Polishing, Kasumi Finish & Etching

[pd7077]

Was it better using the Rhino followed by micro mesh, or micro mesh all the way through?

Sandpaper feels as though it is more aggressive than micromesh. If I had sandpaper that that went all the way up to 12k, then I would probably prefer it over the micromesh. One advantage of micromesh is that it is more durable. I swap out pieces of sandpaper like it’s going outnof style, but this particular set of micromesh has lasted through 5 knives so far. I also like using the micromesh as the backing for sandpaper.

[gladius]

Very nicely done.

Having a very polished base prior to fingerstones yields a much different kasumi than a brushed base. While I may not always put this much effort on all of my kasumi finishes, it was very cool to see the differences.

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True also when sharpening an edge. I find if I polish up to at least a 6k edge then move laterally (or down in grit) to a natural finish yields much better results and quicker too.

[milkbaby]

Great work! Just saw your post in the new knife thread and was thinking that's the shiniest Kato I've ever seen and now I understand why.

[fuzion]

Probably a silly question but where do you buy finger stones for polishing? And any alternatives to finger stones? Micromesh?

[Kit Craft]

Probably a silly question but where do you buy finger stones for polishing? And any alternatives to finger stones? Micromesh?

Aframes Tokyo, Watanabe blade, Japanese natural stones and many other places. Some guys buy chunks of stone and make their own.

[pd7077]

+1 to what Kit said. You can also try placing a WTB in the classified section. I’ve gotten some really nice fingerstones from members here.

Micromesh can be found on Amazon.

[gladius]

Probably a silly question but where do you buy finger stones for polishing? And any alternatives to finger stones? Micromesh?

Aframes Tokyo, Watanabe blade, Japanese natural stones and many other places. Some guys buy chunks of stone and make their own.

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Yep, Uchigomori stone, chisel...

http://www.japanesenaturalstones.com/fi ... es-how-to/



The results can be dramatic...

http://www.swordpolisher.com/beforeandafter.html

[pd7077]

I couldn’t help myself. As much as I loved the mirrored finish, I just had to do it

[Lepus]

Woah.

[salemj]

That's great. I've done some major work on a knife and I've been struggling for a few days to clean it up. I think the key is that i need to stop and change a few materials! And also set aside more time...I'm beginning to loose a bit of patience with each session and I think I need to take a break.

I'm curious: is there a reason you dislike vertical scratch patterns on the blade surface? These are "normal" and also seem to help prevent food from sticking. I find horizontal lines are actually much easier to produce, but I've stuck to vertical because it is more normative and I've assumed it had other benefits, especially if I don't go up to such high finishes.

[Kalaeb]

I am with you, I think I like the kasumi over the mirror as well.

[pd7077]

That's great. I've done some major work on a knife and I've been struggling for a few days to clean it up. I think the key is that i need to stop and change a few materials! And also set aside more time...I'm beginning to loose a bit of patience with each session and I think I need to take a break.

I'm curious: is there a reason you dislike vertical scratch patterns on the blade surface? These are "normal" and also seem to help prevent food from sticking. I find horizontal lines are actually much easier to produce, but I've stuck to vertical because it is more normative and I've assumed it had other benefits, especially if I don't go up to such high finishes.

For me, it boils down to two things that are somewhat related. (1) Aesthetics - In my eyes, lines perpendicular to the edge just don't look as appealing as parallel lines. It's not that I looks bad in any way, but my (point #2) OCD just won't allow me to jive with the aesthetics of perpendicular lines. TBH, I haven't really noticed any significant difference in terms of stiction. While I don't deny that surface texture can have an affect on ingredients sticking to the blade, it seems to me like geometry plays a more integral part. If there's anything that I've noticed that is different, it is that cuts seem to feel smoother from the higher degree of polish...but that could just be my mind playing tricks on me. At the end of the day, I'm only a home cook so I have the luxury of taking my time when we cook. I don't have to worry about chugging through pounds and pounds of product so I can afford to just kick back and enjoy the process. A big part of that enjoyment comes from looking down at my board and seeing a pretty knife

The process of polishing is pretty straight-forward. The biggest obstacle that anyone will face is impatience...I lose every time

[Carter]

Looks great Steve....what did you use to "bring down" the finish?

[pd7077]

Looks great Steve....what did you use to "bring down" the finish?

Thanks Carter. I used fingerstones. On that particular knife, I used Shinden kiita followed by Uchigumori.

[Carter]

Well done, thanks for sharing.

[gladius]

For me, it boils down to two things that are somewhat related. (1) Aesthetics - In my eyes, lines perpendicular to the edge just don't look as appealing as parallel lines. It's not that I looks bad in any way, but my (point #2) OCD just won't allow me to jive with the aesthetics of perpendicular lines. TBH, I haven't really noticed any significant difference in terms of stiction. While I don't deny that surface texture can have an affect on ingredients sticking to the blade, it seems to me like geometry plays a more integral part. If there's anything that I've noticed that is different, it is that cuts seem to feel smoother from the higher degree of polish...but that could just be my mind playing tricks on me.

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A higher polish does allow the knife to go through product smoother to a point...I polish the back of the primary edge relieving the shoulders which makes a noticeable difference. A polished finish beyond that up the blade can cause stickage though.

