Author Topic: How to get razor-sharp knives on Tormek  (Read 4324 times)

Offline wootz

  • Sr. Member
  • ****
  • Posts: 467
    • View Profile
    • knifeGrinders.com.au
How to get razor-sharp knives on Tormek
« on: June 29, 2018, 11:38:12 pm »
Case study in the Australian Knife Magazine: http://knifegrinders.com.au/Home/issue4_article.pdf
Video-1: https://youtu.be/ZDPXqAK9Xr0
Video-2: https://youtu.be/UckPmizllk0
Video-3: https://youtu.be/3yg_bKczR1E

We call it a METHOD because it has nothing to do with individual sharpening talent.
Actually, everyone in our team is hopeless in freehand sharpening. Freehand sharpening is tranquillizing?! - we find hand sharpening painful, wasteful in time and $, and extremely frustrating.

Everyone should be able to get the same or better sharpness following the process.

« Last Edit: October 28, 2018, 11:05:00 pm by wootz »

Offline Grizz

  • Full Member
  • ***
  • Posts: 118
  • USAF (RET)
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #1 on: June 30, 2018, 01:04:05 am »
as you know, I have consistently achieved less than 100 bess using your process with the FVB and the app + using the app for the paper wheel. spot on.

Offline wootz

  • Sr. Member
  • ****
  • Posts: 467
    • View Profile
    • knifeGrinders.com.au
Re: How to get razor-sharp knives on Tormek
« Reply #2 on: June 30, 2018, 02:19:52 am »
I know Grizz, thank you. As a matter of fact, I am in correspondence with many amateur and professional sharpeners from Europe, USA, Asia, Russia and of course Australia who sharpen their knives under 100 BESS using our approach, and this allows us to call it a method.

Offline cbwx34

  • Hero Member
  • *****
  • Posts: 1234
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #3 on: June 30, 2018, 02:35:38 pm »
Case study in the Australian Knife Magazine: http://knifegrinders.com.au/Home/issue4_article.pdf
...

Some questions if I may...

In the article you write:
Quote
We have developed a method to sharpen knives sharper than a razor using power equipment, within time span that makes it viable for commercial sharpening.

How long does it take on average?

You also mention that you use a "Razor Edge Edge Tester" as part of the final testing.  I know what it tests for, but I'm just curious if you can get an indication of how an edge might score on the BESS, just from using the Edge Tester?  Just wonder if you notice any correlation there... either formally or informally.

Finally, you write that this is "sharpening a knife to presentation standard".  What (if anything) would you do different for the "average" steak knife (not necessarily a cheap one, but one that isn't sharpened to this standard)?

Good article overall... I think it's a good example of a specialized sharpening for a specialized purpose.

Offline Grizz

  • Full Member
  • ***
  • Posts: 118
  • USAF (RET)
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #4 on: June 30, 2018, 07:02:58 pm »
Case study in the Australian Knife Magazine: http://knifegrinders.com.au/Home/issue4_article.pdf
...

Some questions if I may...

In the article you write:
Quote
We have developed a method to sharpen knives sharper than a razor using power equipment, within time span that makes it viable for commercial sharpening.

How long does it take on average?

You also mention that you use a "Razor Edge Edge Tester" as part of the final testing.  I know what it tests for, but I'm just curious if you can get an indication of how an edge might score on the BESS, just from using the Edge Tester?  Just wonder if you notice any correlation there... either formally or informally.

Finally, you write that this is "sharpening a knife to presentation standard".  What (if anything) would you do different for the "average" steak knife (not necessarily a cheap one, but one that isn't sharpened to this standard)?

Good article overall... I think it's a good example of a specialized sharpening for a specialized purpose.
CB, it is hard to give an average, but I will try.
if the knife is in the 400-500 range, then it is about 5-7 minutes including setup to get in the150-200 BESS range or scale. general touch up, no nicks etc.
if the knife requires removing nicks, regrind bolster etc,  then the average time would be about 10-15 minutes to bring it to the 150-200 range.
for the edge tester, I usually do a before and after reading from the BESS and give the customer a copy as well.
one can usually guarantee 150-200 BESS readings. That is in the utility razor blade sharpness. most high end cutlery (new) is about 250-350 BESS, some even as low as 200.
hope this helps. 

