wickededge wrote:

The stock progression is definitely next. For the microscope positioning, I leave the scope in the stand. Then I tape photo paper to the bottom of the stand to add some extra light via reflection. I trace the knife's outline on the paper so I can get it back in the same position every time.

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I'm also having difficulty getting the scope back to the exact same position on the blade.
Clay, help.

holymolar wrote:


I'm sorry I forgot to shoot that picture today! The setup goes like this:

I tape some photo paper to the base of the microscope stand. Then I lay the knife down on its side, in a way that it rests naturally, bumping some portion of the knife up against the edge of the stand so that there is a natural stop in the heal-to-tip dimension. If adjust the knife side to side until I find the bevel in the scope and micro-adjust until it's just where I want it. At that point I take a fine line pen and trace the outline of the knife as accurately as possible. I then tighten down all the adjustments on the scope stand so it doesn't move. With that set up, I can take the knife out, sharpen it, put it back in the same spot. I just bump the knife back up to the edge of the stand, align the edges with the pen marks and it's good to go.

I hope that helps explain it a little better.

I get it now..
I thought that the stand you were talking about was the WE clamp.
It is the base of the scope stand that you posted a picture of earlier.
I can see what you are talking about now. Not having that same stand, right now anyway, means that I can't duplicate that method. I have been trying to use the scope on the knife blade still mounted in the WE clamp.

I am not as good at this as you (obviously), or at least haven't yet figured it out, but I am not confident that I can get the blade back in the clamp precisely time after time. Especially with knives with a curved or sloped spine (Spyderco) it seems that there is room for error because of rocking on the depth gauge and my imprecision at getting the knife back in clamp in the same exact place between the pivot and tip, using the length gauge. This, of course will introduce errors in the way the stones hit the blade..
or so I believe.

Thanks for the explanation!

Phil

Thanks Clay,
I, too, was trying to use the scope while the knife was still in the WE vise - which just isn't practical. Taking the knife out of the WE vise and placing it on the base of the scope stand is the only way that I can think of to do this.

Here are before and after photos using my smaller scope stand to mark the position of the knife blade on paper, etc. I tried it several times and it worked.

When returning the knife to the scope stand after sharpening, if I wasn't exactly on the same spot on the blade, I was < 1 mm off. So it was easy enough to slightly move the blade to find the spot - as long as I had a landmark on the blade (such as a deep cut or something) to look for.


Drawing the blade outline with a lead pencil onto a post-it note stuck to the base of the scope stand


After removing the blade and showing the lead pencil outline of the blade

That looks perfect. Thank you for capturing and sharing it. Your edge has a nice gleam to it!

Clay, the samples are on the way

---
Ken


wickededge wrote:

Got my Dino in!!! Will be posting pics soon of diff. grit strops on split grain (rough side out) cow hide leather strops...

razoredgeknives wrote:


Please do! Really interested!

This threat has become the host of many topics, but I would like to return to the initial question posed by Josh and the pictures posted by Tom. Tom's pictures clearly showed that, although the WE diamond stropping pastes on leather strops did result in a very nice edge, the stropping pastes were much less abrasive than stones with diamond particles of comparable (micron) sizes; the stropping pastes produced only tiny scratches that were much smaller in size than the stones do.

I set out to see whether I could reproduce the results by Tom. I also wanted to test the hypothesis that the compounds on leather were not so abrasive because the diamond particles got hidden in the "valleys" of the leather (since leather is quite textured). To do so, I also stropped with the diamond pastes on balsa: diamond particles of 14 micron (or 3.5 micron, for that matter) cannot hide in the spaces between the filaments of the balsa.

I sharpened a knife up to 1000 grit with stones (and later 1600 grit) and then did 500 stropping strokes with 14 micron paste and 10 micron paste, both on leather and on balse. I took photographs at 50, 100, 250 and 500 stropping strokes. And I got sometimes very polished edges...



In fact, I did every experiment twice (with consistent results), since a new microscope stand came in with which I could make much better pictures when I was nearly done with the stropping.

You can find the complete story on my blog.

But for those in for quick conclusions:

• I was able to reproduce Tom's results. The 14 micron and 10 micron diamond pastes produce scratches that are much smaller than one would expect on the basis of the grit comparison chart.
• This is not due to the diamond particles hiding in the leather. We see exactly the same tiny scratches when using these compounds on balsa.

So the mystery remains. How come these pastes are so little abrasive compared to the equivalent stones?

I would like to throw in a second mystery. As the above picture shows, the pastes are effective. How can pastes with so little abrasive power be so effectie?

mark76 wrote:


I can't see your pictures, but love the write up. A next study step would be to go from the 1000 grit to plain leather w/ no compound to examine the burnishing effect. That way you could tell how much of what you're seeing is the abrasive and how much is the substrate. My theory is that the burnishing effect of the leather is significant and is greatly improved by the added 'stiction' that the paste provides. Ideally, it would great to test an abrasive free paste on the leather. That sounds like a very fun experiment. I think the reason the diamonds are making such little scratches is two-fold - 1) The diamonds press equally into the leather as they do to the metal so you're not getting a full value scratch 2) The numbers of diamonds on the strop may be significantly less than those on the stones.