Auf Youtube sind da unterschiedliche Materialien zu finden, das geht von gepresstem Papier, über Karton (wie hier) bis zu einigen, die sich die Scheiben aus MDF machen...
Auf Youtube sind da unterschiedliche Materialien zu finden, das geht von gepresstem Papier, über Karton (wie hier) bis zu einigen, die sich die Scheiben aus MDF machen...
At this point in time i have no hands-on experience with MDF for this particular method of motorized sharpening (only for hand strops), but a member of British Blades passed on a warning to me that he received from an English company specializing in polishing equipment, that in the professional world home-made MDF Wheels are considered too dangerous to use.
It seems that they can come apart suddenly due to the centrifugal forces most benchgrinders can create.
It seems that they can come apart suddenly due to the centrifugal forces most benchgrinders can create.
I own several vintage Gerbers in M2 steel, both outdoor & kitchen models, and this Durendal slicer model from the '60's does duty in our kitchen.
Opening all kinds of paper & plastic food packages, slicing bags with espresso beans, cutting up larger fruits like melons & pineapples, slicing bread loafs and hamburger buns without crumbling, cutting sausages, etc.
Not every day, but at least several times a week.
I bought this Gerber about 2 years ago on the Bay completely blunt, so i reprofiled & sharpened it with a SiC grit Paper Wheel, then refined the edge with 15 micron diamond compound on a second Paper Wheel, and then again with 6 micron diamond compound on a third Paper Wheel.
The tiny burr was removed with a fourth Paper Wheel coated with 0,25 micron diamond compound.
The idea was to get something of a semi-polish that would protect the exposed M2 edge better against corrosion issues during kitchen use, while still having some degree of bite.
The knife was then used for about 2 years in our kitchen, and when not in use stored on a magnet strip on our kitchen wall.
After those 2 years the edge only had a few very minor dings/flat spots in it (in the tiny belly area), but it could still shave the hair on the back of my hand on skin level quite well with about 90-95 % of the edge.
When cutting tomatoes however the edge tended to slide a bit over the skin before it started to cut.
The main reason for this kind of edgeholding is of course the fact that most of the edge on a slicer like this never touches a cutting board, only the belly area does, but the M2 steel performed quite admirably in my book.
A few weeks ago i resharpened the edge, this time only with 15 micron diamond compound, then deburred with 0,25 micron diamond compound, as i want to try the knife with some more bite.
Will have to find out if there will be corrosion issues or not.
So far i've only used it on food packaging (both paper & plastic, no fruit or other things yet), but here are a few pics how the knife & edge look now.
The edge feels sticky and is still treetopping sharp.
Specs:
Blade steel: hard chromed M2 steel
Hardness: 60-62 HRC
Handle material: cast on aluminum, chromed.
Overall length: 29,5 cm
Blade length: 16,5 cm
Blade thickness: 1,36 mm in front of the handle tapering to 0,84 mm close to the point
Thickness behind the edge: 0,5 mm
Edge angle: +/- 30 degrees inclusive, slightly convex
Opening all kinds of paper & plastic food packages, slicing bags with espresso beans, cutting up larger fruits like melons & pineapples, slicing bread loafs and hamburger buns without crumbling, cutting sausages, etc.
Not every day, but at least several times a week.
I bought this Gerber about 2 years ago on the Bay completely blunt, so i reprofiled & sharpened it with a SiC grit Paper Wheel, then refined the edge with 15 micron diamond compound on a second Paper Wheel, and then again with 6 micron diamond compound on a third Paper Wheel.
The tiny burr was removed with a fourth Paper Wheel coated with 0,25 micron diamond compound.
The idea was to get something of a semi-polish that would protect the exposed M2 edge better against corrosion issues during kitchen use, while still having some degree of bite.
The knife was then used for about 2 years in our kitchen, and when not in use stored on a magnet strip on our kitchen wall.