I have observed some texture, whether horizontal, vertical or other does seem to address the stickage problem. Shibata knives put a vertical pattern on their knives that helps food release and Kato (as well as others) also uses a vertical pattern (see comparative photos below).

Shibata first vs Kato

[pd7077]

Thanks for that. I'll try to pay a bit more attention to see if there are any appreciable differences in stickage. In your experience, do you notice if one is better than the other (vertical vs horizontal), or is it simply the presence of any surface texture?

[gladius]

Thanks for that. I'll try to pay a bit more attention to see if there are any appreciable differences in stickage. In your experience, do you notice if one is better than the other (vertical vs horizontal), or is it simply the presence of any surface texture?

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I have not - as long as there is some texture. My Konosuke Ginsan exhibited stickage until I lightly sanded the surface a bit. The vertical texture may be a result of the grinding wheel or maybe a result of careful study...perhaps a question for someone like Takayuki Shibata about the design choice?

The sides of the knife have a rough finish, to minimize friction between the food and the blade. This is especially noticeable with foods that have a high water content. My knife's rough sides break up the water's surface tension, allowing the blade to slide through more easily. --Shibata

[pd7077]

Well, after making some pretty decent strides in kasumi finishes and taking a crack at getting a mirror polish, the next logical step for me was to figure out how to etch/re-etch the hamon on a honyaki. I understand that some people get intimidated by honyakis due to fear of not being able to maintain (or bring back) it’s original finish. While I, myself, was also guilty of this, I still wanted to take the leap as I felt that it was a great learning opportunity. There were several approaches that I considered, and there were more than a few failed attempts. I have certainly gained a lot of knowledge from these failures, and I hope that I’ll be able to help some people out by sharing what I have learned. I’ve still got a ways to go, but this journey continues to be both exciting and rewarding.

My first honyaki was a Kenji Togashi/Hirosugu Tosa B#2 240 that came with a spectacular mirror finish. The hamon was only faintly visible at certain angles, and I attempted to bring it out using the same fingerstone progression that I used for a lot of kasumi finishes. It worked well enough, but I was totally unhappy with the overall aesthetic. It gave a nice even haze over the softer metal, but I wanted a more vibrant hamon and the result just wasn’t what I was going for. So I brought the entire knife back to a mirror and decided to regroup. At present, I nearly have the Togashi where I want it, but I’ll post more about this knife in the next few days once it’s completed.

I was fortunate enough to pick up one of the new Mizuno Tanrenjo KS-profile W#2 honyakis, and I had all intentions of trying out a few things on it after using her for a few weeks. Here are pics of what she looked like new and after a few lengthy prep sessions at home.



My goal for this knife was to bring out the hamon while keeping the area above it polished. The first step was to remove all of the patina, which was easily accomplished with 6 micron diamond paste applied on a hard felt block. My previous mirror polished were done using the felt blocks that Mark sells, which worked extremely well, but my buddy (shout out to Andreu) was able to find some harder felt blocks (from Durofelt) that I wanted to try out for this project. Once I was done with the 6um, I went down to 3um, and this is what I got.


There were a few deep scratches that the 6um was not able to erase. My guess is that these were already there but were obscured by the original hazy finish. These scratches can easily be deleted by using a higher grit, but my goal here wasn’t perfection. This knife is a part of my regular rotation so I didn’t feel a need to get rid of every little scratch. Plus, i didn’t want to waste any time or elbow grease if this attempted ended up as a failure. You can notice that there are areas of the hamon that are extremely light, mainly at the tip, heel, and several spots under the kanji.

So now it was time for the scary part...etching. I have played around with vinegar and lemon juice so I wanted to see what results I could get from FeCl. I drove down to my local Radio Shack to pick up some PCB etchant, but I had no idea that they aren’t around anymore. Rather than ordering online and waiting for a day or two, I decided to rummage through the chemical cabinet at work because we use FeCl for a few stains that we run. The strongest solution we had was 10% FeCl so please keep that dilution factor in mind. You will have to adjust things if you use a higher concentration. I applied the FeCl to the hamon only using a Qtip. I allowed it to sit on the blade for about 15-20 seconds before washing it off with soap & water. I applied the FeCl 2-3 times before polishing it back with the 3um diamond paste. Here is a side-by-side pic of the first etch and polish:


You can see that just this single round of etching/polishing was able to bring out the hamon in a few of the areas that were lacking. After seeing how easy it was to clean up the etched hamon, I slowly increased the aggressiveness of my etch by either leaving the FeCl on longer or by doing more etches before polishing. Here is the 4th round of etching and polishing:


Now that’s what I was shooting for! The hamon is nearly a continuous line from the heel on up. I still went ahead and did two more rounds of etching/polishing before taking all the way up to 0.5um diamond paste.


Those pesky scratches are still there, and the mirror polish can still use some work, but I still believe that I have achieved my goal. The hamon is now more vibrant than before, and it’s confirmed that my approach on this project was sound. In the future, I may decide to go for perfection, but that won’t be anytime soon because I love using this knife.

Next up...the Togashi. I got quite a bit done on her over the weekend (with some wonderfully unexpected results) so I’ll update you guys on that in the next few days.

[yg420]

Looks great! Sometimes it takes a leap of faith to discover what you’re capable of