Yesterday one of the Chefs i sharpen kitchen knives for on a regular basis 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 may very well be considered the current king of the hill in the series.
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.
Anyway, today the Chef contacted me to ask if i could do something about the edge on his knife.
The first thing i noticed about the blade on his model 25 is that it seems 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.
Now 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 is 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 with 230 grit diamond powder.
Finally i removed the tiny burr with a Paper Wheel with 1 micron diamond compound.
The new edge again measures 35 degrees inclusive from heel to tip, survives a few cuts into my laminated test block without visible damage, and can still easily treetop the hair on the back of my hand.
I think the owner will be happy when he comes to collect his knife tomorrow morning.
Before sharpening:
After sharpening:
