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Re: What is your take on high grit ( 8k, 10K ) edges?

Fri Jul 26, 2013 12:02 pm

I think that I have been neglecting this stropping piece, I should be taking advantage of my higher grit stones to strop the knives. (Been using newspaper lately)

Last night I watched one of Murray Carters videos and we all know how much of an emphasis he places on this honing/stropping on a higher grit stone, the 6K in his case.

After the video I tried it on 3 knives last night using a 1K and 6K stone and I could definitely feel a difference with the edge, an improvement.

I have a beautiful 13K Sigma Power Select II stone that sits unused, I am going to try that next as the final step and strop the edge with it. (16k is my highest grit stone).

Re: What is your take on high grit ( 8k, 10K ) edges?

Fri Jul 26, 2013 12:31 pm

Yes, well Ken, we do know you like your edges 500k plus. :)

Re: What is your take on high grit ( 8k, 10K ) edges?

Fri Jul 26, 2013 7:27 pm

branwell wrote:"Yes, Ken, we know you like your edges 500k plus." :)


Re: What is your take on high grit ( 8k, 10K ) edges?

Sat Jul 27, 2013 3:23 am

Depending on steel I will go up to at least 8 k for my taste and 10 k when I can and one the thicker Richmond addict ones which were cpm 154 I go to a 15 shapton pro. Straight razors I try to stop with a coticule it just depends in the steel and razor along with what my beard is doing that week. Some razors 30k plus. But in general knifes are 8k and some are 10 just depends on the steel. Imop this sounds stupid but I have been accused of being a dumb ass, the knife will tell you what it can take by the way it feels on the stone. Like I said jmop. Peace, jmbullman

{legend} jmop. Just my own opinion, which for the most part don't mean much. All I know is my knifes are screaming sharp.

Re: What is your take on high grit ( 8k, 10K ) edges?

Mon Jul 29, 2013 12:20 am

There's a widespread and fundamental misunderstanding about what happens when "sharpening" with a high grit stone.

If you aren't drawing a burr, deburring, and revealing a fresh metal edge you're polishing and not sharpening.

At some point -- typically less than 5K depending on stone and knife, you can't make the edge any sharper (i.e., narrower), but only slicker, by polishing out some of the scuff and smoothing off the tooth left by the previous stone. Past that point, if you're making the apex where the bevels meet narrower (which is what "sharper" is), you're more likely creating a fine "wire" than a true edge.

I'm not disagreeing with peoples' experience and trying to say that highly polished edges do tend to stick in boards more than edges with less polish -- just making the point that they aren't actually sharper.

Highly polished edges are good for a few things, not important one way or another for most things, and actually counter-productive for a few others. They're a waste of time on knives made from alloys without much "scratch hardness" (different but related to Rockwell "indentation hardness"; a waste of time on knives which see a lot of duty cutting fibrous foods; and waste of time on knives which get maintained with a steel.

Nevertheless, if you enjoy sharpening it's fun to see how far you can take a knife -- no matter if the exercise is worthwhile in strictly practical terms you gotta take fun where you find it.

If you do polish as fine or finer than 8K JIS, be very careful about not leaving a wire edge.

I never take my Forschners or Sabs past a Surgical Black Arkansas (~4K) anymore. Sometimes I polish my other knives with sexier alloys on an 8K stone, and sometimes take them further using charged stropping compound. If I want a combination of tooth and polish, I finish on a diamond charge.

As a side note, it's always fun for me to see where Ken Schwartz and I come to fundamental agreement and then veer off.


Re: What is your take on high grit ( 8k, 10K ) edges?

Mon Jul 29, 2013 11:28 am

A few days ago I repaired/sharpened a 9" Wusthof chef knife for a fella that put a little dimple in the edge near the heel of knife after an encounter with a bone. He emailed me and told me he didn't find the knife as sharp as he expected it to be and was a little unhappy with the results. In 2 years this was my first complaint so I invited him over on the weekend with his knife. I picked up some very ripe tomatoes for the visit and decided we would do some sharpening/experimenation. He came, nice young guy who dreams of being a Chef and brought a little cutting board, a tomato, lemon and his dull knife. I tested the knife on telephone book paper and it sliced it but I could tell it wasn't up to par, there was room for improvement. He told me when he got the knife back he honed it with a steel. I told him he wasn't leaving until he was holding the sharpest knife he has ever used so we went to work. This was cool for me because I had someone who could provide immediate feedback on an edge, yes just a Wusthof but in my world, Wusthof and Henckels are extremely common.

I started with the Latte 400 and within 2 minutes had burrs formed/removed and a sharp knife. Then I used the Ume 1k I got from Ken and sharpened it, then I stropped the knife on the same stone, 5 times on either side and returned it to him. The goal was for the knife to penetrate the skin of the tomato without adding any pressure, just the weight of the knife and I made sure he wasn't using any force. It worked very nicely, he took it the lemon and shaved a little of the flesh off in. He was satisfied with the knife, sharper than new and he was smiling and ready to go. So I asked if we could take it further, to the point where the knife was polished and would slide over the tomato. (I don't think that is called "running" I think running is when the knife is so sharp it falls through the tomato with out feedback at all.....I'm likely wrong)

I stropped the knife only from this point on, I was completely satisfied with the 1K edge but I wanted to try stropping it on higher grit stones so the 5K Nubatama was used first. 5 trailing strokes, a quick pass of the edge through some soft wood and then 2 more trailing strokes on either side. Tomato test passed and he said he could feel an improvement in the edge. The 6K Arashyima was next and again, no problem but I don't really think he or I could feel an improvement in a 1k jump.

So I went to a 13k Sigma Power Select II stone and low and behold that worked as well but I believe it is because of the quality of that particular stone, it polishes yes but leaves a little teeth. I jumped back down to 10K and that is when we first noticed the polished edge sliding a little over the tomato.

I finished the little project with the 5K Nubatama, gave him his money back for the first sharpening and he went away happy and I learned a few little things too.

Now I'm going to try it again with leading strokes on the 5k and no stropping at all on the next dull Wusthof or Henckels I get..probably tonight, that tomato I have isn't looking too good so it will be a good test.

Re: What is your take on high grit ( 8k, 10K ) edges?

Mon Jul 29, 2013 1:14 pm

I learned a similar way you did after an unhappy person who I sharpened for complained his knife wouldn't cut I was dumbfounded, I learned a while back to test every knife that left on a tomato a tomato won't lie so I had him come over resharpened his Wusthoff and quickly found the problem, he had an ancient FDick Dickeron steel which was so abused that parts of the steel were missing and had divots in the flat part of the steel and I asked if that is what he did when I sent it back the first time and the answer was yes. I took out my 20 power loupe and showers him the edges were literally getting ground down every time he used it. And after a brief argument he ask for his money back and usually I hesitate unless its my screw up but I didn't want problems so I gave it back sent it on and him on their marry way as he told me I had now idea what the hell I was doing but he did notice the 15 or so I had in line which I was now running behind on. Later on his sous chef called and ask would i please sharpen his shun and I said you head chef said I had no idea what I was doing and I was not falling for that trap any more which the comment came please he had bought a cheap belt sander with a 120 belt and screwed his up to where it was blue and back and beyond use so he borrowed his shun and hit it with the dickron which it make a horrible sound than be banged the edge on the stainless steel table. After 2 1/2 hrs of fixing the dings, chips, angle of edge the gentleman was beyond himself with joy and left a hell of a tip and I now receive his and the others except for the head chefs who now mails his off and usually take two to three weeks to get it back. I have discovered that educating your customer is the best medicine for happy people. Before i take on a new customer I explain what I am going to do, a basic info one the expense of the stones, and just basic common sense and why was my knife sharpening higher the the other guy in town with the belt sander who is now out of business due to the fact he had no idea how to use it he just saw me bringing knifes into a restaurant and decided he knew how to be a sharpener also. I came home from a doctors appt. and there was a box nicely taped with instructions along with the guys business card on the outside which had his business name and a slogan why pay a lot for knife sharpening I charge 5 dollars per knife any knife! Quit using the old fashioned stone guys and go with the belt. That was on the back. Upon opening the boxes there were several high dollar yangiba's , chefs, debas, and one usuba. I was able to fix a few but when both side of the yanagi was sharpened at the same angle on both sides the usuba missing a chunk in the middle where it looked like the knife caught the belt and hit the shield up top and a few chef knifes. The chefs knife I made usable notice I said not fixed the only way to fix the was make them into a utility knife buy grinding the bad metal and one I got lucky he ended up with a hybrid santoku. I called told him the bad news and he begged to fix them all because some were over 300 dollars. I actually had to call his customers and explain why they couldn't be fixed and give them the speech on proper sharpening with a belt or a stone, he didn't have the balls to pick up the knifes and deliver not to mention apologize for his mistakes. I gained my jobs off that and he has went back to retail clothing work at an outlet mall. Education is the key to everything just like here we all learn from each other and if we don't no ask. Peace jmbullman. And I took them up to about 8k and did the tomato test before they left. Most of them liked a little tooth in their knife. I aim to please

Re: What is your take on high grit ( 8k, 10K ) edges?

Mon Jul 29, 2013 4:06 pm

Well this is an interesting and often discussed topic.

I guess I should start off by saying that I like a task specific edge.

Let me give some examples. A local restaurant that I sharpen knives for I routinely had been doing 2-4k level edges, but his main concern was quick turnaround and I strongly suspected that his requirements were very low for an edge. Besides his knives came back horibly abused - chips, blunted tips, dull. Used on stainless countertops, scraping cast iron pans, etc. And most of his knives are cheap knives too. So I switched to using an 8-0 grit belt followed by a 220 belt. He never noticed a difference. Now I charge him a very low price and can get a stack of them back to him in no time at all.

