Ascending Stone Progression at 800x

[Mathew Whaley]

I’d be very interested in seeing the balsa results as well, in particular, how much pressure can be used before rounding the edge. My normal progression after sandpaper is 5, 3.5, 1, .5, .125, .05…..all on balsa. Even going as much as 100 passes on each though, I can never fully get rid of the sandpaper scratches with how lightly I contact the blade.

Id also like to see what effect blank cow leather has on an edge, if any.

[wickededge]

I can tell you already that kangaroo leather is the way to go if you’re interested in getting rid of all the scratches. Somewhere in these forums is a progression I did ending with kangaroo in which the edge is visually perfect at 500x. I’ve been able to repeat that result many times so I don’t believe it’s a fluke of camera angles or lighting.

I’d be very interested in seeing the balsa results as well, in particular, how much pressure can be used before rounding the edge. My normal progression after sandpaper is 5, 3.5, 1, .5, .125, .05…..all on balsa. Even going as much as 100 passes on each though, I can never fully get rid of the sandpaper scratches with how lightly I contact the blade.

Id also like to see what effect blank cow leather has on an edge, if any.

-Clay

[Tom Whittington]

Interesting info on rounding the edge a little. Would it be advisable for some situations to back off the arms a degree or so if you wanted to maintain really sharp geometry? I’m playing with an old Imperial filet knife as I type this and just finished the 1000 grit diamond stones, so it’s strop-ready. I’m curious to know if there would be a benefit to backing it off a little or just stropping normally.

I would guess that at a slightly shallower angle the tiny facet from the new profile would blend in better as well, but I haven’t toyed with much on my new kit yet 🙂

[Anthony Yan]

Hi Clay,

Nice!! 🙂

Just a couple of questions:
(1) Are these images from your new metallographic microscope?
(2) What is the scale of the images (if you know)?
(3) Are these photos taken as black-and-white?

Looking forward to more of your results. 😀

Sincerely,
–Lagrangian

[wickededge]

Interesting info on rounding the edge a little. Would it be advisable for some situations to back off the arms a degree or so if you wanted to maintain really sharp geometry? I’m playing with an old Imperial filet knife as I type this and just finished the 1000 grit diamond stones, so it’s strop-ready. I’m curious to know if there would be a benefit to backing it off a little or just stropping normally.

I would guess that at a slightly shallower angle the tiny facet from the new profile would blend in better as well, but I haven’t toyed with much on my new kit yet 🙂

One of the things that I found really interesting is that I still experienced rounding with stropping after lowering the angle by two degrees per side. I’ll try the experiment again at 3 degrees lower per side and so on until I find the setting that allows me to just reach the edge without rounding.

-Clay

[wickededge]

Howdy 🙂

Just a couple of questions:
(1) Are these images from your new metallographic microscope?
These are from the new scope. The 100x objective still isn’t working, so I’m limited to 800x.
(2) What is the scale of the images (if you know)?
What do you mean by scale? Are you talking about microns/pixel or something else? The camera is 10 MP.
(3) Are these photos taken as black-and-white?
These are taken in color.

So far, it’s a really fun study to do. I’m working on a developing a little jig that will allow me to hold the blade in exactly the same place on the stage so I don’t have to do so much fiddling for every picture.

-Clay

[Anthony Yan]

Hi Clay,

By “scale” I just mean a length-scale. For example, what is the length across the width of the image? Or something like a little line in the image with a measure of how long it is (something like 0.01mm, or 10 microns, etc.). Maybe you could take an image of your linear stage micrometer at the same magnification?

I’m kind of curious how big the scratches are.
Sincerely,
–Lagrangian

[wickededge]

No problem, I can do this.

Hi Clay,

By “scale” I just mean a length-scale. For example, what is the length across the width of the image? Or something like a little line in the image with a measure of how long it is (something like 0.01mm, or 10 microns, etc.). Maybe you could take an image of your linear stage micrometer at the same magnification?

I’m kind of curious how big the scratches are.
Sincerely,
–Lagrangian

-Clay

[Phil Pasteur]

Clay,
Just curious, what is the problem with the 100X objective? I have no experience with the kind of microscope that you have, but have spent lots of time with various lab microscopes. Usually changing an objective is relatively easy…

Phil

[wickededge]

I can’t tell what’s wrong with it except that I can’t get it to focus. I’ve sent it back once and the new or repaired one they sent back is the same. Their tech is looking into it now. Hopefully I’ll have an answer today.

Clay,
Just curious, what is the problem with the 100X objective? I have no experience with the kind of microscope that you have, but have spent lots of time with various lab microscopes. Usually changing an objective is relatively easy…

Phil

-Clay

[Phil Pasteur]

I hope you do get a GOOD answer. It would drive me slightly nuts to have something like that microscope and not be able to use it to the max extent of its capabilities (especially considering the price!!!).
Heck, I am impatient to see what it does… and I didn’t even pay for it
🙂

Good luck with it!
Phil

[John Sacchetti]

Clay, I hope you can find an ideal number of degrees to back off when moving to stropping with split bovine. I love how fast chromium oxide on split bovine can polish out all scratch marks, but it is so easy to round the edge. Once you work the paste or spray into the split bovine, those little fingers just polish away.

[Phil Pasteur]

Hi,
What kind of chromium oxide are you using?
I have a bunch of it and they all seem to have considerably different actual grit levels. It seems that some, as in from HA is rated at 0.5 microns nominal. I have some that is no name stuff that I have read is closer to 6 microns and contains more aluminum oxide than CrO… Typically the 0.5 micron CrO wouldn’t be a great scratch remover. Just wondering what you are using that does such a great job for you.

I know that you addressed Clay directly, but let me take a swing at this.

Most people say that 1 to 2 degrees more acute (lower) is a good place to start trying for stropping. I tend to use about a degree less for horse leather…and whisper light strokes. BTW, this is in general, I have never used CrO on WEPS paddles.

If you use more pressure, maybe try 1.5 or 2 degrees lower. I think there is no “ideal”… “it depends” (there is that equivocation again 🙂 ) on the materials that you use and your technique. Do some experimenting and see what works for you. I don’t think that Clay nor anyone else can determine that for you. The best you will get is some suggestions on where to start trying things.

Phil

[Geocyclist]

I use 1 degree. I think it depends entirely on your pressure. if you go very, very light strokes the maybe the same angle would work.

With the first strop I can tell in about 5 – 10 strokes how the angle is working. The polish is good enough to see if I am hitting alof the bevel.

[cbwx34]

Clay, I hope you can find an ideal number of degrees to back off when moving to stropping with split bovine. I love how fast chromium oxide on split bovine can polish out all scratch marks, but it is so easy to round the edge. Once you work the paste or spray into the split bovine, those little fingers just polish away.

If you’re talking about losing the “bite” of an edge, one thing you can try, is to add it back in. Clay has posted this somewhere (that I can’t find right now), but basically, after stropping, raise the angle a couple of degrees, and with your finest stone or ceramic, make a couple of passes. This will leave your polished edge, but return the bite.

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