Offline cbwx34

  • Hero Member
  • *****
  • Posts: 1234
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #5 on: July 01, 2018, 02:55:20 pm »
CB, it is hard to give an average, but I will try.
if the knife is in the 400-500 range, then it is about 5-7 minutes including setup to get in the150-200 BESS range or scale. general touch up, no nicks etc.
if the knife requires removing nicks, regrind bolster etc,  then the average time would be about 10-15 minutes to bring it to the 150-200 range.
for the edge tester, I usually do a before and after reading from the BESS and give the customer a copy as well.
one can usually guarantee 150-200 BESS readings. That is in the utility razor blade sharpness. most high end cutlery (new) is about 250-350 BESS, some even as low as 200.
hope this helps.

Helps, (but still would like input from the author of the "Case Study"). ;)

Offline Grizz

  • Full Member
  • ***
  • Posts: 118
  • USAF (RET)
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #6 on: July 02, 2018, 12:06:20 am »
here is another article posted by sharpco.
https://www.tormek.com/forum/index.php?topic=3663.new#new

Offline wootz

  • Sr. Member
  • ****
  • Posts: 467
    • View Profile
    • knifeGrinders.com.au
Re: How to get razor-sharp knives on Tormek
« Reply #7 on: July 03, 2018, 07:33:18 am »
Another knife in 52100 HRC 63 sharpened for the same knifemaker to 40 BESS at 17 degrees included - sharper than a razor, splits hair and cross push-cuts cigarette rolling paper. When the customer ordered this knife he specified the steel and edge angle of 17 degrees.

Edge was beveled edge-leading on Tormek with CBN wheels using our software, mirror-polished on Tormek SJ edge-trailing using FVB, and the edge apex refined/deburred on paper wheels with diamonds. Edge angle verified with the CATRA laser protractor to meet the commissioner specs.



The photo is unedited, taken in daylight - the mirror finish is so perfect that the blade blends with the reflection like a stealth.

Instagram: https://www.instagram.com/snakeandrabbitknives
Facebook: https://www.facebook.com/snakeandrabbit

« Last Edit: July 03, 2018, 12:44:53 pm by wootz »

Offline Grizz

  • Full Member
  • ***
  • Posts: 118
  • USAF (RET)
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #8 on: July 03, 2018, 02:57:02 pm »
absolutely amazing Wootz. Great job !

Offline Dutchman

  • Jr. Member
  • **
  • Posts: 52
  • Ton N.
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #9 on: July 03, 2018, 04:24:48 pm »
About edge angle in the aforementioned article posted by sharpco: https://knifesteelnerds.com/2018/06/18/maximizing-edge-retention/
quote:
You can see that the initial cut length with a smaller angle is considerably higher and that the difference holds basically to the end of the test. This finding is significant because some have speculated that lower angle edges start out sharper but a more obtuse edge lasts longer [2]. And with the high wear that occurs in the CATRA test it isn’t likely that the situation would reverse with even further cutting. The initial blunting rate is relatively rapid regardless of angle and it then begins to level out. The highest TCC measured was over 1000 mm with an angle of 20°, and this decreased all the way to under 100 mm with 56°.

That underpins what I quoted in my first document  (https://www.tormek.com/forum/index.php?topic=1849.0) from “the Society for  Culinary Arts & Letters”:
The Myth of Thick Edges
The theory is that thick edges (larger angles) last longer than thin edges, and the majority of the knife buying public wants the edge to last as long as possible. But it doesn’t work out that way in practice. Thinner edges actually outlast thicker edges almost all the time.
The thinner edge starts out performing better than the thicker edge. So even if it does degrade it has a lot of ground to lose before it falls to the performance level of the thick edge.
Thinner edges cut more easily, putting less stress on the edge. If a thin edge takes three slices to get through a big slab of raw meat, a thicker edge might take six or seven. Or three with a lot more force. The thicker edge is doing twice as much work, degrading twice as quickly.
Thinner edges are easier to control. Lateral stresses are a significant source of edge degradation. The more smoothly, accurately and easily you are able to cut, the less lateral stress you put on the edge.
Thin is good.