After those 2 years the edge only had a few very minor dings/flat spots in it (in the tiny belly area), but it could still shave the hair on the back of my hand on skin level quite well with about 90-95 % of the edge.
When cutting tomatoes however the edge tended to slide a bit over the skin before it started to cut.
The main reason for this kind of edgeholding is of course the fact that most of the edge on a slicer like this never touches a cutting board, only the belly area does, but the M2 steel performed quite admirably in my book.
A few weeks ago i resharpened the edge, this time only with 15 micron diamond compound, then deburred with 0,25 micron diamond compound, as i want to try the knife with some more bite.
Will have to find out if there will be corrosion issues or not.
So far i've only used it on food packaging (both paper & plastic, no fruit or other things yet), but here are a few pics how the knife & edge look now.
The edge feels sticky and is still treetopping sharp.
Specs:
Blade steel: hard chromed M2 steel
Hardness: 60-62 HRC
Handle material: cast on aluminum, chromed.
Overall length: 29,5 cm
Blade length: 16,5 cm
Blade thickness: 1,36 mm in front of the handle tapering to 0,84 mm close to the point
Thickness behind the edge: 0,5 mm
Edge angle: +/- 30 degrees inclusive, slightly convex
Hinderer XM-18 Slicer grind in S35VN steel.
According to my Tormek angle gauge the factory edge angle measured between 45 and 50 degrees inclusive, while the thickness of the steel just behind that edge went from 0.7 mm at the heel to 0.6 mm at the tip.
The knife is going to be used as a hunting folder, and the owner had 2 wishes: if possible no visually wide bevels, plus he wanted to be able to maintain the new edge on a Spyderco Sharpmaker.
Before sharpening:
After sharpening.
Edge reprofiled to an almost exact 35 degrees inclusive with a Paper Wheel coated with 220 grit SiC, after which the burr was removed with a second Paper Wheel coated with 0.25 micron diamond compound.
The new edge is what i would call sticky sharp.
According to my Tormek angle gauge the factory edge angle measured between 45 and 50 degrees inclusive, while the thickness of the steel just behind that edge went from 0.7 mm at the heel to 0.6 mm at the tip.
The knife is going to be used as a hunting folder, and the owner had 2 wishes: if possible no visually wide bevels, plus he wanted to be able to maintain the new edge on a Spyderco Sharpmaker.
Before sharpening:
After sharpening.
Edge reprofiled to an almost exact 35 degrees inclusive with a Paper Wheel coated with 220 grit SiC, after which the burr was removed with a second Paper Wheel coated with 0.25 micron diamond compound.
The new edge is what i would call sticky sharp.
This special version of the Spyderco Paramilitary 2 in CPM-M4 steel & carbon fiber is in use with a Dutch knife forum member.
A small fraction of the tip had broken off and the apex sustained some damage (see pic 3)
This is how the knife looked before sharpening.
You can click 2 X on each pic for more detail.
After sharpening.
First i ground the old apex flat on the Tormek Blackstone until all damage in the apex was gone & there was a new point.
Then i made a new edge with 15 micron diamond compound on a Paper Wheel, which was then refined with 6, 3, and 1 micron diamond compound on dedicated Paper Wheels to a full mirror.
The new edge measures 30 degrees inclusive and is hairwhittling sharp.
You can click 2 X on each pic for more detail.
A small fraction of the tip had broken off and the apex sustained some damage (see pic 3)
This is how the knife looked before sharpening.
You can click 2 X on each pic for more detail.
After sharpening.
First i ground the old apex flat on the Tormek Blackstone until all damage in the apex was gone & there was a new point.
Then i made a new edge with 15 micron diamond compound on a Paper Wheel, which was then refined with 6, 3, and 1 micron diamond compound on dedicated Paper Wheels to a full mirror.
The new edge measures 30 degrees inclusive and is hairwhittling sharp.
You can click 2 X on each pic for more detail.
Dustar Model 1 Arad 67 Commemorative combat knife from a collector.
