What Did You Sharpen Today?

This is a Kizer Envoy. It has a 2 15/16" or 75 mm. flat ground S35VN blade. This titanium framelock is easy to carry, and easy to use. The edge had some hard miles on it, and a healthy rolled area.

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The edge had enough deformation that I started with about 6 to 10 strokes per side on a DMT coarse diamond bench stone. This 300/45 stone got everything straightened out easily. It was already starting to shave and cut thin paper, although it was more suited to rough tasks at this point. I took about 10 to 12 slices per side on a DMT fine (600/25) and the blade was shaving comfortably and cutting receipt paper reliably.

I gave it a light stropping with Jende 4 mu. diamond emulsion on Nanocloth. I would have reached for a more coarse strop if I wanted to start polishing, but I just wanted to knock off any burrs and clean up the apex so it probably doesn't matter much. The fine stone left a deep enough sctratch pattern that it would have taken a long time and at least two or three more stages to get a high polish. I am trying to find a streamlined one-stone-and-one-strop solution that will provide an angry, agressive, masculine edge that will sacrifice a little polish in exchange for a little more cutting horsepower. This quick-and-dirty approach left a frosty finish that cut like a beaver.

A 13 degree angle guide gave me about 16.5 degrees per side. I just learned that you have to compensate for the primary grind of the blade (7 degrees in this case) when using the angle guides, so I used an angle gauge to dial that in. The angle gauge didn't make the picture. I always use the felt tipped pen and the loupe. The stones were lubed with a little Krud Kutter and water. I didn't need the brush to clean the stones.

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Kitchen knives for me and some Buck knives for my brother on the Toohr #3. 1 was used, the other 2 were new. The 2 new ones were pretty different on factory edge. One was ~15° per side, the other varied from around 20° on one side to 25-30° on the other.
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2 different Kershaw Alaskans for my brother, again, one used and the other new that I lucked into finding for him on the Tsprof Blitz Pro
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A recently found family knife. Dug up from the back of a cabinet, an Olsen OK knife. It has been treated pretty rough in its life.
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It, along with 2 other Buck knives, some more kitchen knives, the Kershaws above, and 2 Havalon blades all for family members.
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It would be interesting to take your knife in our lab to do some analyses what's in there. Must be 'hard as a rock' and loaded with carbides. Even Maxamet is not that hard to reprofile. The only knives I know that are so hard to sharpen are Sandrin knives made out of Tungsten carbide.
I can sharpen this one to cut printer paper .But it is not even close in sharpness compared with edges on my steel knives .I have only 800 grit DMT stone .Any tips to get it more sharp ?
I make it from TC disc from cardboard cutting machine , 1.2mm thick and according to manufacturer data 84 HRC .
Thanks !

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I forget ........I have also this one which are used for sharpening that disks ...I tried with them too , same result ?

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Didn't get any pictures because I'm not sure why, but I finally had a chance to sharpen some kitchen knives at home.
I sharpened an Aogami Super Murata Bunka, an Aogami Super petty, and 3 Tojiro DP (VG10) knives : a Gyuto, a Santoku, and a Petty.

The Tojiro Gyuto had a 1mm chip on the edge, and the Tojiro petty had a slightly damaged tip.
I sharpened all of them to around 100 BESS using a 320 grit stone, then finished them off on a 1000 grit stone with a few deburring passes at 5000 grit, and all of them had final BESS scores of 85 or less when finished. Depending on the knife they are all sharpened to either 12 or 10 degrees per side.

Pretty standard stuff.
 
I make it from TC disc from cardboard cutting machine , 1.2mm thick and according to manufacturer data 84 HRC .
I have some limited experiences with industrial cutting tools made of carbide hardness (turning, milling, drilling,…) but that's it.

If I would have your knife I would first try to get as fine edge as possible with my diamond stones and then I would use my strops loaded with diamond pastes from 15 microns down to 0.5 microns.
Just for the sake of it I would suggest you to read ''Carbides in S110V'' article on ''scienceofsharp'' site. There are also high-res SEM images. S110V is not carbide hardness but you will see how carbides in this steel look like and what you can expect when sharpening carbides.
 
My Wenger EvoWood got some love today on my Leading Edge sharpening system at 15dps.

I needed to do some stone comparison research today for Gritomatic between various stone types - obviously using the Poltava CBN stones on this fairly basic steel would normally be a complete overkill but it was mainly for stone progression research. I had to test about 10 different medium grit stones (various manufacturers) before I decided to start fresh again and go through to the Poltava stone progression also.

I did not add all the photos of the other stones, that was just some earlier research today on using a fairly basic stainless steel. After I was done, just for the heck of it I wanted to polish up the edge all the way.

Progression:

Poltava CBN metallic stones 120 through to 15k.
Suehiro Gokumyo 10k, 15k & 20k.
Lastly - Stroppy Stuff diamond compound on kangaroo leather 4 to 0.25 micron.

The sharpener:

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Some Edge microscope pics:

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Hello,
From reading here on BF I get the impression that you have quite a bit of experience with the Poltova or Hapstone stones.
I have been researching and gathering whatever information I could read up on. Yet, due to my fairly low level of expertise, I still haven’t come to a full conclusion of which ones I should get..
I’m hoping it’s alright to take some of your valuable time and ask you some questions. Please note that I already own 950grit, 1700grit and 4K grit EP diamond matrix. So for now I will only get stones for up to the 950grit.

