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Hi all,

A few years ago I posted a repair job of a Ran with no tip and it was very appreciated on the forum so I thought i'd post another job this time with a Zen.
Be aware!
There will be some non-Tormek machinery aswell 

Among the comments there are loads of questions and a high interest of knife sharpening, which is nice.

https://imgur.com/gallery/x9w7Rop

I would thing it will turn out to be a quite awkward knife if you try to convert it.
Single beveled knives are among the easiest to sharpen by hand with a wet stone.

If however the costumer persist I would measure the angle of the single bevel and apply it to the non-beveled side. Note that the knife will have to be used in a slightly tilted manner in order to cut at least a little bit straight.
This will severely mess up the knife.

I would dissuade the costumer about the conversion and rather go for a sell of the knife and to buy a double beveled knife instead.

Best of luck, stay sharp!

Best regards.

Quite recently I stumbled over this very good explanation of what I think was your first question.
The reason for the shape of the cutting edge:
https://www.kitchenknifeforums.com/threads/a-basic-explanation-of-asymmetry.33951/

So, by sharpen the knife in such way you will get a more long lasting edge.
But you have a Tormek so why not sharpen it symmetrical and straight? - It won't last as long, but it's a quicker method for resharpening and it will have superior cutting abilities.


I hope this cleared some and didn't make it messier in the lovely jungle of master sharpening.

Best regards
Magnus

Around the 6:30 mark in the video below they show a machine and the technique i'm trying to describe.
Fun fact; I've visited the Yaxell factory twice, their master sharpeners are really nice guys and incredibly good at their craft.

https://www.youtube.com/watch?v=nqKoAaMxy3U


About if the different angles actually have specific purpose or if it's all in the hands of the maker I would answer; both.
My guess is that you probably won't notice any difference other than convenience in maintaining the edge if you reshape the edge to a symmetrical one.
Unless a costumer specifies how they wish for it to be resharpened I almost always sharpen it symmetrical.
If it's a deba shaped knife then of course it's a whole different story when it comes to resharpening.

I would use the method described by RickKung and his grand daughter, the marker pen. Adjust the tooling till you hit the spot and then go.
Identify the angle, as long as it lands between 10-15 degrees i'ts fine otherwise I would adjust it to somewhere there around and regrind it to a V shape with mirrored edges. As long as you don't have to remove too much material I don't think you will notice much of the changed angles of the cutting edge.

About the cutting edge being ground more on one of the sides comes from the knife maker or their master sharpener.
Mostly, if not always, their dominant hand is the right one and therefore sharpened more on the right side. This helps you as a knife wielder in terms of tipping over the produce you are cutting, potatoes, cucumber and what not.
With this slightly shifted edge to the right often comes that the edge on the left side can be of some what higher degree, as in more blunt angle, so when you use the sharpie trick you might find that it differs.
This again comes from the right-handedness of the sharpening master and the kind of machine they use in the factory.
The machine used is often a similar one that the link points at.
https://goo.gl/images/jzxBSp


Best of luck!

As mentioned above, use as little pressure as possible. If you increase it the risk of the knife digging into the stone is quite severe.
Have you done some experimenting on fitting the jig in the second position and turn the T-7 around so the stone rotates in the opposite direction?

Some times when I resharpen knives that has been broken in two and big amounts of steel needs to go I rotate the machine so I can apply a greater pressure and lower the risk of kickback from the knife.

Very interesting posts, Magnus.

You have both a T4 and T2. Would you please post about how the polishing wheels differ?

Thanks.

Ken

The polishing wheel is the same on T4 as on T7. The wheel on T2 is like a eraser with tiny particles in the mixture. It makes a similar result, not as shiny but it's quicker. It also leaves quite a bit of dust but it's expected since it's used dry.

Magnus,

as far as I know Seki is a small town in the middle of Japan which is famous for its production of fine knives like Solingen in Germany. I am wondering why you mention Hanoi, which is the capital of Vietnam? 

