags.
Cut up pieces of 3M polishing papers ( really a fiber cloth). These go from green/400 to white/8000.
Covered Oke for clean water.
Various labeled bags and tubes of polishing powders and compounds. Each is in a plastic bag or bottle/tube and stored inside a second labeled zip-lock bags:
Flitz
Mother's polishes
Simichrome
Assorted grits of silicon carbide up to as fine as you can get. 800, 1500, 2500, 4000, 8000 are all good.
Assorted diamond polishing compound. It comes in syringes, usually color coded from 325 grit to 100,000 grit. The most useful for polishing a blade are 600, 1200, 3000, 8000.
Rouge ( red iron oxide) AKA red kanahada
Black rouge (burnt iron oxide that will leave a dark surface in polishing) AKA black kanahada
Magnetite powder (burnt black iron oxide) AKA jitekko or shashikomi
Chrome oxide AKA Aoko
Tin oxide
Aluminum oxide
Linde A
Linde B
I use covered petri dishes and domed glass discs for filtering, mixing, and applying the polish slurries. The domes discs are a variety of things I have found for free or super cheap domes like pocket watch crystals, and laboratory glass filtration discs. You can buy pocket watch crystals at $10 for 50-100 on ebay. If you know an old watchmaker, he will likely give you all you can ever use for free. I got a cabinet filled with about 5,000 for $20. I kept the 20 drawer cabinet and a few rolls of 100 and gave the rest of the crystals to a watchmaker friend.
I also have an uchiko ball that I rarely use. ( unless someone is watching
)
A roll of soft disposable paper towels. Get the best and softest brand available, as it will likely have less grit in the paper. Store it in a large zip-lock bag.
A tube/roll of makeup removal pads. These are perfect for applying and working the polishes. They are soft fiber material and just the right size for finger polishing.
Most of this is stored in two big tool/hobby/fishing boxes with clear plastic tops and lots of internal storage.
Use all sanding/polishing papers and polishing/cleaning supplies like they were free ... especially paper towels used to wipe things down. Trying to get more like from them, or re-using them is not a good idea.
