I'm actually reluctant to post this because I have posted it so often before that it almost seems like I am shilling for diamond films. I am not. It's just that I have used a lot of different abrasives and I want others to have the knowledge without spending the money I did.

The Atoma 140 and similar stones are great on the EP. But they have a very harsh feedback. If used without lubricant you can experience chatter of the stone as it skips over the blade. This is controllable on a larger knife such as a gyuto, but the smaller size of the folder makes it somewhat worse. Also, the knife wants to move around on the blade table more than a gyuto, especially when using a coarse diamond stone. It works, but it is in no way elegant.

For the steels you listed with Vanadium content I believe you will find the stock EP stones to be less than ideal. I'm being politically correct here, in that they actually suck. The high grit stones are in fact decent finishers, but the low grit...

Normally I would recommend a 125u 3M diamond microfinishing film to reprofile the V steels. This offers an aggressive cut, but without the deep canyons, and leaves a nice surface. I can go from 125u to 1K Shapton with no problem. But, even though the feedback is smoother than a diamond plate, 125u is still a bit 'much' for a folder. Hence I would recommend using the 3M 60u diamond lapping film, Type P, with a Pressure Sensitive Adhesive (PSA) backing, on a glass blank. It is a bit expensive at ~$10 for a 3"x6" sheet, but you get 3 EP size strips out of that. Each strip should perform a heavy rebevel on at least 2 folders before it is spent. The feedback is sweet, perhaps superior to that of a Shapton of similar grit. You can use dry or wet, although I just use dry and keep my face away from any particulates.

From there you can proceed into a diamond progression of 30u/15u/... (And if your glass blanks are thickness matched there's no diddling with the angle adjustment.) Or use whatever, since the heavy lifting has been done. The argument exists that using diamonds throughout will ensure the hard carbides are also formed with the edge so they don't drop out of matrix as the surrounding steel is abraded away. (Chocolate chip cookie theory.) Another argument is that you want the carbides to stand proud. Similar arguments exist about coarse versus refined edge when using these steels (which, of course, is also dictated by usage). I'm not going to weigh in on those debates here.

If you want to play with high grit edges, the diamonds go all the way to 0.1u. From 6u on I have found that you can save money by using the non-PSA backed films, using just a smear of water between the film and the glass to hold the film in place.

I buy my films from Precision Surfaces International, since they are one of the few vendors that will sell 3M sheets in small amounts. Digi-Key also sells 3M sheets, but the ordering process is a bit more painful and the in-stock selection for small quantities isn't that great. Diamond products are on the last two pages of the linked pdf.

http://www.psidragon.com/customer/prsuh ... A_2013.pdf

I dislike linking to other vendors but that's the way it is right now. I would encourage CKtG to buy a wholesale lot of these and offer them on the website. I believe they would be a steady seller for those looking for an alternative to the Shapton Glass.

Cheers,

Rick

Statistics: Posted by Tall Dark and Swarfy — Fri Oct 09, 2015 5:43 pm

]]>

ken123 wrote:

I think we may have cleared out the bar and put everyone else asleep

I think we may have cleared out the bar and put everyone else asleep

Perish the thought!

I stepped away for a moment to get a hot pretzel and another pint.

Statistics: Posted by joefriday — Fri Oct 09, 2015 5:42 pm

]]>

1. Are you right handed? YES

2. What type of knife are you interested in (gyuto, nakiri etc..) GYUTO

3. What size knife are you looking for? 210MM

4. Do you prefer reactive carbon or stainless steel? STAINLESS OR STAINLESS CLAD FOR THIS ONE

5. Do you prefer a western handle or a Japanese handle? MUST BE WA, PREFER OCTAGONAL

6. How much did you want to spend? SUB $300

7. Do you know how to sharpen? YES

8. Are you a home cook or pro cook? THIS ONE IS FOR HOME

9. If you are a pro, are you doing a lot of prep or is this a line knife or something else?

10. What kind of cutting board are you using? END-GRAIN MAPLE

Generally, I like knives with excellent food seperation, minimal wedging, and a decent flat spot. I would like this knife to be low maintenance, so no fully reactive carbons (though I'm including the Itto-Ryu in the running as it is hardly reactive). I was originally going to make this one a Tanaka Ginsan since I really want to try the steel and love my Tanaka KU, but they have been discontinued. I like SLD but think I would like to stay away from R2. I also like my knives on the taller side. So, for a 210, I want to stay above 46mm.

Some knives I've been considering:

Teruyasu-Fujiwara 210

Itto-Ryu 210

Saji Ginsan 210

Wakui Kasumi 210 (before the price increase...)

What else should I be considering? What knives have you enjoyed in this application? A big thanks for any help with this...I've been toiling for quite some time on this one...

Statistics: Posted by cjmeik — Fri Oct 09, 2015 5:41 pm

]]>

I personally find the Kajiwara (KU especially) to be pretty thick at the edge. The Takagi Honyaki can be pretty thick at the edge as well - I haven't seen any from more recent batches to confirm they are ground the same as prior batches.

I'm a lefty as well and most double bevel knives from CKTG don't steer (those that I've tried). The Fujiwara FKH Carbon knives and a couple others are the exception - for me.

I think the Hinoura is an excellent suggestion. They're very well made knives. The Koishi is a monster, but quite thin at the edge. It demands respect and good technique.