The factory "edge" was very rough and also still had a burr so thick that i could lift the entire knife from the table by hooking it with my finger nail.
Edge angle was +/- 45 degrees inclusive which i left intact as the owner did not want wider bevels.
After grinding the apex flat on the Tormek Blackstone the edge was resharpened on a Paper Wheel with 15 micron diamond compound then deburred with a second Paper Wheel with 3 micron diamond compound, an the new edge can just treetop the hairs on the back of my hand.
Probably the most wear resistant D2 steel i have sharpened so far.
The factory "edge" was very rough and also still had a burr so thick that i could lift the entire knife from the table by hooking it with my finger nail.
Edge angle was +/- 45 degrees inclusive which i left intact as the owner did not want wider bevels.
After grinding the apex flat on the Tormek Blackstone the edge was resharpened on a Paper Wheel with 15 micron diamond compound then deburred with a second Paper Wheel with 3 micron diamond compound, an the new edge can just treetop the hairs on the back of my hand.
Probably the most wear resistant D2 steel i have sharpened so far.
This vintage Al Mar Applegate Fairbairn dagger from a display collection had factory edges which were rather coarse, had a few flat spots, and a flattened point.
Since the "R" from Rex Applegate's signature was already quite close to the +/- 50 degrees inclusive factory edge i chose not to reprofile but instead just polish the existing bevels a bit with successively 15.0 micron, 3.0 micron, and 1.0 micron diamond compound on dedicated Paper Wheels.
Both new edges can shave the hair on the back of my hand on skin level.
( click each pic 2 x for a bit more detail)
Since the "R" from Rex Applegate's signature was already quite close to the +/- 50 degrees inclusive factory edge i chose not to reprofile but instead just polish the existing bevels a bit with successively 15.0 micron, 3.0 micron, and 1.0 micron diamond compound on dedicated Paper Wheels.
Both new edges can shave the hair on the back of my hand on skin level.
( click each pic 2 x for a bit more detail)
Another PM2 in S110V.
The new edge was done on a Paper Wheel with 15 micron diamond compound, and then refined with 6.0 micron, 3.0 micron, and 1.0 micron diamond compound, all on dedicated Paper Wheels.
The apex is keen enough to whittle several curls in a row on one of my chest hairs while holding the hair at the root end only.
You can click each pic 2 X for a bit more detail.
The new edge was done on a Paper Wheel with 15 micron diamond compound, and then refined with 6.0 micron, 3.0 micron, and 1.0 micron diamond compound, all on dedicated Paper Wheels.
The apex is keen enough to whittle several curls in a row on one of my chest hairs while holding the hair at the root end only.
You can click each pic 2 X for a bit more detail.
The owner of this Maxamet PM2 had given his knife a forced patina treatment, and besides coming out a bit uneven the acid had also completely eaten away the factory apex as well as the very tip of the blade.
To say that the knife was completely blunt would have been an understatement.
The request was to give the knife a new toothy edge with a lot of bite while making it as sharp as possible.
(You can click each pic 2 X for a bit more detail)
Before sharpening:
After sharpening
Flattened the acid damaged "apex" some more on a 3000 grit diamond plate so i could start with fresh steel, then made a new edge on a Rubber Wheel coated with +/- 230 grit diamond powder & wax, then deburred on a Paper Wheel with 1.0 micron diamond paste & oil.
The new edge is ever so slightly convex, the new apex fits almost exactly in the 30 degree inclusive slot of my Tormek WM200 Angle Master, plus it can whittle one of my chest hairs at about 5.5 centimeters from the point of holding. (i don't own a BESS tester)
The somewhat "fuzzy" shoulders of the new edge show how deep the acid has eaten away into the sides of the blade in some area's.
To say that the knife was completely blunt would have been an understatement.
The request was to give the knife a new toothy edge with a lot of bite while making it as sharp as possible.
(You can click each pic 2 X for a bit more detail)
Before sharpening:
After sharpening
Flattened the acid damaged "apex" some more on a 3000 grit diamond plate so i could start with fresh steel, then made a new edge on a Rubber Wheel coated with +/- 230 grit diamond powder & wax, then deburred on a Paper Wheel with 1.0 micron diamond paste & oil.
The new edge is ever so slightly convex, the new apex fits almost exactly in the 30 degree inclusive slot of my Tormek WM200 Angle Master, plus it can whittle one of my chest hairs at about 5.5 centimeters from the point of holding. (i don't own a BESS tester)
The somewhat "fuzzy" shoulders of the new edge show how deep the acid has eaten away into the sides of the blade in some area's.
The owner of this Sebenza 25 bought the knife brand new from a dealer in the Netherlands, but although he was and is still very pleased with the knife itself, he soon found that the factory edge didn't cut too well.
He tried to improve things with the help of a Spyderco Sharpmaker and a leather strop loaded with some green compound, but to no avail.
So he sent the knife to me, and the first thing i did was to measure the edge angle with my Tormek WM200 Angle Master.
According to this device the edge measured 50 degrees inclusive on the straight part of the edge, going up to 55 degrees inclusive from the belly to the point.(!)
This is how the knife looked before sharpening:
First i removed the apex of the old edge by cutting a few times lightly at a 90 degrees angle into an old silicon carbide stone, after which i reprofiled the edge freehand on my Tormek SB-250 Blackstone to an even 30 degrees inclusive.
This was followed by a Paper Wheel with 220 grit SiC to smoothen the grindlines made by the Tormek, then refined with a second Paper Wheel coated with 15 micron diamond compound, and finally removed the burr with a third Paper Wheel coated with 0.25 diamond compound. (this leaves the 15 micron scratch pattern intact as much as possible to preserve bite)
The resulting edge treetops the hair on the back of my hand, can slice single-ply toilet paper, and survives a few cuts into my laminated testblock without any visible damage (checked under bright light with the loupe in my Victorinox SwissChamp)
This is how the knife looks after sharpening:
He tried to improve things with the help of a Spyderco Sharpmaker and a leather strop loaded with some green compound, but to no avail.
So he sent the knife to me, and the first thing i did was to measure the edge angle with my Tormek WM200 Angle Master.
According to this device the edge measured 50 degrees inclusive on the straight part of the edge, going up to 55 degrees inclusive from the belly to the point.(!)
This is how the knife looked before sharpening:
First i removed the apex of the old edge by cutting a few times lightly at a 90 degrees angle into an old silicon carbide stone, after which i reprofiled the edge freehand on my Tormek SB-250 Blackstone to an even 30 degrees inclusive.
This was followed by a Paper Wheel with 220 grit SiC to smoothen the grindlines made by the Tormek, then refined with a second Paper Wheel coated with 15 micron diamond compound, and finally removed the burr with a third Paper Wheel coated with 0.25 diamond compound. (this leaves the 15 micron scratch pattern intact as much as possible to preserve bite)
The resulting edge treetops the hair on the back of my hand, can slice single-ply toilet paper, and survives a few cuts into my laminated testblock without any visible damage (checked under bright light with the loupe in my Victorinox SwissChamp)
This is how the knife looks after sharpening:
Right hand Takamura R2 Gyuto 210 mm from a local Chef, who got it as a birthday present from his wife.
The knife has already been used for two months in the commercial kitchen and it was time for it's first resharpening, which i did yesterday on a Paper Wheel with 15 micron diamond compound and then deburred on a second Paper Wheel with 0.25 micron diamond compound.
The idea was to make an edge that would do both slicing & pushcutting well, and also to remove as little steel as possible from the fine and thin R2/SG2 blade @ 63-64 HRC.
The new edge measures +/- 20 degrees inclusive and can whittle a chest hair from root-to-tip at about 4 centimeters from the point of holding, and after a few test cuts into a old piece of beechwood cutting board.
I took these pics with an old Ipad and actually wanted to erase them again as being not good enough until i enlarged the last picture twice.
At first i thought i saw small dirt spots on the new bevel, but those tiny white specks were actually the sliced off peaks of the micro-dot structure on the inside of the flimsy plastic blade protector sleeve.
The owner of the Takamura R2 just sent me the link to this clip, in which he uses a grape to test the new edge:
https://m.youtube.com/watch?v=ID9KZW0d9ss&feature=youtu.be
Update:
According to the Chef this edge done on Paper Wheels lasted him 2 months in his commercial kitchen, which was just as long as the factory edge had lasted him.
During that time he sometimes touched up the edge by stropping it on an MDF strop with 1.0 micron diamond compound until that no longer worked satisfactory (in the last week or so), after which he used a fine ceramic rod on it.
Differences with the factory edge were that the Paper Wheel edge had a slightly smaller edge angle (+/- 20 degrees inclusive instead of +/- 22,5 degrees inclusive), was finer polished, and had a higher sharpness.
We're still in the process of finetuning the edge to his specific requirements, and next time he brings in the knife it will probably get a little less refined edge to see if it's useful life can be prolonged a bit more.
In his kitchen the real edge killers are the mandatory plastic cutting boards which are very abrasive on knife edges, together with the almost unavoidable tiny sand particles which sometimes remain in the huge quantities of vegetables that need to be processed.
The knife has already been used for two months in the commercial kitchen and it was time for it's first resharpening, which i did yesterday on a Paper Wheel with 15 micron diamond compound and then deburred on a second Paper Wheel with 0.25 micron diamond compound.
The idea was to make an edge that would do both slicing & pushcutting well, and also to remove as little steel as possible from the fine and thin R2/SG2 blade @ 63-64 HRC.
The new edge measures +/- 20 degrees inclusive and can whittle a chest hair from root-to-tip at about 4 centimeters from the point of holding, and after a few test cuts into a old piece of beechwood cutting board.
I took these pics with an old Ipad and actually wanted to erase them again as being not good enough until i enlarged the last picture twice.
At first i thought i saw small dirt spots on the new bevel, but those tiny white specks were actually the sliced off peaks of the micro-dot structure on the inside of the flimsy plastic blade protector sleeve.
The owner of the Takamura R2 just sent me the link to this clip, in which he uses a grape to test the new edge:
https://m.youtube.com/watch?v=ID9KZW0d9ss&feature=youtu.be
Update:
According to the Chef this edge done on Paper Wheels lasted him 2 months in his commercial kitchen, which was just as long as the factory edge had lasted him.
During that time he sometimes touched up the edge by stropping it on an MDF strop with 1.0 micron diamond compound until that no longer worked satisfactory (in the last week or so), after which he used a fine ceramic rod on it.
Differences with the factory edge were that the Paper Wheel edge had a slightly smaller edge angle (+/- 20 degrees inclusive instead of +/- 22,5 degrees inclusive), was finer polished, and had a higher sharpness.
We're still in the process of finetuning the edge to his specific requirements, and next time he brings in the knife it will probably get a little less refined edge to see if it's useful life can be prolonged a bit more.
In his kitchen the real edge killers are the mandatory plastic cutting boards which are very abrasive on knife edges, together with the almost unavoidable tiny sand particles which sometimes remain in the huge quantities of vegetables that need to be processed.
Zuletzt bearbeitet:
Some time ago one of the Chefs i sharpen kitchen knives for decided to treat himself to a brand new Sebenza 25 from a well known Dutch knife shop.
As many here know the Sebenza is a beautifully designed & manufactured knife, and the model 25 is no exception.
Sadly the factory edge on the first example the Chef got to handle was just plain blunt, and upon inspection it turned out that the other 4 or 5 Sebenza's 25 that the shop had in stock suffered from a comparable bluntness.
To cut a long story short: in the end the Chef liked the knife so much that he just bought the least blunt one, while the shop assistant promised to contact CRK to see if the other knives could be sent back.
