First test of a cheap, Chinese sourced natural stone- guardedly optimistic...

Discussion in 'Sharpening Station' started by Bert2368, Mar 17, 2019.

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  1. May 10, 2019 #61

    Michi

    Michi

    Michi

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    I picked up one of those XXL stones, too. Out of the box, the stone was smooth and flat on one side, and it had a few minor surface undulations and cutting marks on the other side. A few minutes with an Atoma 120 and 400 got both sides very smooth.

    The edges of the stone were very sharp, so I chamfered them a bit. The two sides of the stone are almost, but not quite, parallel, maybe 1º off. (Not that this would matter.) The strata runs parallel to the cutting surface on mine. It looks and feels a lot like fine slate. I don't think it is slate though—the texture of the grain is finer than any slate I've seen.

    Not surprisingly, the stone doesn't absorb any water. It's splash and go all the way.

    So far, with that stone, I've sharpened only two Opinel Carbone knives that were quite blunt and needed a touch-up. Normally, I'd just use a 3000 stone for that, but decided to try them on this one instead.

    In short, my stone is hard, slow, and fine. I'd say it's in the 6000–8000 grit range. Definitely finer than my Rika 5000. Slow to raise a slurry. I helped it along a little with the Atoma 400. I got a good edge on those Opinels, but it took a fair bit longer than touching up on a Cerax 3000 or Rika 5000. The finish on the edge is not quite a mirror; it leaves a slight haze.

    This is a hard stone. I think it'll take me years (probably more than my remaining life span) before it will need flattening.

    Overall, I think this is a good finishing stone, especially at the price. It'll also work for touching up (soft-ish) steels if you are in a hurry and don't want to wait ten minutes for a soaking stone to be ready. (You'll spend a bit more time sharpening, but you'll gain more than that by not having to wait for the soaking stone to be ready.)

    And this stone will probably outlast three generations of sharpeners. Good value for money!
     
  2. May 10, 2019 #62

    stringer

    stringer

    stringer

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    Here's a pic of the scratch pattern. Fine feather scratches. I would call it bright but hazy.

    IMG_20190510_073710.jpg

    Here is the pattern for shapton glass 8k for comparison

    IMG_20190510_073721.jpg
     
  3. May 14, 2019 #63

    Bert2368

    Bert2368

    Bert2368

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    I have re sharpened the new CarboNext sujihiki, finishing it on the big brick from Etsy. Just for fun, I sharpened a couple of the (real-ish) D2 Chinese pocket knives first on an (allegedly) 3,000 grit Chinese diamond waterstone then de burred with a natural cork before finishing on the big brick, all were very briefly stropped on denim with a bit of "Flitz" metal polish.

    20190514_122441.jpg

    Outstanding results, among the best outcomes I have had with semi stainless or stainless steels.

    I have started using the denim stropping material over a thin layer of a quite firm closed cell foam plastic which is normally used to make the cores of broadhead archery targets, the two layers supported by a piece of heavy "float plate" glass.

    This layering with this foam gives more compressability and "spring" to the denim surface, stropping can then be done with a flat ground/scandi ground blade with the barest of secondary bevels laid flat on the denim, it becomes easy to keep the optimum angle. All I do to tune effect is vary pressure, very light pressure with minimal number of passes seem to work best for me, given a well de burred and freshly sharpened edge from "the big brick".

    The science of sharp site owner makes the point on one of his pages that much of the effect of strops is dictated by firmness/springyness of the surface bouncing back from compressed state as the edge is drawn over it. I'm trying to "tune" this, inital results suggest it works.

    If anyone wants some of this foam to experiment with, I have several bales of it. Makes a good packing material for stones sent in the mail too. I needed to blow up targets for a TV commercial and they were too tough to blow up with their guts still inside-

    My day job is rather odd sometimes... Spend a day disemboweling archery targets and re-filling them with pre fragmented theatrical debris (coarse bark mulch + peat moss) and explosives? Check...



     
    Last edited: May 14, 2019
  4. May 15, 2019 #64

    Bolek

    Bolek

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    What do yo think about the "(allegedly) 3,000 grit Chinese diamond waterstone".
    BTW the big brick from Etsy is on the way.
     
  5. May 15, 2019 #65

    Bert2368

    Bert2368

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  6. May 15, 2019 #66

    Bolek

    Bolek

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    Thanks.
    Is it wear resistant , as it looks beeng 1 to 2mm thick only ?
    It certainly cuts steel effectively & fairly quickly comparing it to Shapton 2,000 to Shapton glass 500 or to an actuel 3000 stone ?
    Have you tried the finer ones (#6000 or #12 000) ?
     
  7. May 15, 2019 #67

    Bert2368

    Bert2368

    Bert2368

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    Comes with a small stone for flattening or removing glaze/stuck on steel. Does NOT wear fast. Have needed to remove steel buildup 2X so far.

    Cuts faster than my green Shapton 2,000. I don't have the Shapton 3,000 water stone or any 1,000 Japanese (non diamond) water stones at all to compare.

    I do have the 1,000 diamond water stone as well, would like to go back and get the 6,000.

    Found them through a reference on a Euro knife site.
     
    Last edited: May 15, 2019

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