Topics

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 SB-250 Blackstone graded with diamond 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: 4.72 inches (12,0 cm)
Length closed: 2.76 inches (7,5 cm)
Blade material: black zirconium oxide
Blade length: 1.57 inches (4,5 cm)
Blade thickness: 2,0 mm
Handle material: Ivory Micarta & Nickel Silver bolsters
Weight: 61 grams

This traditional Argentinian Ju-Ca brand fixed blade belongs to a friend of a friend, and as you can see the point was broken off and the handle was also in need of a bit of TLC.

Website of the Argentinian father & son team, who have been making these knives since 1959: http://ju-ca.com.ar/

For quite a few years this Buck Strider 881 mini tanto in BG42 steel was gathering dust in a drawer, as to me it was more a knife-like object, literally unable to cut anything.
Over the last few weeks i changed that with the help of my Tormek SB-250 stone (for the point area), a 300 grit diamond file, a Foss 7205 black/green silicon carbide stone, and some 400 grit wet & dry SiC paper on glass (for the straight edge)
The apex on the now full convex blade measures somewhere between 22.5 and 25 degrees inclusive, and i'm first going to do some test cutting to find out if i can safely lower it a bit more.
Also rounded the overly sharp G10 grip plates a bit and sanded the screw heads.

Before:








While grinding the blade with the diamond file:







After the 400 grit SiC paper and removing the tiny burr on a piece of hard cardboard with a dab of 1.0 micron diamond paste:






Considering all work was done with only one eye currently functioning at about 80 % (plus a pair of reading glasses) i'm quite pleased with the result, :-)

Sometimes i remodel worn out or discarded meat carving knives into very narrow shank-like knives, which i then give away to certain Chefs & butchers.
This old Swibo i did a few years back, and it has quickly become the favorite bird & trout knife of a local Chef.

The rigid blade is hand convex ground up to 400 grit wet & dry SiC, it has an edge angle somewhere between 25 and 30 degrees inclusive, and the back of the blade is also convexed to a degree (which thins the blade a bit more & allows for better twisting & turning)
My Tormek T7 fitted with an SB-250 Blackstone was used in a supportive role; to grind down the back of the blade a bit before i continued with hand convex grinding.
The hard rubber-like handle has no real guard, only a few shallow finger grooves, which provide for quite a lot of grip.
Very useful knife according to it's owner.

On this knife the Tormek was not used for the actual sharpening of the edge, but in a very important supporting role.

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.















Total procedure:

- Repairing the point of the knife (about 2 mm was broken off) was done on the Tormek SB-250 stone by grinding the back of the blade until there was a new point.
- Flattening the old edge was also done on the Tormek (by grinding off about 1/10th of a mm on the side of the stone.
- Sharpening to burr was done exclusively on the 15 micron Paper Wheel.
- Deburring was done exclusively on the 0.25 micron Paper Wheel.
- Rounding the heel of the knife was again done on the Tormek (by grinding off a tiny bit of steel on the side of the stone.)

Currently doing a bit of tinkering, as in making my own version of Herman Trivilino's knife rest (using a cut-off piece of Torlock and 2 scrap pieces of aluminium), plus testing an MDF wheel with 1.0 micron diamond paste.
I'm already a bit further with the knife rest (ground in the hollow part on the SB-250 stone and put plastic tape on top to avoid scratching knife blades), and the first cheap knives i did came out quite well.
Probably going to replace the aluminium pieces with one piece of more rigid steel, but for now it seems to do the job.



The MDF Wheel is a testbed to find out what it can do exactly and how well.
I have been using MDF benchstrops with diamond compounds succesfully for quite some time now, and it was time to see if a motorized version would also work.
So far i found that it indeed works very well for removing burrs on harder & more wear resistant steel types (think S30V, ZDP-189, etc), as well as touching up existing edges on the same steels.
On softer steel types the leather wheel works noticeably better.
Also experimenting with various slots in the surface, both to trap steel debris as well as to find out if the direction of the slots has any influence in burr removal.
Will make a few more of these wheels in the future.