Page 1 of 2 12 LastLast
Results 1 to 10 of 11
Like Tree12Likes

Thread: Scratches when using DMT 325 as lapping stone

  1. #1
    Member
    Join Date
    Mar 2017
    Location
    Cincinnati
    Posts
    74
    Thanked: 4

    Default Scratches when using DMT 325 as lapping stone

    At the advice of a very well respected source, I ordered a DMT 325 to lap my shapton 16K. It arrived a few days ago, and today (well, yesterday, technically) was the first time I cad a chance to actually use it. It certainly seemed to lap just fine, but it left a bunch of scratches and gouges in the Shapton, a couple of them deep enough to feel with the edge of my fingernail; I can't imagine that to be good for honing. Has anyone else had a similar experience? Am I doing something wrong?

    Here are some picks, I rubbed pencil graphite over the scratches to make them more visible:Name:  IMG_0399.jpg
Views: 229
Size:  10.9 KB

    Name:  IMG_0398.jpg
Views: 251
Size:  19.3 KB
    Last edited by FoliageFace; 05-26-2017 at 04:21 AM. Reason: Clarification of subject

  2. #2
    Senior Member blabbermouth Speedster's Avatar
    Join Date
    Jan 2012
    Location
    Spokane WA
    Posts
    2,935
    Thanked: 704

    Default

    Before using a DMT325 to lap any hone, you should take a large screwdriver shank and run it vigorously across the plate to knock down any loose diamond bits. Once I did this procedure, I had no issues lapping my Naniwa Super Stones. However, I did run into some scratch issues a few weeks ago and had to redo this procedure again.

    Too bad the Shapton DGLP costs nearly $400, but that is the lapping plate I would use if I had the coin for Shaptons.
    --Mark

  3. The Following User Says Thank You to Speedster For This Useful Post:

    FoliageFace (05-26-2017)

  4. #3
    Member
    Join Date
    Mar 2017
    Location
    Cincinnati
    Posts
    74
    Thanked: 4

    Default

    That is super helpful, thank you!

  5. #4
    Senior Member dinnermint's Avatar
    Join Date
    Jan 2012
    Location
    Waukesha, Wisconsin
    Posts
    1,943
    Thanked: 390

    Default

    I have abused the hell out of my dmt and there's stil one dang diamond scratching my hones.

    Doesn't affect the edge, a good phrase I stole from someone; "Think of it as negative honing space, it's below the surface where the blade is riding."

  6. #5
    Moderator rolodave's Avatar
    Join Date
    Aug 2011
    Location
    Racine, WI USA
    Posts
    7,530
    Thanked: 1927
    Blog Entries
    1

    Default

    If the screw driver does not work use some smooth concrete like in a basement.
    dinnermint likes this.
    If you don't care where you are, you are not lost.

  7. #6
    Senior Member blabbermouth
    Join Date
    Dec 2014
    Location
    Virginia, USA
    Posts
    2,224
    Thanked: 481

    Default

    Screw driver shank, hone a chisel or something similarly hard. Lapping a hard natural a bit can help too.

    I was never happy with the scratches left behind by the DMT though. I know it's supposed to just be 'negative space' and not effect how they hone, but it bugs me all the same. So I typically wind up chasing the DMT with sand paper up to 1 or 2K depending on the stone, and I use my Naniwa red brick to refresh the honing surface when it gets clogged with swarf. No scratches, I'm a much happier camper.
    Addison likes this.

  8. #7
    Senior Member dinnermint's Avatar
    Join Date
    Jan 2012
    Location
    Waukesha, Wisconsin
    Posts
    1,943
    Thanked: 390

    Default

    Quote Originally Posted by Marshal View Post
    Screw driver shank, hone a chisel or something similarly hard. Lapping a hard natural a bit can help too.

    I was never happy with the scratches left behind by the DMT though. I know it's supposed to just be 'negative space' and not effect how they hone, but it bugs me all the same. So I typically wind up chasing the DMT with sand paper up to 1 or 2K depending on the stone, and I use my Naniwa red brick to refresh the honing surface when it gets clogged with swarf. No scratches, I'm a much happier camper.
    I agree, as far as my naturals are concerned, particularly the slow and harder ones, need all the space I can get. Coticules just look better with a nice smooth surface, plus gouging out garnets gives me the willies

    For synthetics, it bothers me a little, but i try to ignore it in favor of laziness
    rolodave and Marshal like this.

  9. #8
    Senior Member rodb's Avatar
    Join Date
    Apr 2008
    Location
    Saint Paul, Minnesota, United States
    Posts
    2,943
    Thanked: 433

    Default

    I usually use my well used 850 Smiths diamond hone after the 320 to take out the scratches, 1000 grit wet/dry on a hard surface would probably work as well

  10. #9
    Member
    Join Date
    Mar 2017
    Location
    Cincinnati
    Posts
    74
    Thanked: 4

    Default

    Thanks for all the suggestions! I sharpened on of my "rough work" knives on the DMT, then hit the Shapton again, and the result were much improved. I also adjusted the lapping technique a bit, favoring a very small lapping movement, and just letting the weight of the Shapton rest on the DMT, rather than pressing at all, which I think helped. It's a lot less aggressive, and probably will take a lot longer when I'm doing an actual flattening, but I guess that's the price I pay for getting a $50 not-really-a-lapping-plate rather than popping $400 for the actual Shapton plate. I can live with that.
    dinnermint likes this.

  11. #10
    Senior Member blabbermouth
    Join Date
    Apr 2012
    Location
    Diamond Bar, CA
    Posts
    6,553
    Thanked: 3215

    Default

    “but I guess that's the price I pay for getting a $50 not-really-a-lapping-plate rather than popping $400 for the actual Shapton plate. I can live with that.”


    No, you don’t need a $400 plate to lap a stone, most any flat diamond plate will work.

    They all, even Atoma’s can use some smoothing out, sharpen a couple of knives, or bevel the edges of a stone or two to knock off any high diamonds, usually the edges.

    I would not worry about your stone it will flatten out with time and refreshing. You can finish lap them with other lower grit stones.
    Geezer and Marshal like this.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •