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We have a massive amount of Edge Pro products so we figured it would be good to have a whole section on how to use the machine and what to use on it.
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"Aggressive" edge on EP and tomatoes

Tue Jun 18, 2013 1:50 pm

I've been using the EP for some time now and I appear to be hitting a wall. I can get my knives (and they are good knives -- masamoto ks and konosuke hd) sharp enough to shave arm hair but I have a tough time getting them to do what I really want them to do -- glide through tomato skin without sawing. As I mentioned on another post, I typically go 220, 320, then 600, deburring on felt at each step, and finally strop on boron carbide or chromium oxide-loaded strops.

Today I pulled out the EP manual for the first time in a long time and noticed it suggested using only the 220 stone for an "aggressive" edge. It then occurred to me that I may be over-refining my edge and should stop a a lower grit so I end up with something toothier, which may get me closer to my tomato-cutting goal.

Any thoughts/reactions? As anyone tried sharpening without going higher than 220 and, if so, what results did you get?

Thanks in advance.

Re: "Aggressive" edge on EP and tomatoes

Tue Jun 18, 2013 2:53 pm

Dead right - over sharpening for the application does that - good shaver but shitty slicer - reverse the situation - you cannot put arm hair into the food.....

It will also stay "sharper" longer.

I stop at #500 Shapton GS...

:)

Re: "Aggressive" edge on EP and tomatoes

Tue Jun 18, 2013 3:05 pm

@MR: Huh, that's interesting -- I did a bit of research on the internets and most people claim that a highly polished edge lasts longer than a toothy one. You've had the opposite experience?

Re: "Aggressive" edge on EP and tomatoes

Tue Jun 18, 2013 4:45 pm

FWIW (assuming anyone but me cares about this), I directed the below question to Ben and got hte below response:
**************
Ben,
I've had the apex for a couple of years now, and have been frustrated by the fact that after a 220, 320, 600 progression, followed by stropping on loaded leather or balsa, my Japanese knives get sharp enough to shave arm hair but won't cut through a tomato skin without a sawing motion. After doing some research, I realized that I'm probably over-refining for this purpose and need to stick to a lower grit stone. I pulled out the EP manual yesterday for the first time in a while and noticed that you suggested using the 220 stone only for a more "agressive" edge. By agressive, are you basically saying the same thing as what many call "toothy"? Any suggestions on the best grit to stop at for cutting tomatoes and bell peppers?

******
Daniel,
It is the leather strop and balsa that are taking the high edge off of your knife. Just finish with the 600 and remove the burr. Now try and cut a tomato. It should work perfect. However, I am really surprised that the edge will shave hair, that is a bit of a mystery. If you want a polished edge, on your Japanese Knives, you need to progress to the 1000 stone and the 2000 and 3000 polish tapes. This edge will just fall through a tomato and last much longer then the 600 edge. However this edge does not work on regular kitchen knives, just stick to the 600 for those knives. The polish also works well on pocket and all sporting and hunting knives.

Strops do not cut straight off of the edge. You get some wrap over the edge which softens the edge. The polish tapes cut straight off of the edge and will give you a much sharper and stronger edge.

Ben

Re: "Aggressive" edge on EP and tomatoes

Tue Jun 18, 2013 6:18 pm

Read the link & Google course finish edge retention....

http://www.bladeforums.com/forums/showt ... -quot-rope

:)

Re: "Aggressive" edge on EP and tomatoes

Sun Jun 23, 2013 2:45 am

The problem is with your hugh jump from a 600 grit EP stone to a 1 micron compound on your strop. From 600 grit to 16000 grit is too big of a jump for the 1 micron compound to have maximum benefit. This is what Ben is referencing and what I and most people prefer as well. A coarse edge acts more like a serrated edge ripping through, whereas a refined edge push cuts through a tomato quite nicely.

I suspect that the lack of performance you are getting is from just rounding your edges off with your strop. Try some of the intermediate grits before stropping and you will be much more satisfied. Also use light pressure with your strops.

---
Ken

Re: "Aggressive" edge on EP and tomatoes

Sun Jun 23, 2013 4:44 am

dannynyc wrote:"I can get my knives (and they are good knives -- masamoto ks and konosuke hd) sharp enough to shave arm hair, but I have a tough time getting them to do what I really want them to do -- glide through tomato skin without sawing.
Any thoughts/reactions?"

My thoughts & reactions are, this without ever in memory stopping at 600, <1> I don't think I'd strop a 600 edge with a 16k or 30k strop. I don't see the point unless its just to deburr, but I've never stopped at 600 either. <2> Confusion. Your KS & HD are sharp enough to shave your arm @600, but have to saw through a tomato. I mean, when you say "shave your arm" - I would imagine a 600 edge would yank then cut your hair. Irrespective of that, as you know - hence your frustration, it should rip through a tomato effortlessly. <3> "I realized that I'm probably over-refining for this purpose" I can link to a score of videos of highly refined edges falling through tomato skin like the tomato wasn't even there. A couple nights ago I brought my KS through a 1200, 5k, 8k, 1u, 1/4u (that far bc I was bored in my hotel room) free hand progression that thinly sliced unsupported tomato horizontally as easily as it passed a HHT.

I have to recommend, closely in line with Ben & Ken, to eliminate the strop. I'd buy a 1200, finish your progression there, and if you must strop, strop on the 1200 lightly.

Re: "Aggressive" edge on EP and tomatoes

Sun Jun 23, 2013 1:42 pm

Thanks everyone, these tips are really helpful. I've bought a 1000 stone and 2K and 3K polishing tapes. I'm excited to give them all a try.

Re: "Aggressive" edge on EP and tomatoes

Sun Jun 23, 2013 7:54 pm

DANNY <> Please update here, as I'm sure we would all like to hear about your results. I would...

Good luck.

Re: "Aggressive" edge on EP and tomatoes

Fri Jul 26, 2013 3:10 am

Just as a point of clarification, let's make sure we are all talking about the same thing here. The EP grit rating system is different than the Japanese rating system, etc etc

This should help us all in talking about the same thing:

Image

Now you can cut a tomato with a serrated blade or a very toothy edge and this helps rip through the tomato skin, however a refined edge can push cut a tomato with ease. Personally I'd rather push cut than slice as there is less wasted motion.

---
Ken
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