Category Archives: Dialogue

Knife conversation part 1 — Sharpening !!

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Nemo: when you buy a knife you will be sooner or later, depending of many factors, confronted to a dull edge. Getting away from the factory edge is like leaving your parent’s home: it’s uncharted territory for most of us. So should you waith for the knife to be dull or immediatly hit the stones to make it yours and why ?

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JD: When I get a new knife I check the edge to see what condition it is in. I pinch it between my fingers to see how thick it how thick the blade is just behind the edge. And just look at the edge see if the edge bevel is even. Some times you can see unevenness close to the ricasso. That will take some extra attention and work on the hone to get right. I use light to see if it reflects of the edge, if it does there is a dull spot. Then I check for a burr with my thump nail.
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If there is a burr I take a hone, usually the diamond side of the Fallkniven DC4, and remove it. Now I take a receipt of shopping, they are usually thin and consistent, and try push cutting and slicing it. If it cuts the paper cleanly and easily it is good enough to start using. If not, then I will sharpen it first. Depending on edge thickness, edge angle, and steel and what I feel like (knives are a hobby for me!) I will pic a hone and start sharpening.

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Nemo: knowing sharpening is your hobby is a knife easy to get dull a dream for you ? Or do you prefer your sharp edge to remain sharp for a long time ?
Would you enjoy D2 more than Elmax ?

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JD: a knife is for cutting and it cut better when sharp. I prefer a sharp knife! 🙂 It needs to cut what I need to cut with ease otherwise it is back to the hone it goes! I also like a knife that when it looses sharpness is easy to get sharp again. So I have no need for high wear resistant steels. But if they are thin at the edge and I like the rest of the knife it would not hold me back either.
If they are both well heat treated and kept cool in production and sharpening there after, both D2 and Elmax would work fine form me. I do not think I could tell them apart in use or sharpening. I am not much of a steel junky, though I like reading about the science of how steel works in knives. (I highly recommend the following books: (in German) Roman Landes: Messerklingen und Stahl and (in English): John D. Verhoeven: Metallurgy of Steel for Bladesmiths!) For me blade geometry and sharpness make a relevant difference. I can tell a thick knife from a thin knife and a dull one from a sharp one far better than the edge retention one steel from another.

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The biggest differences in steel that I notice are, first, how they sharpen, how easy or hard it is to remove steel, and second, how stainless they are. The last bit mostly when cutting fruit.

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Nemo: Sharpening wise: what would be the main difference between hollow ground knives and flat grind ?

JD: If they are the same thickness behind the edge the hollow ground blade wil take less effort to make the blade even thinner behind the edge, and take less effort to keep the blade thin behind the edge. Hollow ground knives can be laid flat on a hone to make and keep them thin. I have done this with a few knives. One of them a Spyderco Salt1. Now it is almost a single bevel grind (‘scandi’) and much thinner behind the edge. This has made it cut a lot better.  

The same can be done with a knife with flat bevels, it just takes more work. When you use and sharpen a knife for a while the edge gets closer to the back of the blade and gets thicker. When it gets thicker it cut worse. To make it cut well again the area behind the edge needs to be thinned out. As a hollow ground knife has less steel behind the edge it takes less work to keep it thin behind the edge.

On flat ground you often need to remove the scratches after …

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Spyderco C10WDP Endura 4 HAP40/SUS410 Satin Plain Blade, Mahogany Pakkawood Handles KnifeCenter Exclusive — Wooden Wonder Perfection !

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We all know how knives get personnal items and how many times we touch them and use them. Synthetic material got their practical side but natural materials provide some spirit to a folder. It gives nobility, it gets some gentle patina over the years and it makes your personal knife much more personal and more precious. Pakkawood is synthetic but it gives than kind of feel, add a steel spacer and steel liners and you got a bank vault workhorse of the 4th generation !!
The legendary Endura and Delica has now provided as the exclusive batch at the Knifecenter and they are not only great Spyderco’s but also near perfection EDC.

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First thing to notice is: this is not your regular Endura. Like the Orange Sprint Run C10FPBORE, this C10WDP is offering one of the best blade ever made in Seki: HAP40 steel clad between SUS410. HAP40 is like CPM M4 an high speed tool steel created by particular metallurgy and made by Hitachi. In my book it means a strong edge who will not chipped even if ground thin.

Quoting Spyderco: “HAP40 is a semi stainless, powdered high speed steel (HSS) that takes and holds an edge better than any other steel available on our site. HAP40 is fine-grained enough to sharpen very well and rates 64-68 on the Rockwell Hardness Test (HRC)—even harder than the traditional carbon steels used for knives. We have specified a hardness of 65-66 HRC for our blades. Unlike other HSS steels, it can be relatively easily sharpened on normal waterstones, if not quite as easily as traditional carbon steels.

We think HAP40 holds the potential to become one of the best steels on the market for the production of high quality, high durability kitchen knives.”

Edited on the 8th of  October: Semi stainless ? With 4% of chrome ?
What I can witness is that my HAP40 does not want to develop a patina yet when CPM-M4  is staining easily.

Perharps HAP40 is not a Japanese CPM-M4 but something closer to acording to CPM® REX® 45(HS)CPM® REX® 45(HS):
CPM REX 45 is an 8% cobalt super high speed steel which has excellent hot hardness along with good wear resistance and toughness, making it suitable for difficult machining applications. Made by the Crucible Particle Metallurgy process, CPM REX 45 has good machinability and grindability characteristics.Typical ChemistryCarbon 1.30%Manganese 0.30% (0.70%)*Silicon 0.50%Chromium 4.05%Vanadium 3.05%Tungsten 6.25%Molybdenum 5.00%Cobalt 8.00%Sulfur 0.06% (0.22%)Typical ApplicationsBroaches Milling CuttersEnd Mills Extrusion PunchesForm Tools Shaper CuttersGear Hobs Taps* The addition of .20/.25 S in larger diameter rounds (e.g. 2-9/16″ and over) provides a uniform dispersion of small sulfides throughout the structure, resulting in machinability and grindability benefits with no deleterious effect on toughness.”

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It’s even better than my superblue Stretch in term of long last edge and certainly less prone to pit or stain. So, it’s much better.
So the fact that the blade is clad HAP40 is a good thing; you get toughness and flexibility where it counts  on the spine and rigidity where it counts on the cutting edge. (quoting Sickael a forumite)

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Talking about perfection in manufacturing: the blade is perfectly centered and there is zero vertical play !

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The steel spacer and skeletonized steel liners gives a very solid feel and a high quality feel. This is the same spacer as on the G10 Endura. It’s not butt heavy, the knife is well balanced. You can noticed how the adjustement between the liner and the spacer are perfectly done.

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Of course the factury edge was on the razor side of the scale. With such a special steel it could be thinned by some work on sand paper to de-shoulder it or kept this way.

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Even if the endura doesn’t have a choil, when closed the blade falls by inerty gently on the index. Making the closing safe and fast. Perfect !

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“The wood is Pakkawood which is a stabilized laminate of birch with stain, but it is the best material for knife handles. It never warps, absorbs water or changes in any way and it looks great. It also polishes up with a buffing wheel to a high gloss. They are totally made in Seki City and I love my Delica. ” Howard Korn – The Knifecenter of the Internet.
Nuff’s said. This is a labor of love. The wood is warm under the touch and provides enough traction for serious cutting job. This knife is a user, a beautiful and rare user. A classical design enhanced by the choice of materials.

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Compare to the Stretch and Millie the Endura is taking her place just in between. A little thicker than my Stretch and longer too.

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Compared to my Millie, the blade is thinner but provide almost the same working edge. The Endura has always been an impressive cutting machine confirmed by years of production and refinement.

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For a must shorter handle tha the Millie, you are pocketing a blade enough long to cut bagels in half or split a melon.

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But I have found that the jimping on the blade were a little too much aggressive and by rubbing against the pocket’s lips it could ruin your denim in a week.

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It was fixed by using some diamond file turning the 90° edge…

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into a smooth rounded one. It was done in 2 minutes. This is something I also made on my Millie, Paramillie… The hump’s jimping is always catching and wearing my pocket.

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Now I prefer Tip Down carry for Spyderdrops and it gives a reason to have this holl in the clip.

So here it is: the best Endura version with a great “Wow Factor”. Even sheeples love it. It’s not menacing, it’s all in elegance and choice in refinement. This is a stunning folder and a rare Endura giving you the chance to carry a Grandpa’ knife with the last technology.

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And now let’s start to use it. The kitchen is my battlefield as the knives are subject to their main purpose: cutting efficiently.

Let’s try this on code fish and tomatoes. The factory edge is “honest” but this steel begs for a thinner manifestation, better efficiency.

No stain and no risk for that hande, the wood is stabilized.

So let’s use some diamonds. De-shouldering the edge and creating an apex.
And then gently stropping on leather. The wine glass i not mandatory.
The day after I was sanding the scales !