# Thinning and initial sharpening my Teruyasu Fujiwara Denka



## bryantcw (Dec 22, 2019)

I just wanted to make this post showing how I did the initial sharpening on this knife. I’ve been hand sharpening for about 5 years, and only recently bought Japanese knives. This is my second full sharpening to include thinning. I hope someone else sees this and realizes they can do this work if they decide to, without an insane amount of skill, belt sanders, JNats, or expecting perfect results. Here was my process and the results. I made a few different decisions on this knife than the last time I did it, and next time I will apply lessons learned to the next.

Here is the knife as I received it. Very nice looking knife. The grind was good, just a little uneven in some spots, nothing major at all. The finish on the exposed Jigane was probably 220 grit or so, pretty rough. The lacquer finish was ok. I scrubbed the knife with a worn out green scrubby and the lacquer smoothed out a lot. The handle is rough as others have reported. Doesn’t bother me very much. I might smooth it out, but I’m not sure I care enough to bother with the effort. The finger notch means you really choke up on it in a pinch grip, it makes the knife feel 10mm smaller in your hand. The aesthetic pushes my buttons for sure.







Here I’m thinning a little bit, and evening up the grind. I’m using an extra course diamond plate for this, and checking my work with a sharpie.






This was probably after 3 passes. It wasn’t an insane amount of work as the grind was quite good, I was doing this to make the knife feel like it was mine and just to know it was even throughout. I genuinely don’t think this work needs to be done to this knife out of the box, but I enjoyed the process.






The next two pictures show my progress after about 3 hours, working on the extra course and course diamond stones, and then up to the 500 grit Shapton Glass. I decided to stop here and finish with sand paper. Getting every scratch out with stones is a massive time investment and I’m doing this for fun, not internet points.










Here’s the sandpaper working the finish after thinning. I just cut little strips, folded in thirds, and used my finger. I have done it stones only, once, and I can’t say I see the point, for me. Especially since one sharpening session is all it takes to scuff it up if any grit touches your polished work. I would like to try some finger stones for this work one day.






Back to the stones to put an edge on it. Shapton 500, 1000, 2000, and a strop loaded with green compound.






The finished result. I blew through a fair amount of the kurouchi when I used the sandpaper. It was a trade off between scratch removal and kurouchi preservation. I chose to err on the side of scratch removal. I’m sure it would have been more intact if I had done all of this on the stones, but again, I enjoy this process but 8+ hours of grinding is not my idea of a good time. The finish is by no means perfect, but it works. I will use this knife and really anything more would just get damaged in use. In fact I already scuffed it while I was putting the edge. This is up to 2k sandpaper, then back to 1k. Next time I want to clean up the finish I probably would stop at 800, I liked the matte satin look at that grit.









Here is the choil. The convex is apparent. The grind gets thinner at the tip. I think the overall geometry is very good.


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## Gjackson98 (Dec 22, 2019)

Thank you for sharing! Great job!


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## labor of love (Dec 22, 2019)

Good stuff. Thanks for sharing


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## slickmamba (Dec 22, 2019)

Did you get a choil shot Pre thinning. And height measurements Pre and post thinning as well?


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## Garner Harrison (Dec 22, 2019)

This thread makes me want to time travel to back before I started to try and thin the edge of my knife 3 hours ago to tell myself about the sharpie trick >.> 

And your knife by the way looks amazing!


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## bryantcw (Dec 23, 2019)

slickmamba said:


> Did you get a choil shot Pre thinning. And height measurements Pre and post thinning as well?



I did not, but the amount of steel I removed is probably only a few thousands of an inch. I doubt it would have been visible on camera.

My goal was to make the convex grind it came with more even and attractive, as well as bond with the knife. I also wanted the ‘shinogi’ to move up a little bit.


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## Barclid (Dec 23, 2019)

bryantcw said:


> I did not, but the amount of steel I removed is probably only a few thousands of an inch. I doubt it would have been visible on camera.
> 
> My goal was to make the convex grind it came with more even and attractive, as well as bond with the knife. I also wanted the ‘shigane’ to move up a little bit.


Shigane?


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## ma_sha1 (Dec 23, 2019)

How much a difference did it make regarding to cutting? I may have to thin my TF A bit, the left side middle is a bit thick but I am afraid of Messing up


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## _THS_ (Dec 23, 2019)

That's definetely a nicely thin and well done job


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## lemeneid (Dec 23, 2019)

Nice work! You've definitely shown good fundamentals with the thinning. Now time to get a Jnat and continue with those fancy kasumi finishes


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## bryantcw (Dec 23, 2019)

ma_sha1 said:


> How much a difference did it make regarding to cutting? I may have to thin my TF A bit, the left side middle is a bit thick but I am afraid of Messing up



No idea. I took it out of the box, and got to work with the initial sharpening. All I’ve done so far is dice an onion.

If you do this by hand and stop often to check your work, you will not screw it up.


Use a sharpie to find and work the high spots and low spots
Check that the shinogi line is roughly even on both sides
If using synthetic or natural stones, as opposed to diamond or sandpaper on a plate, you’re going to dish the stone a lot, stop and fix it before it gets really bad
Most important. Have a goal, what are you doing and why. What is the finish line. Otherwise you’ll go too far or not like the result because you don’t know why you did what you did.


