Jointing technique by Harrelson Stanley?

[brianleepy]

Hi

I stumbled upon a sharpening video by Harrelson Stanley on a Takamura and saw him using a technique called "jointing".

Basically after sharpening a knife he takes it and lightly grinds the knife perpendicular to the stone along the cutting edge. After that he hones the edge again a few times.

Here is a video of him explaining what jointing is. The starts to "joint" the knife at around 30:00. [video=youtube;5BV_IdXQ18Q]https://www.youtube.com/watch?v=5BV_IdXQ18Q[/video]

This seems counter intuitive to me. Also a micro bevel (thanks jon for the micro bevel video) seems to achieve the same thing but a lot less harsh. Any thoughts on pros/cons on jointing??

Thank you

 

[Framingchisel]

I follow this procedure in most cases, but tend to use diamond plates for the re profiling ie., jointing, and then Jon's 1k and 6k diamond stones with a final re-jointing and edge refinement on an 8k+ stone. Micro bevels may serve the same purpose as the last jointing and it will depend on the specific knife to get the best edge life. I the check on a plain strop to confirm that the wire edge is gone.
Jointing is the first step in sharpening handsaws as well.

 

[ThEoRy]

Just pull through cork or felt then strop.

 

[XooMG]

Works fine. For a kitchen knife, a bit of a ragged edge from standard "stripping" burr removal should be acceptable, but a jointing technique works pretty well on razors.

 

[James]

I might have to try this out with my new R2 knife; have had some weak edge problems with it

 

[XooMG]

I might have to try this out with my new R2 knife; have had some weak edge problems with it

Takamura? I have experienced and read about the same issue. Seems whatever they do to sharpen before sale is a bit harsh and the edge comes out a bit weak. I agree that a lower grit jointing ought to get you to some better steel quickly.

 

[James]

Not Takamura, but a rakuten find - http://global.rakuten.com/en/store/honmamon-r/item/4582243651752/

 

[Adrian]

Really interesting. I was shown how to do this in Japan (with many dire warnings about being accurate and gentle) but have never had it explained.

I have never seen a 30,000 grit stone either! I understood that Japanese measured gradings stop at around 10-12,000.

 

[Mr.Wizard]

I have never seen a 30,000 grit stone either! I understood that Japanese measured gradings stop at around 10-12,000.

The highest official JIS standard is 8000 grit, corresponding to a median particle size in the interval [0.9, 1.5] microns as graded by the electrical resistance method. The Shapton 30K stone is stated as 0.5 microns without further specification.

You may be interested in this project of mine: http://www.kitchenknifeforums.com/s...-in-Micron-Scale-Grand-Logarithmic-Grit-Chart

 

[panda]

Counterproductive.

 

[wphill]

I like this video. Thanks. I've re-prfolied a nakiri..and it needs some more tweaking so this was food for thought on technique.
In the midst of this project i admit to being a little nakiri crazed. The nakiri in the video does not seem typical. It's almost
dead flat except for that slight rise in the center...hardly a belly. When I look at the entire blade, I don't think
of it as a square dead flat profile. Instead, I think of it as ruler flat edge on a slope. For my own motion of a push cut/chop
when mincing mounds of vegetables I wonder whether I would prefer this long flat profile..I might~ OR the more common one
where the only dead flat space is just ahead of the heel..where it's not more than one third of the total profile. From there
the edge rises with a sweep upward. Dead flat is almost entirely confined to the back of the edge.

Anyone know brands that are more like the one in the video? I sure would like to try one.

 

[strumke]

Not Takamura, but a rakuten find - http://global.rakuten.com/en/store/honmamon-r/item/4582243651752/

That looks very similar to the Tanaka R2, except for the handle

(offtopic), but does anyone know if these are rebranded?
The Tanaka was a lot more expensive than this Heiss.

http://www.chuboknives.com/products/tanaka-sg2-gyutou-240mm-9-4

 

[James]

Could be. Someone was going to ask, but there wasn't any follow up on my thread. Besides the handle and my sharpening issues, it's a great knife.

Back OT - I think I remember a post from Mari that described this sharpening technique before. Someone from Masamoto, Misono or Suisin did it this way. I'll have a look through Korin's subforum and see if I can find it.

 

[zitangy]

Back OT - I think I remember a post from Mari that described this sharpening technique before. Someone from Masamoto, Misono or Suisin did it this way. I'll have a look through Korin's subforum and see if I can find it.

You are right.. she mentioned about " crushing the edge".

I figured that the main purpose is to break the wire edge quickily. Once it is broken off.. I suppose the edge is slightly rounded and you finish off with a few light regular strokes to get the Apex and hopefully do not overshoot and get another burr.

Controlling the pressure is critical as you are addressing less than 0.1 mm steel thickess ( at the edge). I normally use just the weight of knife and sometimes lighter . BUT if it is to remove nicks and chips or reprofiling.. whatever is required.

rgds

d

 

[Adrian]

Last year we spent most of an afternoon at Masamoto's in the street outside Tsukiji fish market in Tokyo, where after the shop closed at around lunch time we spent about 3 hours being shown how to sharpen a batch of knives but an incredibly nice young Japanese man who works there (we were also buying some knives for friends and colleagues in Germany and the UK). They used a very similar technique although I could see that they were taking the wire off, I also got it into my head that they were levelling the blade edge. They (the two young men there) spoke minimal english and we speak even more minimal Japanese so most communication was by showing and gestures (hence I may well have misunderstood some things.

One of the techniques they used on new knives off the shelf was to sharpen, then in effect knick the edge down and sharpen again, then repeat the cycle. My understanding was that this was to finish up with a robust and durable edge, as opposed to just a sharp edge. I am pretty sure we took some video of this so I will have to have a look through. This was on both white and blue carbons. Before any knife was considered satisfactorily sharp it was shown to an older man upstairs who approved it.

Adrian