Monday, August 08, 2016

Slowly Returning to the Shop

I still can't really do anything of substance in the shop but I did a little re-arranging of the sharpening bench and cabinet and the real biggie....Cleaned up and oiled the RV's wood sink cover/cutting board. Hey, it's a start.

The sharpening bench: On the left is set up for JNats and other waterstones and the right end for sandpaper and oil stones. The overhead cabinet holds the stones and most of the other "stuff" needed for sharpening.

This one is real excitement, the RV's sanded and oiled sink cover/cutting board.

And last, a chair MsBubba rescued and wanted me to "fix". After much butt scratching I decided to screw slats to the frame. One down, four to go.

As posted, it's a start.

Received an email from David Savage this morning posting about something I've long said: Shiny is not necessarily sharp.

Part of his email:

Ohhh! This is going to be bad.

You know more tosh has been written about sharpening woodworking tools than a grown man can tolerate. But I shall proceed, but only if you are sitting comfortably.

There is a convention that sharpness is the product of two polished surfaces brought together at a suitable angle usually somewhere between 25 degrees and 30 degrees. Pedants may disagree, but I do not give a hoot.

Polished surfaces are generated by using a course abrasive, then a a grade finer, then a grade finer. The objective of each stage being, to remove the scratches of the previous layer. O K, so a shine in this context would the objective, yes? The more scratches removed, the more polished and shinier the surface would become??? I have used a shiny surface to a chisel back or plane blade back as a sign that I have done a good job for years.

Apparently this is just not so. Look at the image below this is a surface created with an 8000 grit Japanese Water stone. this is the kind of polishing stone I and many other Western Woodies have been using for years. they are fast to cut relatively cheap and they give this great result.
So whats the problem? Well look at the second image below. This is the same tool polished with a NATURAL Japanese abrasive stone. The scratches are finer that is clear. What is confusing and counter intuitive is that the surface is NOT so shiny.
Tomohito-San who has been my guide on this has been trying to convince me that shiny is not automatically sharp and this is his proof. I have been using a couple of natural stones on plane blades for a while and can report a real difference in performance. They cost a lot more than man made water stones. My stone was about £300 and I only use it in specific situations where I need a surface from the Tool..."



  1. Surely though, neither image confirms which is actually more sharp. The comparison only confirms that the second stone smooths the scratches better? I might be missing the point though!

  2. I hope you're only using your good arm on the sink cover and the seat slats. I didn't figure you'd do any ww until after your several thousand mile odyssey across the country in the new RV.

  3. Matt,

    I've just used the right arm to stabilize things. I can't do much that way but move things around and even that is limited. You are correct, once back from the PNW I hope to get some function back. BTW, it is really hard not to go ahead and use it because for the most part it is doing ok.


  4. Gary,

    You are correct, from the two images you can not tell if either is sharp. If the images were at a higher magnification where you could see the difference at the cutting edge the JNat edge would be smoother just as it is in the two images. That smoother edge will be sharper and will stay sharp longer because there are not as many places for the edge to break down.

    BTW, part of the mirror shine from synthetic stones is from the slightly deeper and ordered scratch pattern. Natural stones tend to leave much more random and shallower scratches giving a hazy appearance instead of a mirror shine.


  5. Absolutf..inkly..
    I known its seems strange, but remember a few years ago Lee Valley start using a new machine to grind the back of their blade wicked flat, and the resulting surface it left is a dull grey not shiny, but very very flat...
    At the time it left me scratching my butt cheeks, but it make sense

    Bob and Rudy drinking our morning coffee

  6. Bob,

    Yep I even "polished" a few of those backs with waterstones. They polished up real pretty but when you looked at the polished back under magnification it had ordered deep scratches instead of a smooth matt surface. Those very small, ordered scratches are part of what makes the "shine". My training as an economist steps up, Ceteris paribus, hazy will leave a sharper and longer lasting edge.

    Just 5 more days of the critters and I living without adult supervision. Then a couple or three days later we head to the PNW. BTW, I'm ready for some cool, saw just under 110F on the truck thermometer while out running the streets yesterday.

    Off to get my first cup of coffee and treats for the hairy ones.