My own knives - I use all kinds of edges and lately use a lot of natural stone edges of unspecified grits. And yes I do also use edges as high as 640k grit edges. Extra work - yes. Pleasurable to cut with - you bet! I have no problem with tomato cuts at that level of refinement. As a home cook, I can get away with a more extreme edge than someone doing high volume in a restaurant. I'm totally unapologetic about this. Some of my knives just get touchups on a Kangaroo strop with some 0.1 micron compound or higher - 160K+. My straight razors get 0.025 micron touchups routinely and I don't complain about my shaves :)

Now if I'm using a knife like a European chef's knife - the steel limits the practical amount of refinement, so BDL and I aren't too far off. And if you are touching up an edge with a steel, especially a ribbed one, then yes a refined edge is a waste of time since the steel is wiping it off on the first swipe.

I'm always amazed at the idea that using a steel to realign an edge is OK where you are continuing to use weakened steel for your edge, yet somehow it is assumed that a highly refined edge is a wire edge of some sort.

"If you aren't drawing a burr, deburring, and revealing a fresh metal edge you're polishing and not sharpening. "

Here BDL and I do part ways substantially. I often specifically DON'T draw a burr or make wire edge to deburr. I feel this method of sharpening is a deeply flawed but commonly stated concept. When you sharpen, the goal is to get the two sides of a knife to meet in a perfect union. Once the two sides have met, if you continue to sharpen, you generate an unnecessary burr. Then you break off this weakened metal which you have CREATED by going past this point of union. Now you have two sides that no longer meet, but instead have an exposed fracture plane of work hardened steel as your edge, with the high probability that you have additional fractures extending back into the very steel you are going to use as your edge. This yields a weaker edge than if you had not generated the weakened steel to begin with. And creating a wire edge on purpose to break the entire wire off is an even more excessive case of generating even more weakened steel. Instead I suggest generating the smallest possible burr - if you need to - at an 8k or higher grit level and not earlier. The idea of making burrs at each grit and breaking them off reminds me of Sisyphus, endless condemned to push a rock up a hill over and over.

http://1.bp.blogspot.com/-IdMARwCE-AM/U ... syphus.jpg

I'd also like to point out the confused use of the term stropping, which I've mentioned in the past. It is best to think of simply the grit level and the stone or piece of leather or other substrate that the grit is on. So for instance, stropping on a 4 micron CBN strop is often a good enough edge preceded by a 1k stone. And this is far coarser than a 30k stone, even though it is a 'strop'. Stones strops, belts, etc should be considered as a continuum, where you simply pick the grit level and abrasive type suitable for the edge you wish to produce. The distinction between sharpening and polishing is an equally false premise and should be obvious to anyone who has seen an edge under magnification.

While I do have additional points of disagreement with other points raised, I figured that just going over one sentence's worth of disagreement is enough for starters :)

"As a side note, it's always fun for me to see where Ken Schwartz and I come to fundamental agreement and then veer off. " +1 :)


Re: What is your take on high grit ( 8k, 10K ) edges?

Mon Jul 29, 2013 5:01 pm

Ken as usual I think your spot on and on my sabatier's older Wusthof, henckels , not the internationals a completely different beast all together I go up to my surgical black and usually translucent most say the translucent isn't ant better that the surgical black but I disagree you say tomato I say tomoto. The other nite I couldn't sleep so I figured be productive and sharpen my 3 that needed done and they were the Horomoto AS, the Kikiuchi TKC I think is the last three letters without looking it up but people know what I am talking about and the Tojiro Dp in VG10. This was just a touch up except for the Horomoto as I had dropped it edge first on the cutting board I didn't see anything wrong so out came the Boroscilate home and went from there but I still wasn't happy with the edge. The Tojiro I hit with a nubatama 6k than a Snow White 8k and finished with the 10k nubatama and it slices through tomatoes with no effort. The Kikiuchi started with a 4k shapton, 6k, nubatama, 8k Snow White than the 10 nubatama followed by a 15 k shaptons pro than stropped on kangaroo hide, and the exact same on the Horomoto AS, stropped on kangaroo Hyde and good to go. All three passed the Jmbullman tomato test as the are now cooking in a pot of spaghetti sauce. My straight razor is finished with a 30k shapton gs and I have no problems shaving that is the stainless razor and the carbon steel str8ight razor is finished with coticules and finished on horse Hyde. I see both sides of the coin and as to what each metal would take but some of these steels are coming in at almost 70 Rockwell and the new Wusthof Ikons are comeing off the line at 58-60 Rockwell. I believe every knife is different and every knife even the same brand and model might prefer different grits and different stones especially j-Nats which is another story in it self. I see both sides and I agree we should all stick with each others own personal style and sharpen till the cows come home. Peace to all, jmbullman
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