Which of these grit progressions would you recommend, when starting with 200/160um:

1) First option:
- 200/160um, metallic CBN
- 100/80um, metallic CBN
- 50/40um, combined bond CBN
- 28/20um, combined bond CBN

2) Second option:
- 200/160um, metallic CBN
- 125/100um, metallic CBN
- 63/50 combined bond CBN
- 40/28 combined bond CBN

The reason I’m thinking CBN vs Diamond, is that the metallic CBN stones cut metal quickly, yet just a little bit smoother. Or are the unkrainian metallic and combined bond diamond so similar that it doesn’t make much of a difference.
While own a bunch of “super steels”, I also have some Aogami super blue, blue1 and blue2 knives and I read somewhere that CBN would be a better option for those.

The metallic bonded stones need to be etched. So getting stones that aren’t attached to a blank would make more sense? Or is it pretty easy to etch them, even with permanently attached to a blank?

I couldn’t find much info on the combined bonds. I assume they need dressing or etching, too?

Have you tried the pastes that PDT makes? If so, how did you like them compared to their competitors?

I thank you very much in advance
Hauke
 
I was just looking those edge microscope photos '777 Edge' attached.
Is it just me or there really is some slight convexing at the end of the edge after stropping?
 
Hello,
From reading here on BF I get the impression that you have quite a bit of experience with the Poltova or Hapstone stones.
I have been researching and gathering whatever information I could read up on. Yet, due to my fairly low level of expertise, I still haven’t come to a full conclusion of which ones I should get..
I’m hoping it’s alright to take some of your valuable time and ask you some questions. Please note that I already own 950grit, 1700grit and 4K grit EP diamond matrix. So for now I will only get stones for up to the 950grit.

Which of these grit progressions would you recommend, when starting with 200/160um:

1) First option:
- 200/160um, metallic CBN
- 100/80um, metallic CBN
- 50/40um, combined bond CBN
- 28/20um, combined bond CBN

2) Second option:
- 200/160um, metallic CBN
- 125/100um, metallic CBN
- 63/50 combined bond CBN
- 40/28 combined bond CBN

The reason I’m thinking CBN vs Diamond, is that the metallic CBN stones cut metal quickly, yet just a little bit smoother. Or are the unkrainian metallic and combined bond diamond so similar that it doesn’t make much of a difference.
While own a bunch of “super steels”, I also have some Aogami super blue, blue1 and blue2 knives and I read somewhere that CBN would be a better option for those.

The metallic bonded stones need to be etched. So getting stones that aren’t attached to a blank would make more sense? Or is it pretty easy to etch them, even with permanently attached to a blank?

I couldn’t find much info on the combined bonds. I assume they need dressing or etching, too?

Have you tried the pastes that PDT makes? If so, how did you like them compared to their competitors?

I thank you very much in advance
Hauke

I would go 200/160 then straight to 50/40, followed by your Matrix progression. With diamond / CBN, you can easily make bigger jumps between grits than with silicon carbide or aluminum oxide.

In reality, there is not much difference when hand sharpening with CBN vs Diamonds. It only makes a difference in higher temperature grinding. Both work very well on modern high carbide steels.
 
I was just looking those edge microscope photos '777 Edge' attached.
Is it just me or there really is some slight convexing at the end of the edge after stropping?

Correct - when using a soft substrate like leather, it will very slightly convex the edge. If you want less convexing, then a harder substrate (like wood) would be better.
 
Correct - when using a soft substrate like leather, it will very slightly convex the edge. If you want less convexing, then a harder substrate (like wood) would be better.
Thanks for the answer.
I only use leather strops and I don't mind convexing at all.
As I understand for successfull burr removal with strop there must be at least minimal ''wrap-around''.
I would say lots of sharpeners does not know this fact because they have never seen high magnification SEM images of edge before and after stropping.
 
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This is a Kizer Deviant, a formidable M390 blade with black linen micarta and white G-10 handles. The factory edge worked well enough but I was in a hurry to grind it off and get the bevels a little below 20 degrees. Here are the tools I used.

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I used the angle gauge to measure the primary grind (7.5 degrees) and I used a 14 degree angle guide to approximate a 17.75 degree per side edge.

I started with a DMT fine bench stone (600 grit or 25 mu.). Since this turned out to be a minor reprofiling job (mostly on one side) I should have started a grit lower. The results would have been the same with less time and less wear on the fine stone. Diluted Krud Kutter, a 10-15X loupe, a stone holder to get the tools up to a comfortable level, a ratty old towel that didn't make the picture and some receipt paper.

This edge was starting to shave but the toothy edge was a little too dramatic on my soft, feminine-like skin. Wrong tool for that job, which is okay in this case! It did settle down a bit after about five strokes per side on a flat balsa strop loaded with 10 mu. diamond paste. The bevels retained the even but easily visible scratch pattern from the 25 mu. stone, but the agressive strop knocked off any burrs and hopefully helped remove any bad steel left over from the factory edge.

Now the edge is slicing the receipt paper as smoothly as a well-polished edge, but you can hear the edge "chewing" through the paper! I am working on a one-stone-one-strop solution that will produce a beaver-like cutting edge that will still perform emergency surgeries. (In skilled hands, of course!) This 600 grit diamond and 10 mu. diamond strop looks like a very respectable combination for a practical, toothy edge that can still show off a little!

Edit: I just got off the BESS machine, and the blade averaged 145, a decent result for a stripped-down, one-stone-one-strop schedule.
 
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