Tormek SG & leather wheel - razor sharp

[van]

Graces for information.
Then knowing the knife manufacturer is important to know the type of steel used. This is ok for a new knife or kept in good condition. But for knives that have been used for many years and worn it becomes difficult to evaluate

[wootz]

Graces for information.
Then knowing the knife manufacturer is important to know the type of steel used. This is ok for a new knife or kept in good condition. But for knives that have been used for many years and worn it becomes difficult to evaluate

When I cannot identify the knife steel I "type the burr" as explained in the latest edition of the Knife Deburring book and the video https://youtu.be/7BGOT3oJ51Y
This way I determine the best deburring/de-wiring angle.

Van, simply deburr the unknown blade at the edge angle, and check for wire edge. If no wire edge, the blade is finished with Chromox and can go to the customer. If you see signs of the wire edge, give the blade more honing at a higher angle, for unknown knife steel try at 2 degrees higher than the edge angle.

We call our deburring method "differential honing" because it is minimum 2-step: removing the bulk of the burr, followed by de-rooting the burr that removes the wire edge. In reality, we do more honing steps for every knife, even budget, and get a cleanly deburred lasting very sharp edge. The apex we get - we call it "de-wired" - withstands cutting load better, has better edge retention, as shown by trials in boning at a Sydney meat plant - Our 7-Carcasses Edge

[van]

As always very exhaustive. Thank you
Your book is very interesting and informative, I have some difficulty in understanding some terms in English. I'm trying to translate it all into Italian for easy reading, understanding and consultation.
Until now I have always finished knives on the leather wheel with Tormek paste.
I decided to take two other leather wheels for use with diamond / chromox paste. What advice for the choice?

[wootz]

As always very exhaustive. Thank you
Your book is very interesting and informative, I have some difficulty in understanding some terms in English. I'm trying to translate it all into Italian for easy reading, understanding and consultation.
Until now I have always finished knives on the leather wheel with Tormek paste.
I decided to take two other leather wheels for use with diamond / chromox paste. What advice for the choice?

If you can afford two extra Tormek leather wheels:
- for removing the wire edge rub 1-micron diamond paste on one wheel;
- for finishing cleanup, cover the 2nd wheel with Chromox and rub in 0.25-micron diamond paste.

However, you can do with only one extra Tormek leather wheel with 1-micron diamond paste for removing the wire edge;
while the finishing clean up can be done on a strop with Chromox and 0.25 micron diamonds: "positive burr" blades are stropped on a hanging strop, and "negative burr" on a firm strop.

[van]

Thanks Wootz,
maybe it's a question of Google translator, but diamond paste and Chromox are the same thing?

[wootz]

I meant pure Chromium Oxide. Can be used as is or mixed with 0.25 micron diamonds.
We use Chromox (green) by Thiers-Issard https://www.thiers-issard.fr/en/razors-accessories/79-506-chromox.html

As to the diamonds, I buy oil-based diamond paste from a Hong Kong factory https://www.thk.hk
They also sell through eBay - search for THK diamond paste.
There must be producers in Italy/Europe, just Hong Kong is closer to us.

[wootz]

As can be seen on SEM images done by Todd Simpson, the chromium oxide grains, and a commercial diamond spray labelled as 0.25-micron, are close in size, both ranging from 0.15 to 0.5 microns. Because of this range, because the manufacturers label the diamonds by average size, when we say that finishing cleanup is to be done with <= 0.5 micron diamonds, practically we buy diamond spray or paste labelled "0.25 micron".

Chromium Oxide


0.25-micron diamonds


It took us a lot of sharpness tests in trial and error to conclude that the 1-micron abrasive de-roots the burr best of all - we recommend 1-micron diamonds for preventing/removing the wire edge.
Having removed the burr root, we do finishing "cleanup" honing with <= 0.5 micron diamonds, as above.

[wootz]

Van, I see you like it certain, and this is how to deburr mainstream stainless steel knives:

So, you have ground bevels and apexed the edge, as you mentioned before at 15 degrees per side (dps); you can feel the burr by brushing the edge with your thumb.
Control the grinding angle with our Grinding Angle Setter software.

1) Deburr on the Tormek leather wheel with the Tormek honing compound at the exact edge angle (e.g. at 15 dps) - till you cannot see and feel the burr; control the honing angle with our software for Frontal Vertical Base.

2) Remove the burr root (wire edge) on the 2nd leather wheel with 1-micron diamonds at 2 degrees per side higher (e.g. at 17 dps) - give it 3 slow passes alternating sides; again, use our software for Frontal Vertical Base to control the angle. No pressure on the blade at this step, just the weight of the knife and the knife jig - the diamonds will cut off the wire edge at its root.