The day after buying the knife the Chef visited me to ask if i could do something about the edge.
The first thing i noticed about the blade on his model 25 is that it seemed to be ground a hair thinner behind the edge compared to previous Sebenza's 25 that i've handled and sharpened, and that as a result the edge bevels were quite narrow, even with a measured inclusive edge angle of 35 degrees.
The second thing i noticed (with my Victorinox loupe) was that the edge reflected light almost along it's entire length, and i couldn't even cut a piece of copy paper with it.
I think that the edge wasn't completely apexed, but with only my loupe to judge by i'm not 100 % sure.
In a conversation with the owner and also because the knife was brand new we came to the conclusion to give it a new edge that would resemble the factory edge as much as possible, and to make it seem as best as i could that nothing was done to the knife.
First i removed the blunt apex of the factory edge by cutting several times into a silicon carbide stone, after which i gave it a completely new edge with an experimental Rubber Wheel coated with 230 grit diamond powder & wax, after which i removed the tiny burr with a Paper Wheel with 1 micron diamond compound.
The new edge again measured 35 degrees inclusive from heel to tip, survived a few cuts into my laminated test block without visible damage to the apex, which could then still easily treetop the hair on the back of my hand.
And most importantly, the Chef was happy with how his new knife turned out,
Before sharpening:
After sharpening:
As many here know the Sebenza is a beautifully designed & manufactured knife, and the model 25 is no exception.
Sadly the factory edge on the first example the Chef got to handle was just plain blunt, and upon inspection it turned out that the other 4 or 5 Sebenza's 25 that the shop had in stock suffered from a comparable bluntness.
To cut a long story short: in the end the Chef liked the knife so much that he just bought the least blunt one, while the shop assistant promised to contact CRK to see if the other knives could be sent back.
The day after buying the knife the Chef visited me to ask if i could do something about the edge.
The first thing i noticed about the blade on his model 25 is that it seemed to be ground a hair thinner behind the edge compared to previous Sebenza's 25 that i've handled and sharpened, and that as a result the edge bevels were quite narrow, even with a measured inclusive edge angle of 35 degrees.
The second thing i noticed (with my Victorinox loupe) was that the edge reflected light almost along it's entire length, and i couldn't even cut a piece of copy paper with it.
I think that the edge wasn't completely apexed, but with only my loupe to judge by i'm not 100 % sure.
In a conversation with the owner and also because the knife was brand new we came to the conclusion to give it a new edge that would resemble the factory edge as much as possible, and to make it seem as best as i could that nothing was done to the knife.
First i removed the blunt apex of the factory edge by cutting several times into a silicon carbide stone, after which i gave it a completely new edge with an experimental Rubber Wheel coated with 230 grit diamond powder & wax, after which i removed the tiny burr with a Paper Wheel with 1 micron diamond compound.
The new edge again measured 35 degrees inclusive from heel to tip, survived a few cuts into my laminated test block without visible damage to the apex, which could then still easily treetop the hair on the back of my hand.
And most importantly, the Chef was happy with how his new knife turned out,
Before sharpening:
After sharpening:
An older one, a user custom Jens Anso from a Dutch knifeforum member after a tune-up by a Dutch knifemaker.
Part of the tune-up was a two-step stonewash treatment of the RWL34 blade, which unavoidably also removed the original edge.
I put on a new edge using a standard Paper Wheel with silicon carbide grit, refined it with a second Paper Wheel coated with 15 micron diamond paste, and finally removed the very small burr on the Tormek leather wheel with some 1 micron diamond compound
This leaves an edge that looks almost polished, but has more bite than when finished with the polishing Paper Wheel using standard aluminum oxide.
Before sharpening:
After sharpening:
Part of the tune-up was a two-step stonewash treatment of the RWL34 blade, which unavoidably also removed the original edge.
