Smurfmacaw
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- Aug 12, 2015
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Just received a box of finger stones from Jon at JKI and wanted to relate my experience.
Background
My first Japanese knife was a 185mm Shigefusa Kitaeji. Lots of research led me to the knife and I really like it. It's been through a lot, inexpert attempts at sharpening it, cleaning with Barkeeps friend etc. A number of J-knives later, it's still my go to in the kitchen because it stays screaming sharp, cuts really well and just suits me. I recently had it thinned and as you can guess it just didn't have the kitaeji look any more. Since owning these knives has become kind of a hobby I decided to learn to sharpen on something other than an edge pro and frankly have decided I like sharpening knives on water stones.
Wanting it to regain its former good looks I started researching the finish on the kitaeji's and read/viewed Maksim's treatises on the subject and decided I wanted to try to refurbish the knife (and others) myself.
Current
Some conversations with Jon on this site indicated that he actually sells finger stones and I actually wouldn't have to spend $800 on a Uchigamori just to break it up with a hammer and chisel (Yay!). I ordered the stones and was extremely pleased with the product (at his recommendation I got the harder stones -hazuya). Already flattened on one side and of decent size and maybe 3-4mm thick. The thick stones as sent are fine for properly flattened single bevel knives but since I'm going to be working on the sides of a somewhat convex ground knife I needed to take the next step - I didn't want to flatten the sides of the knife completely as I'm not sure exactly how thick the Damascus cladding is.
Jon sends the proper tissue paper for making the really thin flexible fingerstones suitable for this job to I chose one of the thinner stones and began to thin it. I used a flattened 500 grit shapton glass stone to do the initial thinning and found the thinning to be quite easy and not nearly as intimidating as I thought it was going to be. It was a simple matter of about 10 minutes to achieve a consistent 1mm thickness. At this point I dried the stone and made sure it was clean. I don't have any of the Japanese traditional glue that would be used by a sword polisher so I compromised and used West Systems 5 min epoxy. I chose it because it remains flexible due to the fillers used to make it a 50:50 mix (West Systems standard epoxies are a 4:1 mix and substantially harder and probably wouldn't allow the fracturing of the stone required to make it flexible.) After it had cured for about an hour, I continued to thin the stone on the 500 grit shapton until it was 0.6mm (stone thickness so I had to add the thickness of the tissue). Then I switched to the 2000 grit Gesshin stone until it was about 0.55mm (I wanted to make sure there was no larger grits embedded in the stone). Finally I finished it on my only natural stone (takashima awasedo) to ensure there was no synthetic grits to scratch the knife.
To prepare the knife I used wet or dry sandpaper 220 - 2000 grit to polish the blade and make it smooth. It looked good but not the original finish.
Now I cut the stone into pieces about the size of the pad of my finger which turned out to be quite easy if I first scored it with a single edge razor blade and then snapped it over a popsicle stick. Then I trimmed it to a nice shape and scored it in a 1mm checkerboard (approximately) and then used the back of a spoon to fracture it into tiny squares attached to the tissue. Worked perfectly!
Now for the fun. Using a minimal amount of water I found that beginning lengthwise strokes about an inch long with medium pressure would generate some mud pretty quickly. Once over the blade with medium pressure and then repeated passes with each being less and less pressure until finally I'm playing in the mud with barely any pressure at all. 15 minutes per side using only enough water to keep the mud from drying out (Jon gave me great directions and I combined that with Maksim's treatise to try this out).
Results were essentially perfect. The finish might be very slightly darker than the factory finish but I found it pretty easy by using very light pressure to get a nice even misty finish with alternating layers polished and misty. Maybe not quite as glassy smooth as Shigafusa's but they may be using a finer stone or it could just be my amateur technique. Overall my Gyuto is pretty much indistinguishable from a new one and I'm very satisfied.
Take aways
Fingerstones are not hard to make or use really. I found one stone the size of my finger pad at .5mm thickness to be enough to completely finish the 185mm Gyuto. Total time to do the refinish:
1. Polish knife with sandpaper 220-2000 grit ~1 hour (it had some pretty deep scratches). I might have gotten a glassier finish in the end if I had gone to a higher grit but am not sure.
2. Thin stone from out of the box to 1mm - 10 minutes
3. Glue on the tissue - depends on your glue but I gave it an hour....but that is passive time that I used to touch up the edges of my other knives
4. Finish thinning the finger stone and cut to size - 10 minutes
5. Score and break the stone - 5 minutes
6. Finish the knife - 30 minutes
I also found that using the thinned, flexible stone works even better on a single bevel knife than the larger fingerstone pieces. If you use the larger ones, any minor low spots reveal themselves and take a while to work out with just the mud touching them (as opposed to the stone riding on the mud directly on the steel). I put an awesome kasumi finish on my Suisen Usuba in about 15 minutes or less. Well polished hagane and misty highly contrasting jigane. Easy peasy.
Bottom line - there is nothing hard about this. I'm a total amateur and managed to get good results my very first time with a little care.
Sorry no pics at the moment - I don't have anything other than my iPhone to take pics with but I'll see what I can do next time.
Thanks to Jon for the advice and the super high quality finger stones and to Maksim for the videos and other descriptions.
