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sharpening stone - seen better days

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  • sharpening stone - seen better days

    I've got a really nice sharpening stone.

    (bet you don't hear that often).

    by nice I mean I like it, think its a Norton.. AO.. gray on one side, orange on the back.
    Odd ball size, though, picked it up as NOS in a second hand store many moons ago.
    .. its about 3" x 5" x 1"

    Was brand new.

    Anyway it's usually gotten a lot of use but is throughly gunked up now. Tried all the
    old tricks: kerosene, wire brush, soaking in soapy water -- to no avail.

    I even gave it a run over my DMT rough diamond plate thinking I could cut into it but
    I didnt' have the heart to put the DMT through that and gave up quickly.

    It'll clean up a little but the surfaces appear glazed / dull.

    Any secret weapons out there?

    I tried putting in on the surface grinder but the mag chuck wont' hold it.

    that was a joke. (but its so full i bet the mag actually would! )

  • #2
    A silicon carbide dressing stone will quickly clean and flatten your stone They come in different styles and sizes, but here is one:



    • #3
      I do mine on the surface grinder. Use a precision screwless vise with a parallel under each end. I also use a large coarse plated diamond sharpener for smaller stones.
      Kansas City area


      • #4
        What Toolguy said. Take time and get the stone secured flat and "level" so you get a rectangle as the result and not a trapezoid.


        • #5
          On the surface grinder?


          Do I need a special diamond wheel?


          • #6
            No - a diamond wheel would load up and be useless in a flash. Use the same coarse grit AO or Ceramic wheel you would use for tool steel. A 46 grit works good, I don't go finer than 60 grit for that job.
            Kansas City area


            • #7
              As Toolguy said, the surface grinder with a diamond wheel is the best way to flatten your stone.

              RWO also has a good method to condition the surfaces.

              You can also buy some silicon carbide powder. Sprinkle some on a flat milled piece of cast iron and "lap" the stone. It will come out slightly convex but that's to your advantage. Renew the powder as needed while lapping.




              • #8
                I see that Toolguy rejects the diamond wheel approach.

                A 100 grit resinoid bonded/nickel coated wheel works well but must be "unloaded" with a dressing stick frequently.

                Each of us have had different experiences depending on when and where we worked. We can all share this knowledge.



                • #9
                  Try cleaning it on a concrete slab or sidewalk - preferably with some texture. That will scrub down most stones in short order.


                  • #10
                    I prefer the sidewalk method. I also put on the concrete used grinding grit from a surface grinder. Move stone in a figure 8 pattern and rotate 90 Degrees after every 8 or 10 cycles. .Finish on a new section of concrete so the stone doesn't wear convex.


                    • #11
                      I last used a big belt sander or linisher resurfaced flat in a couple of seconds, 80 grit cloth belt al ox norton i think


                      • #12
                        worked a charm

                        Granted, pucker factor wasn't too high but at least a 3.

                        Here is a before picture. Might not look too bad but it was barely cutting anymore.

                        I didn't completely flatten it out but was surprised at how well the wheel held up.
                        Was expecting worse. Like wearing out a $40 wheel for a $10 stone.

                        Quick dress between passes with a dressing stick. 3-4 passes
                        maybe.. ~0.002" per pass didn't seem to be a problem

                        then a lick on the coarse DMT:

                        Found a hard spot -- or something -- you can see it right at 12 o'clock in the last image, and
                        then the nearest corner is a bit low but I'm not sweating it.


                        • #13
                          Good job! If I may make a suggestion for next time, I would put a block on the side as well. You may want to run over the other side to get it fairly parallel while this side is flat. That can eliminate rocking or resonance.
                          Kansas City area


                          • #14
                            In my professional career we kept our stones flat by using a solvent (you pick) and rubbing 2 stones together. They will actually dress each other as it cleans them. Doing this at regular short intervals keeps them from needing more drastic measures. I had an arbor made with a diamond dressing point the went on the surface grinder. The stone was held in a vise and faced off with this tool. This was used for stones seriously out of flat.


                            • #15
                              hd: yes this particular stone was a bit neglected for too long.

                              can you describe your diamond arbor? curiosity more than anything else.. where you using the
                              point as a fly cutter?!