Results 1 to 13 of 13

Thread: The Dreaded Stone Contamination

  1. #1
    Join Date
    Apr 2010
    Location
    Tokyo, Japan
    Posts
    1,550

    The Dreaded Stone Contamination

    Konobu finished up my order of kiridashi and marking knives last week, so I jumped on my little bicycle and peddled over to his forge to pick them up yesterday. He did a beautiful job!

    Due to health problems, it took two years for Konobu to complete this order, but I have high hopes his recovery is now complete, so long as he doesn't overdo it.

    I spent several hours sharpening and evaluating the kiridashi and experienced something that, judging from the content of some of the posts I have seen on SC, I think some of you may have experienced too.

    My typical grit progress when sharpening a brand new blade in the shop is 300, 1000, 2000, and 6000 grit waterstone, and then finishing off with either a 10,000 grit manmade stone or natural stone of undefined grit. I abbreviate this process, however, for simple resharpening, or when on the jobsite.

    As I worked the blade on the 6,000 grit stone, some deep scratches remained that I wasn't able to remove. It was like the 6,000 grit stone actually made things worse instead of better. When I next worked the blade on the natural stone, new deep scratches appeared. Yikes!

    Fortunately, I knew the cause and took action. What had happened is that somehow I had contaminated one or more of my stones with the grit from a rougher stone, and that grit had become embedded in the surface of the next stone. This can easily happen especially when flattening stones, which was the last operation I had done before putting these stones away after my previous sharpening session.

    To fix this, I put each stone under running water and scrubbed all 6 surfaces briskly with a stiff bristle brush and soap. I used an oblong-shaped natural sisal brush called a kamenoko or "baby turtle" brush available throughout Japan. Then I used a tsushima nagura stone under running water to scrub each stone's face thereby removing a tiny bit of each stone's surface, along with any contaminants. This solved the problem.

    Sharpening stone contamination can come from any number of sources. Dirty water with suspended grit particles is the most popular method, as is grit from the previous stone remaining on the blade being sharpened, and being inadvertently transferred to the next stone. And don't forget contaminants in airborne dust and dirt that land on your stone's face without the control tower's permission. Sword sharpeners, for whom the beauty created by the sharpening stone is so important, are famous for waiting to sharpen the blades of customers that want the ultimate polish until the rainy season, when airborne dust is at its annual minimum.

    Anyway, if you find that your stones are no longer producing the polish you expected, I suggest you take the time to clean and decontaminate your stones. Oh yea, and don't forget to use clean, fresh water to wet your stones, wash your blades before moving onto the next stone, and wrap your stones in newspaper to keep dust off them when you are not using them. Sharpening stones have feelings too.

    All is well.

    Stan
    Last edited by Stanley Covington; 10-16-2016 at 6:09 AM.

  2. #2
    Where are the photos!

  3. #3
    A good reminder Stan.

    But hey, you forgot to tell us - did the kiridashi and marking knives perform as well as you expected them to? I mean, you waited 2 years so we're kind of hanging on, waiting to hear and maybe even see a few pics of Konobu's work.

    Fred
    "All that is necessary for the triumph of evil is that good men do nothing."

    “If you want to know what a man's like, take a good look at how he treats his inferiors, not his equals.”

  4. #4
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,252
    Blog Entries
    7
    Stan, this post is timely, I spent Friday afternoon diagnosing this issue and fixing it. I like looking at my Japanese stones, but I think I will build wooden covers for them.

    The downside, of course, to not having a sink in my shop is that this kind of thing can creep up over time without really noticing. So, I will probably also make the stone cleaning a ritual.
    Bumbling forward into the unknown.

  5. #5
    Join Date
    Apr 2010
    Location
    Tokyo, Japan
    Posts
    1,550
    Quote Originally Posted by Trevor Goodwin View Post
    Where are the photos!
    Trevor:

    The photos will be part of different post.

    Stan

  6. #6
    Join Date
    Apr 2010
    Location
    Tokyo, Japan
    Posts
    1,550
    Quote Originally Posted by Frederick Skelly View Post
    A good reminder Stan.

    But hey, you forgot to tell us - did the kiridashi and marking knives perform as well as you expected them to? I mean, you waited 2 years so we're kind of hanging on, waiting to hear and maybe even see a few pics of Konobu's work.

    Fred
    We went through a long design process, but I have been using a final, approved prototype for a year and half now, and just need to confirm that the "production run" (ha ha) of ten knives matches the quality of the prototype. It is great knife, certainly the best I have ever used, and I have tried knives from a lot of blacksmiths.

    I need to do some cutting and chipping, and resharpening, but knowing Konobu's work, I am confident in the quality. Specification, fabrication, verification. How do you say that in Latin?

    I will make another post with pics of the knives, Konobu's forge and smiling face (he's a cutie), and the results of my tests.

    Stan

  7. #7
    Join Date
    Apr 2010
    Location
    Tokyo, Japan
    Posts
    1,550
    Quote Originally Posted by Brian Holcombe View Post
    Stan, this post is timely, I spent Friday afternoon diagnosing this issue and fixing it. I like looking at my Japanese stones, but I think I will build wooden covers for them.