3) Clean up with 0.25 micron diamonds, or with Chromium Oxide (Chromox), or a mix of them. You can do it on a 3rd Tormek leather wheel, or on a hanging strop, leather (smooth side) or denim. Finishing is important to clean up the deburred areas on the edge from any weak metal left after the burr breakout to get an "ideal" apex.
If you'll be using the wheel, do just 1 pass each side at the exact edge angle (15 dps); if you'll be using a strop, do 4 gentle passes alternating sides.

Between the honing steps clean the blade with turpentine to prevent cross-contamination of the honing compound.

As a result, the knife will stay very sharp for long time. You only have to advise your customer to use an edge-friendly chopping board (no bamboo, no hard plastic etc).

[John_B]

Vadim, I have a couple of follow up questions. At the end of your last post you say to not use hard plastic or bamboo for a cutting board. Is the hard plastic you are referring to PE (polyethylene) or HDPE (high-density polyethylene plastic)? Boards made of these materials can be found in most restaurants and many home kitchens. They are preferred as you can use stronger disinfectants and they are dishwasher safe. I did not realize bamboo was not edge friendly.

If the PE or HDPE plastic is not edge friendly how would you finish a knife that would be used for cutting vegetables and meat in a commercial kitchen?

Second question; In your original post am I correct that the blade was done at 10 dps and then honed at 10 dps followed by honing at 11.5 dps all using Tormek standard products? This is essentially steps one and two in your post yesterday. Step 3 is a refinement on how Al sharpened the knife.

I appreciate the time you put into answering these questions and my customers appreciate it as well. I think most of them think their knives were sharp out of the box and when they cut their first tomato after I sharpen them they are amazed.

Thank you

[Al]

Yes that's correct 1st honing was at 10 dps. 1 pass each side then repeat 1 more pass each side. The Bess at this stage from memory was around 180.then did 1 more pass each side at 11.5 dps and the Bess was 65. This result was all due to the patience of Wootz answering all my questions

[wootz]

Yes that's correct 1st honing was at 10 dps. 1 pass each side then repeat 1 more pass each side. The Bess at this stage from memory was around 180.then did 1 more pass each side at 11.5 dps and the Bess was 65. This result was all due to the patience of Wootz answering all my questions

Al's example is an illustration of the wire edge removal, and getting a clean robust apex, using the Tormek honing paste.

By using 1-micron diamonds for wire edge removal, we get even better sharpness, <= 50 BESS, and strong apex.

[wootz]

Vadim, I have a couple of follow up questions. At the end of your last post you say to not use hard plastic or bamboo for a cutting board. Is the hard plastic you are referring to PE (polyethylene) or HDPE (high-density polyethylene plastic)? Boards made of these materials can be found in most restaurants and many home kitchens. They are preferred as you can use stronger disinfectants and they are dishwasher safe. I did not realize bamboo was not edge friendly.

If the PE or HDPE plastic is not edge friendly how would you finish a knife that would be used for cutting vegetables and meat in a commercial kitchen?

...

The only truly edge-friendly plastic board is polyvinyl acetate Yoshihiro Hi-Soft cutting board.
May I refer you to this older thread? - https://forum.tormek.com/index.php?topic=3452

When I start with a new commercial kitchen customer, I give his chopping board 20 slices, checking BEFORE and AFTER knife sharpness on the tester. True that several times I met plastic boards out there that do not roll the edge and are not those expensive Yoshihiro, but unfortunately those boards were unbranded.
In the meat plants operators cut on the conveyor belt, and this belt is the main cause of the edge rolling; similarly the plastic chopping boards in commercial kitchens.
When we see that, we have to sharpen the edge at 14-15 degrees to better withstand the chopping board they use.

[John_B]

This is one of my go-to threads for a discussion on how to use Tormek products (mostly) to obtain a razor sharp edge. Since the last post Wootz has done some excellent research and testing using various cutting boards. The results are surprising. To complete this thread I am adding a link to his work on this subject.

http://knifegrinders.com.au/SET/Chopping_Boards.pdf

Discussion of this subject is also contained in this thread:

https://forum.tormek.com/index.php?topic=3955.0

[Nik3]

Hello. First Time poster.
IF i have used the black marker method to get the same angle for The knife on the sharpening Stone, how can i change the lenght of the legs of the USB so that i can Quickly change from Stone to leather wheel?

Best regards
Nik3

[Jan]

Hello Nik and welcome to the forum! 

You are asking a good question! As far as I know there is not an easy and quick method to accomplish your task. Probably the easiest way is to use the marker method again, this time for the leather honing wheel.

When you know your bevel angle and also wheel diameter and edge protrusion you can calculate the distance between the wheel surface and the USB.

Sometimes I use the so called double-ended kenjig. Principle of this method is described in reply#8 of the following thread https://forum.tormek.com/index.php?topic=3320.msg19878#msg19878

Jan