QUOTE(wunderlich @ Jul 22 2007, 06:12 AM)

Hi folks,
because I have to polish some softmetalwork recently I tried a traditional japanese charcoal polishing procedure. The result was not mirrorlike, rather matt.
I want to collect information on this subject into this tread. There are information on sword polishing obtainable on different sources but very less for polishing soft metals.
The use of toishi (whetstones) is shown
Here I found two short Quicktime movies showing a nuri-shi while polishing.
The first stage is stone polishing
Ishitogi followed by charcoal polishing
SumitogiMy question is which kind of charcoal is used best when traditional
roiro sumi is not available?
Perhaps some of the members here have some experiences about that.
regards
Karl

Hi Karl,
I use this procedure as part of my living, but I learned it from Ford and I use supplies that he provided me with. So I have not had to purchase any myself... yet. I have two grades of Ho wood Charcoal. One has the more gentle polishing action than the other and they are used in succession. The Final stage is powdered charcoal used with a Migaki brush. It is not just up to the grade of abrasive though. I find that pressure is also important. Working a given pressure with a particular stage followed by a pass with lighter pressure will yield a higher grade finish. I believe that all the charcoal products are available for purchase in Japan. Ford is the one to ask where to get these supplies.
I probably would not have looked for alternatives until I ran out of my current stock. I have the wood specie names though and if you could not find the charcoal you might be able to buy the wood. Making charcoal is simple. I don't know which specie the powdered charcoal is made from, but I would guess it is the softer variety mentioned and the Brush allows it to work with a gentler action for a finer finish.
Honestly I use Graded abrasive powder with a brush as an alternative to the powdered charcoal. The Powdered charcoal that Ford gave me is still pretty scratchy for some reason. That could just be my inexperience though. I do get good results with Silicon carbide powders used the same way. "1,000 mesh size" used with a Migakebaki yields a fairly good final polish. You can keep going finer and finer until you achieve the result you are looking for. I find it difficult to see much improvement beyond 1500 mesh size. You can find these powders through places that sell rock tumbling/polishing supplies.
regards,
Patrick