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## KingShapton (Dec 23, 2019)

Really good job!


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## Henry (Dec 23, 2019)

Nice...I am going to re-read this post before I thin out my Denkas. The polish of some of the kurouchi looks a little strange at first but then starts to look really cool the second time around.


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## ma_sha1 (Dec 26, 2019)

Too much free time during Xmas, I went ahead to thin my TF Maboroshi as the middle left side of the blade was bothering me.

The first picture shows before, you can see the downward curve of shinogi line, this area was Thick, & it’s right where the most used blade section is. 

The second photo shows a few hours later, I was able to thin down the hump, & straighten the Shinogi line. I used cheap eBay/Amazon double sided stones (400/800, 1000/3000, & 3000/8000). I also tried King 1000/4000, but they were soft & muddy, I went back to the cheap combos as they produced cleaner outcome. The soft stainless steel clogs up the stones easily, I had to clean the surface often by rubbing two stones against each other. 

After the stones, I went through sand papers 600/1000/1500. I initially went to 2000 but backed down to 1500, as it looked too shiny compared to Factory finish. Even 1500 is higher than factory, you can see it in the 2nd picture, the front area was not thinned, it’s already thin with a factory concave grind, I try to match it so the whole bevel looks consistent. 

Also, I used the stone for flat grind thinning first & sand paper to focus on top half of the bevel to restore the flat/slight convex factory profile. The right side of blade has a pronounced convex grind & the shinogi line was perfectly straight, so it was left untouched.


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## SilverSwarfer (Dec 26, 2019)

bryantcw said:


> I was doing this to make the knife feel like it was mine



This. A concept I know but never articulated. Reading this made me realize this is one of the underlying reasons why I always like to fix “low spots” and even out the kireba where applicable. Well, this and it gets me set up for polishing, which is the main reason. 

Also, great post! (Most) Everyone has a different approach and I almost always improve perspective and skills when considering anything I can glean from others’ ideas and processes. 

Thank you for taking time to post this content.


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## bryantcw (Dec 26, 2019)

Just wanted to follow up. I prepared a meal tonight with this knife. Chicken galantine with roasted root vegetables and gravy. I also made a stock and reduced to demi glacé to have on hand. I deboned a chicken and chopped probably 3 lbs of vegetables.

The performance of the knife is outstanding. From tip to heel, and the feel in your hand, I’m very impressed. All said and done it has a very few small micro chips along the edge, but other than that the edge isn’t visible under light. Very good wear resistance, just a little chippy. Expected for a carbon steel this hard. 

Raw chicken and onions etc, here is the resultant patina.


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## J.C (Dec 27, 2019)

Seeing all this hype about folks thinning their TF has triggered my passions to thin my maboroshi today. Main reason because it wedged through dense veggies like cabbage and big fat carrots.
Full progression with stones 400 x 1k x 3k x 6k
Still can’t completely remove all the low spots but really happy with the result, now it ghosts through carrots without any problem.


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## Carl Kotte (Dec 27, 2019)

@J.C. The first picture is pre-thinning and the rest post-thinning right? At least to me, pics 1 and 2 look really different. At any rate, good job and nice 6k finish! [emoji1303]


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## J.C (Dec 27, 2019)

Carl Kotte said:


> @J.C. The first picture is pre-thinning and the rest post-thinning right? At least to me, pics 1 and 2 look really different. At any rate, good job and nice 6k finish! [emoji1303]



yes you are correct
1st pic: choil before thinning
2nd pic: choil after thinning
3rd: 1k stone
4th: 3k stone
5th: 6k stone


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## Carl Kotte (Dec 27, 2019)

J.C said:


> yes you are correct
> 1st pic: choil before thinning
> 2nd pic: choil after thinning
> 3rd: 1k stone
> ...



Nice, thanks! [emoji16] What 6k stone do you use? It seems like it did the trick.


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## J.C (Dec 27, 2019)

Carl Kotte said:


> What 6k stone do you use? It seems like it did the trick.



arashiyama 6k. It is a good stone at reasonable price


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## lemeneid (Dec 27, 2019)

J.C said:


> arashiyama 6k. It is a good stone at reasonable price


My fav synth, awesome mirror polish if you’re patient too


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## ma_sha1 (Dec 27, 2019)

My TF after thinning behind the edge remains Thick in the middle, so I decided to go for round 2, thinning the middle.

The middle is much harder as it does’t have an existing bevel as guide. I clamped down the knife & used the stone to ride the blade instead. This is my “cowboy style thinning” inspired by watching videos of the masters. Toyama, Shigefusa & Kato all had shown a similar knife down thinning but using a metal shaving device instead of a stone.

It worked remarkably well, I can see exactly what I am doing with each stroke, precisely thin down only the middle to create another bevel, then blend it with the previous bevel.

In the end, I thinned the middle significantly, & achieved true convex grind. I am pretty sure I’d have messed up if I stayed with either John’s two 2-step convex grind or Carter’s rocking convex grind, both are stone down free-hand style requires more skills. I think the cowboy style is much better for beginners, this is my first time ever trying to thin the middle.


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