Sharpness loss in storage, and recovery with cutting

[wootzblade]

We shot a video showing the phenomenon “sharpness improves with cutting” observed in the kitchen:

In cutting food, the knife does not become sharper, but rather restores to the edge sharpness it had before the knife storage. The spontaneous loss of sharpness during storage gets reversed as we start cutting, by stripping the oxidation layer off the edge.

I wrote about the spontaneous loss of sharpness in my Knife Deburring book, and have a lengthy video of the experiments:

 

[Twindog]

This is one of the reasons why I love Vanax Superclean: The edge doesn't degrade during storage.

 

[kreisler]

great practical research work on sharpness, very interesting results!

 

[HeavyHanded]

I haven't noticed this much with stainless. With carbon steels is fairly pronounced unless the edge is stored in a very low moisture environment.

I've switched to waxed leather for all my carbon steel knives and hatchets (haven't pulled that off with my machetes yet!) and stored on open shelf in my basement they come out of the sheath shaving sharp several years after being honed. Not testing beyond that though, they might have lost a bit.

 

[ToddS]

Vadim, have you ever experimented with the effect of lubricant on the BESS score? For example comparing a clean dry blade to one coated with oil or even just water?

 

[000Robert]

My Gerber Gator 650 that I bought 14 1/2 years ago still has its razor sharp factory edge on it. The steel is 154CM according to my research. You can see in the photo that there is no edge degradation.
In it's life it has only cut a few pieces of rope and twine, and opened a few boxes. And one time I cut a couple of windows out in the big cardboard box that my new recliner came in because the babies wanted to play in it, and wanted a couple of windows to look out of.
That's all it has cut. Over the years I would oil the blade once in a while. The edges have never touched a stone since it left the factory. And there isn't a speck of rust anywhere either. Age has not hurt the edges on this knife.

Edit: Well, maybe not razor sharp, but it slices magazine paper effortlessly.

 

[wootzblade]

Vadim, have you ever experimented with the effect of lubricant on the BESS score? For example comparing a clean dry blade to one coated with oil or even just water?

Hi Todd,
I tested some, when looking for a lubricant to seal sharpened edge before sending it to the customers who also have the BESS sharpness tester.
As seen from this table, the Anhydrous Lanolin showed the best and I used it in the experiments in the video

The part of the video Improving sharpness by oxidation control (Experiment #2) compares control knives to a sealed edge at 40:57