Simple Scratch Pattern Experiment

Hey all,

So I wanted a way to test how some of my different hones affect the scratch pattern on the metal. I used an old stainless steel throwing knife and flattened a section of the handle to see how it looks after different hones. I just used my scanner to take the pictures, so sorry that it couldn't be of higher quality. But I still think useful comparisons can be made. I know the scratch pattern alone doesn't tell you the quality of the stone or how finely it can sharpen a razor, but I still think it's interesting. :)

The order of the pictures is:

1) DMT 325
2) DMT 600
3) DMT 1200
4) Norton 4000
5) Norton 8000
6) Coticule (used with just water)
7) Yellow/Green Thuringian
8) Nakayama

The changes are pretty obvious in the first few, but from the thuringian to the nakayama there isn't that much of a difference. It looks a bit finer in the scanned pictures as well as in person, but it's not like a night and day thing.

Here they are!

EDIT: Looking at the pictures again I don't think I spent enough time on the naturals....I will look for another flat piece of metal I can test on, but one that isn't such a large area. I think it was too large of an area for the naturals to work on, well without a LOT of strokes that is. :) I was using a hard coticule, and I know that my nakayama is a slow one. When I try this experiment again I will post the results. Hopefully the progression from the naturals will be more obvious and less residual scratches will be left.

I only see 7 pics...
But an interesting exercise. Someone (Olivia, I think?) recently mentioned looking at scratch patterns using a CD case - it's not steel but it might work.

Yes, but actually the CD itself (the glossy side)
Great experiment, Dave, but whats distracting are the old scratches from the lower grit hones.
You would see each scratch pattern much better on a pristine surface.
If you go for a documentation of efficiency like removing old scratches, yours is the way to go of course.

Among the first 4, I only see a difference in the 4th one.
The first three look identical.
The last three also look identical.

I will indeed have to do another experiment to better show these results. The old scratches are definitely there and are distracting and make them all look pretty similar..... I will look around the house for a better medium to scratch up! Will report back...

Be prepared, LOL
I did it with acrylic squares of about 1 inch
They sucked themselves onto the hones like nothing else
and disrupted my original idea of same strokes with SAME pressure totally.
Better look for something that you can bend a little.

..what about something like a woodruff key or other little parts from the hdw store.

...Got a lot of stone to use up looks like. :) I'd say: save that natural slurry and lap time for something worthy-

Someone on here, did an similar experiement, with different hones and used steel washers...cheap and the surfaces are already somewhat polished...
Its a pretty cool thing to do...i will try it sometime too.

Thanks,

Mac

The Nakayama did terrible you need to send it to me---LOL! A very interesting experiment thanks.

Cool experiment. Here are photos that Tim Zowada did on bevels, edges and stone surfaces. They were in the Wiki help files but they seem to be disabled for some time now. :shrug:

At the risk of sounding dumb, why don't you take a piece of polished metal such as the spine of a knife or straight and start with the highest grit and work down to the lowest grit. In this way the previous scratch pattern will not interfere...or so it seems in my mind.

Quote:

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Originally Posted by JMS

At the risk of sounding dumb, why don't you take a piece of polished metal such as the spine of a knife or straight and start with the highest grit and work down to the lowest grit. In this way the previous scratch pattern will not interfere...or so it seems in my mind.

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Hmm....not a bad idea! I was trying to brainstorm ideas of how I could do a test, and I thought about having several items (such as metal washer as McWolf1969 mentioned), honing them to ensure that they're flat and finish on 8000 on all of them. So the scratches from the Norton 8000 will be my control for the experiment. Then each one can be used on a polishing stone to see how it affects the finish. One problem that I have is that I can only use a scanner to get decent pictures of the scratches (using the digital camera proved very ineffective) and it doesn't do a great job.

It was just something I was willing to play around with, but don't really feel like doing a full blown experiment. I feel lazy...:boohoo:Plus Tim Zowada already did a much better experiment! (Thanks for the link Jimmy).

I know how the scratches look under 30x on a bevel for the different stones, I just wanted to see if could get a picture of that somehow. I just use a little handheld microscope gadget-thingy, so I would need a proper microscope and a USB camera (or whatever you need to take digital pictures with the scope) which I don't feel like spending the money on. :p

Dave,

I think we were separated at birth!

As much as I liked Tim's experiment, it's unfair IMO, He says he took the same number of passes on each medium, which, as we all know is not the best way to compare the results of each medium.

The best way is to use one medium until it achieves the results you are looking for i.e. uniform scratches.

Here are some pics from "The Complete Guide to Sharpening" and "The Art of Japanese Sword Sharpening" that show the results of each of the mediums. I have more info on the books in my blog here.

In the Complete guide pics, they first polished the blades up to 8K (the most available at the time of publishing) and then "dumbed down" to show better the scratches of the stones. In the sword pics, I think it better shows the different levels of scratches. Pure XXX porn IMM:tu

Just wondering if there might be something wrong with me when I say that this is really beautiful, :dropjaw:
That hard arkansas....

Quote:

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Originally Posted by JimmyHAD

Cool experiment. Here are photos that Tim Zowada did on bevels, edges and stone surfaces. They were in the Wiki help files but they seem to be disabled for some time now. :shrug:

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Actually, Tim kindly allowed us to put them into the Wiki itself: Edges produced by various hones - Straight Razor Place Wiki.

With regards to the help files: We are working on it. Only, the file names were optimised for another Wiki extension, and we're still looking for a way to make them appear neatly again. Sorry for that, but we needed to upgrade the Wiki software to enable the "Create a Book" feature.