    The downside, of course, to not having a sink in my shop is that this kind of thing can creep up over time without really noticing. So, I will probably also make the stone cleaning a ritual.
    Different people have different opinions/methods about how to store stones. I keep my manmade stones in a bucket of water year round. I add some poison to the water to keep the crud and mosquitoes from turning the bucket into a public swimming pool, and put a piece of roofing membrane over the bucket as a lid to keep dust out and the water in. The water of course carries grit from all those stones, so I wash the stones before using them. I guess I didn't do a good job this time.

    Some people say you must clean all the mud off a natural stone after every use, and store them in a pristine state like sleeping beauty. I did this for a time, but changed my mind. I realized that the mud cannot possibly do the stone any harm. It is the same stone after all, and quickly dries. But leaving it on the stone to dry provides a layer of protection that at least partially prevents dust from falling directly on the stone. When I wash the stone before use, any dust is carried away with the mud.

    I don't like storing my stones in boxes because I use water as a lubricant for all my stones, and one cannot store a stone in a closed box until it is completely dry, something that can take days in the case of a waterstone. Instead, I simply wrap my stones in newspaper and store them under my bench. The fresh newspaper cushions, keeps clean, and dries the stone without the risk of growing mold or mildew. Cheap too.

    Newspaper is a wonderful product. Although you wouldn't think so, it prevents rust too, don't you know. I just wish the world's scribblers would find a better use for it than printing falsehoods, defamation, empty conjecture, and misleading exaggerations. Too many people believe them.

    Brian, give a stiff brush a try. It really helps.

    Stan
    Last edited by Stanley Covington; 10-16-2016 at 9:27 AM.

  8. #8
    Join Date
    Jan 2009
    Location
    Williamsburg,Va.
    Posts
    12,402
    i have a shelf where I store my stones. It has a low,overhanging shelf above it so it keeps dust from settling from above. It is in a part of the shop where there is hardly any air movement. The stones have plastic boxes which they are put into also,before they go on the shelf.

    Of course,my stones are entirely different from yours.(Spyderco ceramics)

    It must be nice having small blacksmith's shops near you where you can get things made. I have my own blacksmithing corner in my shop,though I do not consider myself a blacksmith,or hammer man in general! I can go to Williamsburg,of course,but am limited as they are open to the public,and only will make 18th. C. things. My friend Jon is an excellent blacksmith,too. We made a good team because we both had skills that did not overlap too much with the other person's. And,we tended to like to do the jobs that the other person didn't much care for. Jon liked to weld iron wagon tires for the coaches in the museum,for example. I would not like to do that at all! I never liked welding!!
    Last edited by george wilson; 10-16-2016 at 10:13 AM.

  9. #9
    Join Date
    Apr 2010
    Location
    Tokyo, Japan
    Posts
    1,550
    Quote Originally Posted by george wilson View Post
    It must be nice having small blacksmith's shops near you where you can get things made. I have my own blacksmithing corner in my shop,though I do not consider myself a blacksmith,or hammer man in general! I can go to Williamsburg,of course,but am limited as they are open to the public,and only will make 18th. C. things. My friend Jon is an excellent blacksmith,too. We made a good team because we both had skills that did not overlap too much with the other person's. And,we tended to like to do the jobs that the other person didn't much care for. Jon liked to weld iron wagon tires for the coaches in the museum,for example. I would not like to do that at all! I never liked welding!!
    I love blacksmiths. Elemental magicians and the most important trade to human civilization.

  10. #10
    Join Date
    Sep 2007
    Location
    Longview WA
    Posts
    27,347
    Blog Entries
    1
    Newspaper is a wonderful product. Although you wouldn't think so, it prevents rust too, don't you know.
    My experience with newspaper and rust is quite different. The newspaper (American may be different than Japanese) seemed to absorb moisture which found its way to the item inside.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  11. #11
    What are your all's thoughts about contaminating waterstones during the flattening process? I typically flatten my whole batch of stones all at once, using an Atoma plate. I rinse the Atoma in a bucket before proceeding to the next one, and have decided not to worry about the possibilities of contamination. Is this kind of cross-contamination likely to produce the results that OP is talking about?

  12. #12
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,252
    Blog Entries
    7
    Thanks Stan, that is a good idea to leave the mud and let that carry away any dust before the next use. I'll also give the stiff brush a try, I have one in mind with strong bristles.
    Bumbling forward into the unknown.

  13. Flatten in sequence from finest to coarsest. That way the contamination won't be a problem



    Quote Originally Posted by John Crawford View Post
    What are your all's thoughts about contaminating waterstones during the flattening process? I typically flatten my whole batch of stones all at once, using an Atoma plate. I rinse the Atoma in a bucket before proceeding to the next one, and have decided not to worry about the possibilities of contamination. Is this kind of cross-contamination likely to produce the results that OP is talking about?

Posting Permissions

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