I even didn't think about this project as a post on my blog, but after a struggle with it, I have decided to make a post about it. Today's subject is a 300mm Ittinomon Sujihiki in stainless clad. This is one of three knives that will be sent to me by the customer from Norway. At the beginning, I didn't recognize him, but later I found out that I met this guy in Denmark on one of JNS gatherings:D
This knife is an example why I don't like sharpening systems like Apex Pro on kitchen knives. They might be alright for EDC or bushcraft knives, but Japanese knives with various geometries need something more than just set angle. As you can see in the pictures below, this knife is very fat above the cutting edge and also exposed part of the core has vanished. This is due to extensive sharpening with the same angle.
Look how fat it is...
I wanted to save myself some time and I have started quickly from removing some metal on my belt grinder.
I am not good at freehand grinding, but it wasn't that bad.
And here is the grind after 15 minutes on the grinder.
I have scratched flat part of the blade near the tip and thus had to refinish the whole blade.
My next step was to correct the grind on the stones and finish thinning that blade.
While I was trying to do my best to get straight line, I have noticed a strange thing. Whatever I tried to do I couldn't get shinogi line straight just before the middle of the knife. Sometime later I have figured out that the blade is thicker in the middle than it is near heel. I could flatten the thicker place above shinogi to lower the line, but that would be out of the scope of my spa service and it would be a lot of work.
Two pictures below are showing that this waviness is equal on both sides and that was exactly what I could feel under my fingers. There is a good way of checking the thickness of the blade. Of course, it won't be an accurate measurement, but if you will do it with every blade then your muscles will remember it and you will be able to tell if the blade is thick or not. To do that keep blade in one hand and pinch the spine between your thumb and middle finger of the other hand. Then slide your fingers from the spine to the edge. This is why I knew that blade is thicker in the middle. You don't have to measure it with the callipers.
It's getting better. I was trying to follow original grind of that blade. It was little bit flatter on the left side and more convexed on the right side (opposite than on the picture below). That geometry makes sense because the left side is flatter to slide more easily through food and the right side has more convexity to separate food better.
Next pictures show some progress after different stones. I was very surprised when I have used my Bester 500 stone. Usually, I don't like it because it clogs very quickly and the feedback is awful on stainless steel. However, something pushed me to take it out of my drawer with the stones after two years of not using it and man... That stone is a beast when used with Ittinomon. I have two JNS 300 - Actual one and prototype of the size of JNS800 (soaker as well). I had one more JNS 300 before (the very first one), the muddy one and none out of these three stones were near as fast as Bester 500. I totally loved that harsh feedback. You could see steel particles on the stones instead of mud. Very nice feeling. Bester 500 is also harder than JNS 300s and thus made it possible to make a nice straight shinogi line, except for that place with broken grind.
If you really try and go slow you can make a shinogi line freehand on the stones. Compare picture below to the pictures from the beginning of the post.
To refinish everything I decided to use polishing mops with some compounds.
Here is the result of hand thinning and power buffing. To be honest I could live with that result, however, the wave in shinogi line was very annoying.
There was no more time to play with it because I have promised my customer that I will send it back and take into consideration, that I already had this knife for two weeks I had no time to lose. The last part obviously was to sharpen the knife. That was Thursday and I have promised to send it back on Friday. I have sharpened that knife on Thursday evening and when I finished I have noticed some scratches on the side of the blade. These probably come from my magnetic rack. It couldn't have been worse. I didn't give up and 5 minutes after coming back from work on Friday I have settled my grinder in my corridor and started working on that blade again. I should do it straight away because in two hours I have managed to do more than in 2 weeks. First of all, I have repaired the grind and this blade is not thicker in the middle anymore. Everything is convexed now, so the blade is smooth, but if you look at the right angle you can still see original grind. Also, I have sanded the handle, sharpened ''D'' point on it and finished it with few layers of Danish oil with final touch of Rennessaince Wax.
So there you go, final pictures. I am still trying to figure out how to take nice photos in my dark kitchen. Some part of highlights are burned, but there is nothing I can do about it at the moment. Maybe I will get a nice soft box in the future and few lamps. I hope that my customer will like his brand new knife and that it was worth it to wait. I said brand new, because it looks like new from shop. Pictures and video below just don't give any justice to that blade.
Here you can see the grind at the right angle.