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Ascending Stone Progression at 800x

Recent Forums Main Forum Techniques and Sharpening Strategies Abrasives Ascending Stone Progression at 800x

Viewing 15 posts - 16 through 30 (of 31 total)
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  • #4738
    Mathew Whaley
    Participant
    • Topics: 1
    • Replies: 22

    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.

    #4740
    wickededge
    Keymaster
    • Topics: 123
    • Replies: 2938

    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

    #4752
    Tom Whittington
    Participant
    • Topics: 4
    • Replies: 159

    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 🙂

    #4760
    Anthony Yan
    Participant
    • Topics: 4
    • Replies: 96

    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

    #4762
    wickededge
    Keymaster
    • Topics: 123
    • Replies: 2938

    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

    #4763
    wickededge
    Keymaster
    • Topics: 123
    • Replies: 2938

    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

    #4767
    Anthony Yan
    Participant
    • Topics: 4
    • Replies: 96

    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

    #4773
    wickededge
    Keymaster
    • Topics: 123
    • Replies: 2938

    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

    #4792
    Phil Pasteur
    Participant
    • Topics: 10
    • Replies: 944

    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

    #4794
    wickededge
    Keymaster
    • Topics: 123
    • Replies: 2938

    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

    #4800
    Phil Pasteur
    Participant
    • Topics: 10
    • Replies: 944

    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

    #9109
    John Sacchetti
    Participant
    • Topics: 2
    • Replies: 5

    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.

    #9113
    Phil Pasteur
    Participant
    • Topics: 10
    • Replies: 944

    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

    #9114
    Geocyclist
    Participant
    • Topics: 25
    • Replies: 524

    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.

    #9122
    cbwx34
    Participant
    • Topics: 57
    • Replies: 1505

    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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