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.

[William Fretwell]

Yes it is most interesting to see what you are doing! My stereoscopic microscope goes up to 90 times but I use 40 mostly.
Once you have examined your standard technique and literally get a feel for the results as you progress you need not view very often. It does help to know when you reach the end of the process.
Different sharp, the two sided technique etc are relevant to what you are cutting. Creating serrations on one side, then sharpening them to perfection on the other will create a wonderful ‘bread knife’ where the blade is dragged and pushed perpendicular to the edge. Pushing the blade parallel however will create gulleys.
I have a cast cobalt knife with dendritic cobalt carbide in the casting. Sharpening the edge does not achieve a razor edge but for cutting rope it can not be beat and the edge lasts. That is it’s main attraction, yes it cuts cheese!

Sharp is relevant to what you are cutting and how the edge is used. The steel is relevant to how long the sharpest edge obtainable lasts. Have a look, refine your technique, what you do won’t be drastically different but you feel good!

[Jim Koepke]

To paraphrase Forest Gump, "sharpness is as sharpness does."

If an edge, whether it be on a plane, chisel, razor or knife can do what its user wants it to do, then it is probably sharp enough.

Guess I'll need to get myself to an arm chair now.

jtk

[Andrew Pitonyak]

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

Consider me in the very middle of Ohio (Columbus). Steven is probably 40 minutes (or a bit more) due west, so, further away from PA.

That should put you roughly 3.5 hours from me

[Andrew Pitonyak]

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

Yeah, love this site!

[Andrew Pitonyak]

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 think he is talking about a guy who knows about metals, so he should have a wee bit of book learning on the subject! :-)

As for you sir, I think that you use Magic when you sharpen. As an example, I hand Steven a blade and say "here hold this", I do something and he hands it back and it is sharper. Steven claims he "stropped it", you know, on jeans, on his hands, who knows.... I need to setup hidden cameras or something. All I know is that it cuts better. I need to use those fancy magnifying things to look at the edge. :D

The primary target for my initial post was because somebody had posted that they were doing all these things and it seemed that things simply did not get sharper. He eventually tracked the problem down to a wire edge. I had that problem when I first tried Arkansas stones and people here helped me learn about "chasing the burr", something I had not had to do to get a sharp edge on my water stones; mostly Shapton.

In that context, even a 10x loop would probably have shown the burr. For certain a USB thing with higher magnification certainly would have. And this is why the original post was very simplistic. Just a few simple tips that I use all the time and it really helped me a lot.

[Andrew Pitonyak]

Yes it is most interesting to see what you are doing! My stereoscopic microscope goes up to 90 times but I use 40 mostly.
Once you have examined your standard technique and literally get a feel for the results as you progress you need not view very often. It does help to know when you reach the end of the process.

I still have to look, well, mostly when I am restoring an edge on a knife so that I can easily see if I actually made it to the edge (marker). For certain the more you do it the less you need to look.

BTW, you made some interesting points that I cut-off in my quote. <tip hat>

[steven c newman]

Hmmmm, not sure...but I think Andrew just dumped a big bucket of ice cold water on a couple Flames?

[John C Cox]

A general suspicion based on my own experience... I wonder how many people complain about steel when their problem is really something else, like wire edges or unfavorable geometry. It is only after you overcome stuff like this that differences in the steel really become meaningful.

[Edward Weber]

A general suspicion based on my own experience... I wonder how many people complain about steel when their problem is really something else, like wire edges or unfavorable geometry. It is only after you overcome stuff like this that differences in the steel really become meaningful.

I agree,
The same is true with turning tools as well.