Hope someone finds this useful.
cheers
Mike
Background
My first Japanese knife was a 185mm Shigefusa Kitaeji. Lots of research led me to the knife and I really like it. It's been through a lot, inexpert attempts at sharpening it, cleaning with Barkeeps friend etc. A number of J-knives later, it's still my go to in the kitchen because it stays screaming sharp, cuts really well and just suits me. I recently had it thinned and as you can guess it just didn't have the kitaeji look any more. Since owning these knives has become kind of a hobby I decided to learn to sharpen on something other than an edge pro and frankly have decided I like sharpening knives on water stones.
Wanting it to regain its former good looks I started researching the finish on the kitaeji's and read/viewed Maksim's treatises on the subject and decided I wanted to try to refurbish the knife (and others) myself.
Current
Some conversations with Jon on this site indicated that he actually sells finger stones and I actually wouldn't have to spend $800 on a Uchigamori just to break it up with a hammer and chisel (Yay!). I ordered the stones and was extremely pleased with the product (at his recommendation I got the harder stones -hazuya). Already flattened on one side and of decent size and maybe 3-4mm thick. The thick stones as sent are fine for properly flattened single bevel knives but since I'm going to be working on the sides of a somewhat convex ground knife I needed to take the next step - I didn't want to flatten the sides of the knife completely as I'm not sure exactly how thick the Damascus cladding is.
Jon sends the proper tissue paper for making the really thin flexible fingerstones suitable for this job to I chose one of the thinner stones and began to thin it. I used a flattened 500 grit shapton glass stone to do the initial thinning and found the thinning to be quite easy and not nearly as intimidating as I thought it was going to be. It was a simple matter of about 10 minutes to achieve a consistent 1mm thickness. At this point I dried the stone and made sure it was clean. I don't have any of the Japanese traditional glue that would be used by a sword polisher so I compromised and used West Systems 5 min epoxy. I chose it because it remains flexible due to the fillers used to make it a 50:50 mix (West Systems standard epoxies are a 4:1 mix and substantially harder and probably wouldn't allow the fracturing of the stone required to make it flexible.) After it had cured for about an hour, I continued to thin the stone on the 500 grit shapton until it was 0.6mm (stone thickness so I had to add the thickness of the tissue). Then I switched to the 2000 grit Gesshin stone until it was about 0.55mm (I wanted to make sure there was no larger grits embedded in the stone). Finally I finished it on my only natural stone (takashima awasedo) to ensure there was no synthetic grits to scratch the knife.
To prepare the knife I used wet or dry sandpaper 220 - 2000 grit to polish the blade and make it smooth. It looked good but not the original finish.
Now I cut the stone into pieces about the size of the pad of my finger which turned out to be quite easy if I first scored it with a single edge razor blade and then snapped it over a popsicle stick. Then I trimmed it to a nice shape and scored it in a 1mm checkerboard (approximately) and then used the back of a spoon to fracture it into tiny squares attached to the tissue. Worked perfectly!
Now for the fun. Using a minimal amount of water I found that beginning lengthwise strokes about an inch long with medium pressure would generate some mud pretty quickly. Once over the blade with medium pressure and then repeated passes with each being less and less pressure until finally I'm playing in the mud with barely any pressure at all. 15 minutes per side using only enough water to keep the mud from drying out (Jon gave me great directions and I combined that with Maksim's treatise to try this out).
Results were essentially perfect. The finish might be very slightly darker than the factory finish but I found it pretty easy by using very light pressure to get a nice even misty finish with alternating layers polished and misty. Maybe not quite as glassy smooth as Shigafusa's but they may be using a finer stone or it could just be my amateur technique. Overall my Gyuto is pretty much indistinguishable from a new one and I'm very satisfied.
Take aways
Fingerstones are not hard to make or use really. I found one stone the size of my finger pad at .5mm thickness to be enough to completely finish the 185mm Gyuto. Total time to do the refinish:
1. Polish knife with sandpaper 220-2000 grit ~1 hour (it had some pretty deep scratches). I might have gotten a glassier finish in the end if I had gone to a higher grit but am not sure.
2. Thin stone from out of the box to 1mm - 10 minutes
3. Glue on the tissue - depends on your glue but I gave it an hour....but that is passive time that I used to touch up the edges of my other knives
4. Finish thinning the finger stone and cut to size - 10 minutes
5. Score and break the stone - 5 minutes
6. Finish the knife - 30 minutes
I also found that using the thinned, flexible stone works even better on a single bevel knife than the larger fingerstone pieces. If you use the larger ones, any minor low spots reveal themselves and take a while to work out with just the mud touching them (as opposed to the stone riding on the mud directly on the steel). I put an awesome kasumi finish on my Suisen Usuba in about 15 minutes or less. Well polished hagane and misty highly contrasting jigane. Easy peasy.
Bottom line - there is nothing hard about this. I'm a total amateur and managed to get good results my very first time with a little care.
Sorry no pics at the moment - I don't have anything other than my iPhone to take pics with but I'll see what I can do next time.
Thanks to Jon for the advice and the super high quality finger stones and to Maksim for the videos and other descriptions.
Hope someone finds this useful.
cheers
Mike
