Inspecting an edge; markers and magnifiers

[Andrew Pitonyak]

Two things have significantly improved my sharpening, a black marker and a magnifier.

I sharpen many knives, probably 50 blades last week and I do not feel like I made a dent in my box of knives to sharpen.


Especially when I am creating a new profile (changing the angle), I like to mark both sides with a marker. This provides a very clear idea of where I am removing metal and makes it easier to see when I make it to the very edge. You can also feel for the edge that is created.


The next item has to do with a visual inspection. Especially when I am close to the edge, my old eyes can miss areas, so I like to use magnification.


I really like a 10X Loupe such as the Carson LumiLoupe 10X Power Stand Magnifier (LL-10), Black/Clear for $9.


https://www.amazon.com/gp/product/B000CAHCQS


I even have one with LED lights for $14 but I usually use the other 10X.


https://www.amazon.com/gp/product/B088D6PPLM


If you place a loupe magnifier on a piece of paper, it is in focus (or should be). This means that I directly set the loupe on blade when I look. You can also get an old school type for $7.


https://www.amazon.com/gp/product/B01HZUKF2A


When I want better magnification and pictures, I use a USB device. I think that most of them are about the same for about $25. I chose


Jiusion Original 40-1000X USB Microscope with Portable Carrying Case, Digital Magnification Endoscope Camera 8 LEDs Metal Base for Micro USB USB-C Android, Windows Mac Linux Chrome


Because it has both USB-A and USB-C, which means I can easily connect to my Linux computer and my Android Phone.


https://www.amazon.com/gp/product/B07DRGR6LX


I then spent another $22 on an adjustable stand


https://www.amazon.com/gp/product/B0797PPX8D


There are many choices.


I like to test my blades by slicing paper. I always use news print because it is fine and more difficult to slice than say printer paper. Paper has grain and it is easier to cut in one direction than the other.


This video shows 5 methods to test for the grain direction.


https://www.youtube.com/watch?v=cO_HAeH7pGw


I won’t bother posting images of edges off different sharpening medium, but you can see the difference in scratch patterns as well as wire edges. I can say that if you really want to see what a nice edge looks like, take a look at a Flex Cut tool with a factory edge.


That said, if people really want to see images of these things, I will generate some if I do not have them just sitting around.

[Stephen Rosenthal]

Previously I used a Schneider photographer’s loupe, but now I use the magnifier on my iPhone. The zoom and autofocus are game changers.

[Cameron Wood]

Nice tips.

My final inspector is a little 40x microscope- about the size of a ball point pen, but clip on/flip up 4x magnifiers are used the most.

[steven c newman]

Andrew has seen in-person, what and how I sharpen with....and the results....

And, more than welcome to stop by sometime, again...

[Patrick Baney]

Out of curiosity, how far are you from Erie pa?

[Larry Frank]

There is an interesting paper called "Experiments on Knife Sharpening" by Dr. John Verhoeven. It shows great SEM pictures of edges sharpened with different methods.

Dr. Verhoeven is A metalllurgist who also rediscovered how to make REAL Damascus steel.

[Charles Guest]

There is an interesting paper called "Experiments on Knife Sharpening" by Dr. John Verhoeven. It shows great SEM pictures of edges sharpened with different methods.

Dr. Verhoeven is A metalllurgist who also rediscovered how to make REAL Damascus steel.

I'm going to wait for the armchair metallurgists with no professional training at all to weigh-in.

[Warren Mickley]

I'm going to wait for the armchair metallurgists with no professional training at all to weigh-in.

I have to agree with you Charles. The guy seems to think that because he is a metallurgist he can expound on sharpening without experience. As an example, he talks about straight razors; I doubt he ever used one, let alone learned to sharpen and maintain one, or gained any insight. You can't sharpen very well sitting in an armchair.

[Rafael Herrera]

More logs for the pyre can be found here: https://scienceofsharp.com/home/

[steven c newman]

Starting to sound like he already arrived.....So...who is all this "flame" directed at? Slow day at the Ivory Towers?

BTW..I have met with Andrew...and yes he does know of what he speaks....certain others on here haven't , nor have the slightest CLUE as to what Andrew does or does not know....Same old, same old....

[Edward Weber]

Starting to sound like he already arrived.....So...who is all this "flame" directed at? Slow day at the Ivory Towers?

BTW..I have met with Andrew...and yes he does know of what he speaks....certain others on here haven't , nor have the slightest CLUE as to what Andrew does or does not know....Same old, same old....

I can't tell if it's metallurgists who don't sharpen or woodworkers who sharpen but aren't proffesional metallurgists that are ticking everyone off.
Or is it just everyone
Get off my grass

[Larry Frank]

I enjoy reading the sharpening thread for all the experts on them. These type of threads seem to attract the greatest animosity of almost any subject than Sawstop.

Just for general interest, I am a metalllurgist and have sharpened all kinds of things including a straight razor. I did not sit in an armchair but spent most of my time actually making steel in an electric furnace shop. Dr. Verhoeven was not an armchair type and spent a long time working with a blade smith actually recreating how real Damascus steel was made and sharpened.

I will stay out of these threads and let the "experts" provide their opinions.

[Edward Weber]

Larry, I read the Experiments on Knife Sharpening, thanks

[Chuck Hill]

Thank you, Rafael. That is a very interesting site!

[Charles Guest]

I have to agree with you Charles. The guy seems to think that because he is a metallurgist he can expound on sharpening without experience. As an example, he talks about straight razors; I doubt he ever used one, let alone learned to sharpen and maintain one, or gained any insight. You can't sharpen very well sitting in an armchair.

I was actually thinking of other armchair metallurgists, but I do see your point.