Offline Grizz

  • Full Member
  • ***
  • Posts: 118
  • USAF (RET)
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #10 on: July 03, 2018, 05:05:56 pm »
Ton, I totally agree with that ! imho that is a true statement !

Offline wootz

  • Sr. Member
  • ****
  • Posts: 467
    • View Profile
    • knifeGrinders.com.au
Re: How to get razor-sharp knives on Tormek
« Reply #11 on: July 04, 2018, 01:48:07 am »
The antique wootz swords in my collection that still have a battle-ready sharp edge show around 9-10 dps on a laser protractor.
Or take for example hardened felling axes – they are sharpened at 25° included and sharp enough to shave with.

What Larrin Thomas (knifesteelnerds.com) has proved for high-end wear-resistant steels, we've proved for mainstream knives http://knifegrinders.com.au/16SET.htm - see there Edge Stability in Butcher’s and Kitchen Knives as a Function of Edge Angle and Initial Sharpness

For the best performance the knife edge must have the lowest angle its steel can hold; give your edge the least possible angle not over-thinning the edge past the angle at which it deforms in cutting certain stuff you intend to cut.
As Larrin has said elsewhere, we'll keep repeating this till it sinks in.
.
« Last Edit: July 04, 2018, 02:35:17 am by wootz »

Offline wootz

  • Sr. Member
  • ****
  • Posts: 467
    • View Profile
    • knifeGrinders.com.au
Re: How to get razor-sharp knives on Tormek
« Reply #12 on: October 28, 2018, 09:00:56 pm »
Kent (Sweden):
"My first measurement with my long-awaited PT50A. I am very pleased and fully attribute the result to the methodology I've learned from you."



Video: https://www.youtube.com/watch?v=fqFWu1JUEJc

Youngbin (Korea):
"I get 50 BESS on Tormek with the FVB. The FVB is great. Thank you Vadim."



Video: https://youtu.be/sx74ltiu3TY

***
The question I've been asked many times, if any knife can be sharpened sharper than a razor.
This method works for steels prone to form "negative burr", and many of those in-between, as explained in our study http://knifegrinders.com.au/Manuals/Knife_Deburring.pdf
.
« Last Edit: October 29, 2018, 03:20:16 am by wootz »

Offline Fernando

  • Full Member
  • ***
  • Posts: 102
  • Clean Cut.
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #13 on: November 16, 2018, 05:07:57 pm »
Kent (Sweden):
"My first measurement with my long-awaited PT50A. I am very pleased and fully attribute the result to the methodology I've learned from you."



Video: https://www.youtube.com/watch?v=fqFWu1JUEJc

Youngbin (Korea):
"I get 50 BESS on Tormek with the FVB. The FVB is great. Thank you Vadim."



Video: https://youtu.be/sx74ltiu3TY

***
The question I've been asked many times, if any knife can be sharpened sharper than a razor.
This method works for steels prone to form "negative burr", and many of those in-between, as explained in our study http://knifegrinders.com.au/Manuals/Knife_Deburring.pdf
.

the subject is really interesting.
just one thing, the link to the pdf did not work for me, can you verify it?

Offline RickKrung

  • Hero Member
  • *****
  • Posts: 646
  • Maker
    • View Profile
Re: How to get razor-sharp knives on Tormek
« Reply #14 on: November 16, 2018, 05:56:58 pm »
the subject is really interesting.
just one thing, the link to the pdf did not work for me, can you verify it?

Fernando,

The link on Wootz's Knife Grinders site does work:
http://knifegrinders.com.au/Manuals/Knife_Deburring_book.pdf

Note that this URL includes "_book" at the end of the file name, whereas the one in the link above does not. 

I am hoping these are actually the same document.  Wootz will have to verify if different. 

Rick
« Last Edit: November 16, 2018, 06:04:36 pm by RickKrung »
If you want nice clean, fresh oats, you must pay a fair price. However, if you can be satisfied with oats that have already been through the horse, that comes at a lower price.