Toothy edge with a polished bevel.

[casher50]

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Re:Highly polished bevel with a toothy microbevel.
« Reply #13 on: Today at 12:38:49 am »
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I am experimenting with putting a toothy microbevel (edge) on a bevel polished up on a SJ (4000) wheel. This should be the best of both worlds: a beautiful bevel with an edge that cuts tomato skins cleanly.

Do this by:
Step1: Polish the bevel to a high shine with a 4000 grit Japanese Water Wheel.
Step 2: Establish a microbevel: Make the edge toothy by sharpening just the edge of the polished bevel with a coarse stone like the original 220 grit Tormek wheel. This will likely require using the marker method and making one or two light passes on each side. Most likely little or no deburring will be needed.
Step 3: Test results.
Step 4: Repeat and refine as needed.

[John_B]

Study has shown that knives with micro serrations dull at. A faster rate than a sharp smooth knife edge. Of course if you are only cutting tomatoes the edge should last if you are not contacting the cutting board. Serrations can be very sharp but longevity of micro serrations is a concern.

[cbwx34]

I am experimenting with putting a toothy microbevel (edge) on a bevel polished up on a SJ (4000) wheel. This should be the best of both worlds: a beautiful bevel with an edge that cuts tomato skins cleanly.

Do this by:
Step1: Polish the bevel to a high shine with a 4000 grit Japanese Water Wheel.
Step 2: Establish a microbevel: Make the edge toothy by sharpening just the edge of the polished bevel with a coarse stone like the original 220 grit Tormek wheel. This will likely require using the marker method and making one or two light passes on each side. Most likely little or no deburring will be needed.
Step 3: Test results.
Step 4: Repeat and refine as needed.

Nothing wrong with your idea... I think the problem will be the 220 passes on the Tormek to establish the "toothy microbevel edge".  It takes very little to do this, and will be hard to control, and will be hard not to raise any burr, that you'll have to clean off.  Very light, and I doubt it would take more than a pass on each side.

You can usually establish it with a single swipe or two on a regular stone or even a rod of some sort.  I'll often finish an edge on a ceramic rod... it will give it a bit of "bite" without changing much, and can be maintained that way for quite a while.

[John_B]

CB I have been using ceramic rods for some time to extend time between trips to the Tormek. I have 2 rods; one has 1000 and 2000 grit and the second 2000 and 3000 grit. Finishing on the 3000 will restore a blade to a level where shaving is easy. I know the toothy edge debate has proponents on both sides. My experience is that a smooth sharp edge lasts longer than a toothy one in general use. Throughout our lives we are faced with things where common beliefs are not supported by science. Examples in cooking are that marinades get absorbed into meat, melting fat is absorbed by meat making it juicy, etc.  people believe what they believe and i have grown tired of trying to convince anyone of anything.

[jvh]

I am experimenting with putting a toothy microbevel (edge) on a bevel polished up on a SJ (4000) wheel. This should be the best of both worlds: a beautiful bevel with an edge that cuts tomato skins cleanly.

Do this by:
Step1: Polish the bevel to a high shine with a 4000 grit Japanese Water Wheel.
Step 2: Establish a microbevel: Make the edge toothy by sharpening just the edge of the polished bevel with a coarse stone like the original 220 grit Tormek wheel. This will likely require using the marker method and making one or two light passes on each side. Most likely little or no deburring will be needed.
Step 3: Test results.
Step 4: Repeat and refine as needed.

IMHO bad idea.
1. You get really fine toothy microbevel with SJ-250 (4000 grit Japanese Water Wheel).
2. If you use SG-250 after SJ-250 wheel, much bigger burr probably appears on the edge again.
3. Lifetime of the edge will be significantly worse after using SG wheel because it will be more susceptible to damage due chipping of small fragments from the edge (teeth and burr).

Here you can look how the edge looks after sharpenning on wheels with grit 220, 1000 and 4000.


jvh

[cbwx34]

CB I have been using ceramic rods for some time to extend time between trips to the Tormek. I have 2 rods; one has 1000 and 2000 grit and the second 2000 and 3000 grit. Finishing on the 3000 will restore a blade to a level where shaving is easy. I know the toothy edge debate has proponents on both sides. My experience is that a smooth sharp edge lasts longer than a toothy one in general use. Throughout our lives we are faced with things where common beliefs are not supported by science. Examples in cooking are that marinades get absorbed into meat, melting fat is absorbed by meat making it juicy, etc.  people believe what they believe and i have grown tired of trying to convince anyone of anything.

Ok.

Just to clarify, I was replying to the OP... your post came in while I was typing.  I was commenting on the process... not the "toothy vs. fine" debate.   

[casher50]

Personally, I like polished edges MUCH better that toothy ones, except when it comes to slicing tomatoes and other such things. I have somewhere around 150 to 200 knives and once they are sharp enough (cut paper cleanly, shave and BESS test under about 150) I then start using my SJ200 Japanese Water Wheel (I have a T4) on them to see what happens.

I have learned that the Japanese Water Wheel (JWW) can make a knife look beautiful and little or no effect on it level of sharpness. However, with a little practice and patience the JWW can make a knife significantly sharper that it would otherwise be. For instance, I have knives that BESSed at about 130-150, and after using the JWW they end up having BESS scores around 75-90, and no further deburring is needed after the JWW.

This is when the idea of toothy edges with polished bevels came to me. Why could a knife not have both? What would prevent someone for taking a knife with a beautiful polished bevel and put a toothy edge on it? I haven't yet figured out the best technique for creating the toothy edge, but I am sure it would not be difficult to do.

I don't know if there is any practical reason to do this. Also, it is possible that people have been doing this for thousands of years, and I, in my ignorance did not know it. What do you think?

[jvh]

This is when the idea of toothy edges with polished bevels came to me. Why could a knife not have both? What would prevent someone for taking a knife with a beautiful polished bevel and put a toothy edge on it? I haven't yet figured out the best technique for creating the toothy edge, but I am sure it would not be difficult to do.

I don't know if there is any practical reason to do this. Also, it is possible that people have been doing this for thousands of years, and I, in my ignorance did not know it. What do you think?

You can experiment as you wish. Maybe you can find the right ratio between sharpness and functionality. If you will be satisfied, then it's good result.

For me is toothy microbevel a problematic concept. I can't say it's sharp because it rips more than cuts. Maybe it can be appropriate for some application (tomatoes?) but a sharp knife with clean apex will do the same work and it's universal.

Just for the inspiration Tomato knives by Pavol Šandor.

jvh

[Ken S]

Casher50,

I applaud your desire to explore new techniques. That pioneering spirit is one of the things which makes this forum so valuable.

As a fellow pioneer, I believe I have shared some good ideas, perhaps the most notable being the kenjig. I have also shared my ample number of flops. Perhaps the most notable was my absolutely brilliant idea, which was before Wootz' VFB, of my horizontal front base. This allowed a horizontal base with the wheel moving into the blade. This would allow the Tormek to be used like a dry grinder. The concept was outstanding, with the one dide effect of flooding water everywhere. 

On the bright side, I later discovered that it does work well with CBN wheels used dry.

Do not be afraid to venture forth with your ideas.

Ken

[John_B]

CB, I have been using the 2 ceramic rods on my personal knives for maintenance for about 6 months. I have been very pleased with how well I can maintain an edge without having to return to the Tormek. I was always worried about metal removal but it seems minimal. I still use a smooth steel before each use.