I put on a new edge using a standard Paper Wheel with silicon carbide grit, refined it with a second Paper Wheel coated with 15 micron diamond paste, and finally removed the very small burr on the Tormek leather wheel with some 1 micron diamond compound
This leaves an edge that looks almost polished, but has more bite than when finished with the polishing Paper Wheel using standard aluminum oxide.
Before sharpening:
After sharpening:
A while ago i sharpened this Buck Hartsook in S30V steel for a Dutch forum member:
The edge was done on Paper Wheels with diamond compounds exclusively, and the new & slightly convex edge measures +/- 30 degrees inclusive.
Remarkably useful little knives with well hardened S30V steel.
The edge was done on Paper Wheels with diamond compounds exclusively, and the new & slightly convex edge measures +/- 30 degrees inclusive.
Remarkably useful little knives with well hardened S30V steel.
A Strider SMF with S110V blade from a Dutch forum member.
According to my Tormek angle gauge the old edge measured +/- 40 degrees inclusive from the heel to half an inch before the tip where it changed into 45 degrees inclusive.
The owner uses this knife mostly to cut various kinds of green wood & twigs in horticulture, and had already tried his hand at reprofiling the edge himself with a DMT Diafold.
Together we came to the conclusion that the edge could do with a full reprofiling, as well as with a finer edge finish to better suit his specific purposes.
BTW: the owner also contacted Duane Dwyer by mail, among other things to ask him about the hardness of this S110V blade, and according to Duane it measures 61 HRC.
This was the knife before sharpening:
After reprofiling & sharpening.
The new edge angle came out at +/- 32 degrees inclusive along the entire edge, and it can treetop armhair and slice single ply toilet paper.
Probably due to having the flu at the moment my hands didn't do exactly what i wanted them to do, and as a result i didn't manage to get both bevels completely symmetrical.
Grit progression: a Paper Wheel with 220 grit SiC for reprofiling, a second Paper Wheel with 15 micron diamond compound for refining, and a third Paper Wheel with 0.25 micron diamond compound for removing the tiny burr.
According to my Tormek angle gauge the old edge measured +/- 40 degrees inclusive from the heel to half an inch before the tip where it changed into 45 degrees inclusive.
The owner uses this knife mostly to cut various kinds of green wood & twigs in horticulture, and had already tried his hand at reprofiling the edge himself with a DMT Diafold.
Together we came to the conclusion that the edge could do with a full reprofiling, as well as with a finer edge finish to better suit his specific purposes.
BTW: the owner also contacted Duane Dwyer by mail, among other things to ask him about the hardness of this S110V blade, and according to Duane it measures 61 HRC.
This was the knife before sharpening:
After reprofiling & sharpening.
The new edge angle came out at +/- 32 degrees inclusive along the entire edge, and it can treetop armhair and slice single ply toilet paper.
Probably due to having the flu at the moment my hands didn't do exactly what i wanted them to do, and as a result i didn't manage to get both bevels completely symmetrical.
Grit progression: a Paper Wheel with 220 grit SiC for reprofiling, a second Paper Wheel with 15 micron diamond compound for refining, and a third Paper Wheel with 0.25 micron diamond compound for removing the tiny burr.
A small black ceramic backlock folder without any markings (Böker ?) i did in 2013.
This well made knife had practically no edge and no point to speak of when i received it, and even opening mail with it was difficult.
I used the Tormek Blackstone graded to around 1000 grit for freehand reprofiling, followed by 3 Paper Wheels coated with 15, 6.0 and 3.0 micron diamond compounds for refining & polishing.
The new edge fits in the 30 degrees inclusive slot on my Tormek angle gauge, is slightly convex, and can shave the hair on my leg in both directions.
Specs:
Length open: 12,0 cm
Length closed: 7,5 cm
Blade material: black zirconium oxide
Blade length: 4,5 cm
Blade thickness: 2,0 mm
Handle material: Ivory Micarta & Nickel Silver bolsters
Weight: 61 grams
This well made knife had practically no edge and no point to speak of when i received it, and even opening mail with it was difficult.