Jan

Ha! Of course, I guess the ol' brain wasn't with me. Nagoya was the city i referred to.
This is Yaxells factory.
https://www.google.se/maps/@35.4862514,136.9110042,3a,75y,269.09h,84.06t/data=!3m6!1e1!3m4!1sECGTa6GzetjeoK_awiUHMQ!2e0!7i13312!8i6656!6m1!1e1

Recently I was sharpening a knife made of Japanese stainless steel VG-10. I have noticed that the magnetically attracted steel fillings were different from fillings obtained by sharpening milder steels.

The gathered fillings derived from the VG-10 steel had granular character compared with the fillings from milder steels which usually form a bulge above the magnet which resembles hedgehog spines. I was wondering if the powder metallurgy could be the reason for it. 

Jan

Now when you say it I've seen it too. Possibly the filings of VG-10 has a tendency to arrange tip to tip more then other softer steel. Can it be the lack of carbon perhaps?

By the way, if I'm not mistaken, this "Made in Japan" is only referring to the steel. There are knifes like this, made in China and costs about $40~50USD on ebay or Aliexpress. I have one and like it very much. They are light and holding the edge pretty nice. HRc should be about 60-62
http://www.aliexpress.com/wholesale?catId=0&initiative_id=AS_20160826140032&SearchText=xinzuo+8+chef
Although IKEA has nice knifes too and are very cheap. Got them too.

You are quite right. In many cases a Chinese manufacturer buys its steel from Japan. How ever there are big differences in the Japanese manufacturers as well. As a costumer you would have to do your research and find out the process your self.
VG-10 for example can differ quite a lot depending on how it's treated though the process from sheet to finished blade. This is why you can find items that looks the same on paper but in reality can be totally different tools.

In this case, Yaxell, the knife is made in Japan. Yaxell gets their raw steel sheets from Takefu and the factory is in Seki just north of Hanoi.
I've visited the factory and it was really interesting. There were a lot of interesting discussions with their sharpening staff and their sharpening master.
Their handy work is just amazing and their machines looks quite different.

Thanks Mangus.
I went back and looked at the pictures again, and it made me realize, are you using it on the Tormek stand?
I saw the other wheel on the side and my brain said that image showed one Tormek, over another.  So I was thinking I might just be seeing you use one machine on the top of that IKEA stand, while the other was on a lower shelf.  Then I thought the wheel was off.  Sometimes I look at things and my concept is preventing me from seeing what is actually there.

Yes, it is a Tormek stand.
The lower stone is hanging on a small stud on the side. I have another stone hanging on the opposite side of the stand.
I can provide some more pictures of my corner once it's a bit more organised because right now it's a bit of a mess 

Steve's idea of dropping the spine to meet the edge got me thinking. Do large kitchen knives really need to come to a point? Is the point ever used? And is it more a danger as a cause of accidental injury than anything else?

In my opinion a point is always useful. On a larger knife, sure the point is perhaps not used as much as in smaller or peeling knives. So, why not, I see your point (!).
But maybe it would be seen upon as a some what decimated knife if it's missing it's point?

The reason I discussed this edge line with the costumer is that the knife won't dig in to the cutting board as much with this radius right before the tip.
As you guys know whilst cutting smaller objects in large scale the front part of the knife rarely leave the surface of the cutting board. And the knife is slightly moving to and front and with a straighter edge it's easier for the point to stick into the cutting board and killing the flow of the cutting. Not good when working fast in say, a competition.

Thanks for all the kind words.
I was thinking of dropping the spine a bit but due to time I went for the edge, but it's a good idea stevebot. I've done it several times on Global knives that's lost their tips.

SharpenADullWit, yes I have a T-2 and also a T-4

I will do some more documenting further on as more knives pass through.

Hello ppl.

Today a costumer handed in his 36001 with no tip so i took it to my grinding station and had a go.
This time i took a bunch of images and created a album on Imgur.
Here it is, have fun 

I'll gladly answer any questions or so.

Best regards from Sweden.

http://imgur.com/a/Bnyb7

Dry, I don't think it's designed to run wet. Probably due to corrosion or such.