Statistics: Posted by SteveG — Fri Oct 09, 2015 5:30 pm

]]>

I do however enjoy what Ken and everyone else here is doing in this thread, even if I'm not able to follow all of it. I'm not a great sharpener, and most people here are sooo far beyond me in both skill, knowledge and experience. However, what baffles me sometimes is the point you made very elegantly about tradition, new ideas and scepticism etc. Often I have seen the rationalisation(which in my book it isn't necessarily) that this or that person has been doing this for 20 years so it must be right. Again, I have never questioned anyone's experience or know-how, but that doesn't meen their explanations for how or why something works/doesn't work hold true. It's just the diametrical opposite of science.

I will say I find the CKTG forum very open, respectful and accepting to different viewpoints, but other places online I've found a very different attitude..

I'm excited to see how this thread develops and how/if it will touch upon the question Ken raised about the anecdotal evidence regarding natural stones.

Statistics: Posted by halfdana — Fri Oct 09, 2015 4:49 pm

]]>

No arguments here.

My mother raised me like a veal. I remember whenever I would paint a rocket or airplane model as a child she would screech at me to put on my respirator. What 8 year old kid owns a respirator FFS? Shoulda made it into a bong.

So, of course, I went through a (rather extended) phase of living dangerously as many kids do. Eventually it all gelled and I learned how to live an exciting and fulfilling life through risk management. I start with a risk/benefit ratio. Is this activity even worth persuing, given known risks? I then modify behavior to eliminate risk where appropriate and mitigate the residual risks. Nothing Draconian, just simple and obvious stuff, like wearing a PFD when afloat and taking a cab home from the bar. Wearing Kevlar gloves when mirror polishing a yanagiba is applicable here.

The MSDS linked below is for the 3M abrasives that are embedded in a nickel matrix and either sold as a flexible sheet or affixed to an aluminum plate, similar to the Atoma.

http://multimedia.3m.com/mws/mediawebse ... D7SSSSSS--

I see the words 'irritant' and 'carcinogen'. I'm not going to hide in the closet under the stairs, but I figure a dab of Astroglide on the plate should do a good enough job of keeping any nasties in check.

Didn't mean for this to turn into a rant. Cheers!

Statistics: Posted by Tall Dark and Swarfy — Fri Oct 09, 2015 4:43 pm

]]>

That's interesting, I was actually just looking at the Hinoura. Looks like a nice blade. I'd the masakage is thin, then the only other one in considering is the kajiwara. I just think the takagi is a better knife in general. Only concern is the bevel.

Thanks

Paul

Statistics: Posted by PaulP99 — Fri Oct 09, 2015 4:42 pm

]]>

x squared + 0 squared = z squared

x squared = z squared

x = z

this would be the situation of a scratch of zero depth ie a theoretical smooth plane.

---

Ken

---

Ken

Statistics: Posted by ken123 — Fri Oct 09, 2015 4:27 pm

]]>

studio398 wrote:

Peter and Jason.

have either one of you decided yet on a natural stone? curious to find out what you both choose and what you think after you have a chance to try them. what about the yaginoshima asagi?

pat

Peter and Jason.

have either one of you decided yet on a natural stone? curious to find out what you both choose and what you think after you have a chance to try them. what about the yaginoshima asagi?

pat

That's one that is my list but I think I will be getting the Tsushima Nagura first. I learned long ago that buying too fine of a stone first is always a bad choice.

I have an old natural Aoto by it's a bit too coarse to jump to an 8k+ natural.

On a side note, I did place my order for the SG16k and Cerax 6k today.

Statistics: Posted by Jason B. — Fri Oct 09, 2015 4:22 pm

]]>

Yes Pythagoras requires a right angled triangle or at best degenerating a triangle into two right angled triangles.

An isosceles triangle does have two sides of equal length.

The sum of the included angles of a triangle is 180 degrees.

You can in fact have a right angled triangle that is ALSO an isosceles triangle. In this instance the right angle is 90 degrees and the remaining two angles must sum to 90 degrees and also be equal. Therefore the triangle has angles of 90, 45 and 45.

The equation still holds. x squared plus y squared equals z squared, but in this instance x=y so it simplifies to 2*(x squared) = z squared.

So if we look at a triangle set on a Cartesian coordinate system we can have the x side running along the x axis (length) and the y side running along the y axis . Here the right angle is made of the intersection of the two axes. The triangle can be in the first quadrant (both positive numbers, with the right angle on the left side of the triangle or in the quadrant to the left of that (y positive but x negative) where the right angle is on the right side of the triangle. These two triangles are mirror images of each other.

So when we look at a v shaped groove, we can look at the left side of the v as consisting of one right triangle of length x and depth y with the the hypotenuse being the left side of the groove. We do this again for the right side of the groove. Now we add both of these two hypotenuses together to get the total length of the groove.

I think you must have been thinking that I was trying to do the pythagorean theorem on the isoscles triangle that was the groove as a single triangle. You could play with this a bit to see that the inside of the groove can be considered as an isoscles triangle composed of two right triangles pointing in opposite directions and compute it that way, but those triangles are equivalent to the two triangles outside of the v groove.

Hope this helps. Once this point is clarified, give it another read and let's chat some more.

---

Ken

Statistics: Posted by ken123 — Fri Oct 09, 2015 4:20 pm

]]>