I used the Tormek Blackstone graded to around 1000 grit for freehand reprofiling, followed by 3 Paper Wheels coated with 15, 6.0 and 3.0 micron diamond compounds for refining & polishing.
The new edge fits in the 30 degrees inclusive slot on my Tormek angle gauge, is slightly convex, and can shave the hair on my leg in both directions.
Specs:
Length open: 12,0 cm
Length closed: 7,5 cm
Blade material: black zirconium oxide
Blade length: 4,5 cm
Blade thickness: 2,0 mm
Handle material: Ivory Micarta & Nickel Silver bolsters
Weight: 61 grams
Another oldie from 2013.
A niece of mine is an avid amateur Chef (but not yet a knife afi), and this black ceramic knife is one of her favorites in the kitchen.
Longtime use however (not always on a suitable cutting board) plus storing it unprotected in a drawer between a bunch of steel bladed knives had blunted the edge to a point next to unusable, complete with quite a lot of (micro) chips and a broken tip.
This is the knife as it was when i received it.
(when you click the pictures 2 x you can see the chipping & the damaged point clearly)
This is the knife after sharpening.
Removing the chips and setting the new bevel was done with a Tormek T7 fitted with an SB-250 Blackstone, refining with a Paper Wheel coated with 15 micron diamond compound, and semi-polishing with a second Paper Wheel coated with 6 micron diamond compound.
The new slightly convex edge measures +/- 25 degrees inclusive, and the sharpness is just hairwhittling (only towards the root, not to the point)
It easily slices single layer toiletpaper (torn apart 3-layered version) and a tomato of course.
Specs:
Overall length: 28,0 cm
Blade length: 14,8 cm
Blade thickness: 1,84 mm
Blade type: black ceramic / saber-hollow
Thickness behind the edge: 0,4 mm
The first clip shows the slicing of a piece of standard 3-layered toilet paper, for the second clip i peel off 1 layer and slice the remaining 2 layers, and the third clip shows the slicing of just the remaining single layer of toilet paper:
http://www.youtube.com/watch?v=Ubg_drYHoKE
http://www.youtube.com/watch?v=hUkKfwGFogY
http://www.youtube.com/watch?v=RSkxPA9BK8E
Slicing a tomato:
http://www.youtube.com/watch?v=R3-A0SMcIbw
A niece of mine is an avid amateur Chef (but not yet a knife afi), and this black ceramic knife is one of her favorites in the kitchen.
Longtime use however (not always on a suitable cutting board) plus storing it unprotected in a drawer between a bunch of steel bladed knives had blunted the edge to a point next to unusable, complete with quite a lot of (micro) chips and a broken tip.
This is the knife as it was when i received it.
(when you click the pictures 2 x you can see the chipping & the damaged point clearly)
This is the knife after sharpening.
Removing the chips and setting the new bevel was done with a Tormek T7 fitted with an SB-250 Blackstone, refining with a Paper Wheel coated with 15 micron diamond compound, and semi-polishing with a second Paper Wheel coated with 6 micron diamond compound.
The new slightly convex edge measures +/- 25 degrees inclusive, and the sharpness is just hairwhittling (only towards the root, not to the point)
It easily slices single layer toiletpaper (torn apart 3-layered version) and a tomato of course.
Specs:
Overall length: 28,0 cm
Blade length: 14,8 cm
Blade thickness: 1,84 mm
Blade type: black ceramic / saber-hollow
Thickness behind the edge: 0,4 mm
The first clip shows the slicing of a piece of standard 3-layered toilet paper, for the second clip i peel off 1 layer and slice the remaining 2 layers, and the third clip shows the slicing of just the remaining single layer of toilet paper:
http://www.youtube.com/watch?v=Ubg_drYHoKE
http://www.youtube.com/watch?v=hUkKfwGFogY
http://www.youtube.com/watch?v=RSkxPA9BK8E
Slicing a tomato:
http://www.youtube.com/watch?v=R3-A0SMcIbw