Thread: Learning Jnats with Microscope

Originally Posted by Euclid440

Because it was not honed with tape originally, we can see a demarcation near the middle of the bevel where much of the deep stria was removed on the front half, by the Tsushima slurry, and where much of the stria is visible on the back half of the bevel where the tape lifted the bevel off the stone fully.

Your final bevel looks a bit scratchy on the back side, but the front half is smoother, and the edge looks straight. There may be room for refinement with a finer nagura.



Edge impact damage goes much deeper than the edge, can easily go to a depth of half the bevel width and travels radially from the impact point.

So, even if you were to remove all the edge to the bottom of the chip, the damage can resurface as micro chipping after a few shaves and stropping.

For that reason, I would have removed all the edge, to at least the bottom of the chip on a diamond plate. A full progression honing would remove more of the edge, to more solid steel.

I didn't use tape on the frameback. So, as I tend to use torque pressure (in order to mantain bevel as narrow as it's possible) when honing, maybe the bevel aspect can be due to this.
I know the Red Ohira nagura isn't too fine, but gave me previous good shaves during the comparative tests I made, so I wanted to experience it on a different kind of blade.


You're right Euclid, but I wanted first to try smoothing the chip and see how it goes. I shaved with chips worst than this final one and had no problems. After a few shave I'll check the edge with microscope and see if damage resurfaced. Eventually, I will be able to make a new bevel if necessary, but this is an irreversible process and, since the blade is quite small (about 15mm) I preferred to go step by step before implementing operations that lead to a significant lowering of it. To do this if necessary, there is always time.

Originally the goal of this post was to experiment and test different nagura with your assortment of base stones and better understand what to look for to improve your edges. You have done that well and documented the process. Many new honers will be able to compare your excellent micrographs to their bevels at the various stages of Jnat honing progression.

Time for a more advanced but simple technique that produces stellar Jnat edges. Much of this technique is a modified version of Alex Gilmore’s, to simplify and produce great, repeatable results.

Start with a razor in good condition, chip-free, preferably with a solid edge no chips a fully set bevel. Tape the spine with 2 layers of electrical tape and one of Kapton. Take a picture of the starting bevel and edge.

Set an 8k bevel
Lap your 8k clean, bevel or round the edges with a diamond plate. The grit does not matter much, I use a 400 Atoma, but any medium to fine plate will work.

Wash the 8k clean of any slurry and flood the stone with water. Do a set of Ax Method half laps, 20,10,5,2, &1. Look at the edge and ensure that you are honing to the edge, from heel to toe. Use a “modified half lap”, X stroke. So, the toe starts at a corner and ends in the middle of the stone at the other end, in a shallow arc. Not just a straight up and down half lap stroke.
Use moderate pressure on the edge leading stroke, weight of the blade or lift the edge off the stone on the return stroke. Take a picture, Note edge improvement.

You may not be honing the full bevel, but it does not matter, the 2 layers of tape will ensure you are honing to the edge. We will hone the bevel fully by the end of the process. A modified X stoke half lap will shift the pressure to better hone the bevel from heel to toe.

Inspect the bevel and ensure you are honing to the edge from heel to toe. If needed, do another set of 10,5,2 &1 or X laps to hone problem areas and lay down an even 8k stria pattern. Take a Picture.

Once you have an even 8k stria pattern from heel to toe, strop the razor on linen 20 laps.

Remove 8k bevel with Jnat Diamond Slurry
Take your best Jnat, do a quick lap to smooth the stone face and round or bevel the edges. Raise a thickish slurry, thinner than cream but thicker than whole milk. Thickness is not critical. Add water to make a slurry puddle and keep the stone wet.

Once you have removed all the 8k we start to refine the edge. Do set of Ax laps, 10,5,3,2,1, use moderate pressure. Remove all the 8k stria. Look at the bevels, ensure all the 8k stria is removed especially at the edge, do X laps if needed. Use a finger to add a bit of pressure over problem areas with X strokes to remove all 8k stria.

First Dilution of Diamond Slurry
Add water to the slurry to make a puddle but not so much it runs off. Take the tips of your fingers and run them on the face of the stone from end to end to evenly spread the slurry across the face. Take a damp sponge and wipe off the bottom half of the slurry. You just diluted the slurry by half.

Add water to the wiped half and a bit more to the slurry. Do 2-3 light X laps to mix the slurry and dilute. Now do 10-20 X laps with lighter, but not weight of the blade pressure. Look at bevel and the edge. Ensure that the edge is getting straighter, and the finish is more refined. Do extra laps for problem areas. Take a picture.

Second Dilution of Diamond Slurry
Add water to the slurry, again spread the slurry across the stone with your fingers and wipe off the bottom half of the slurry to dilute by half again. Do another set of 10-15 light, X laps. Take a picture.

Nagura Finish Slurry
Strop the razor on linen 20 laps. Wash the stone with a sponge and running water. Take your favorite, finest Nagura and on a wet stone face make a very lite slurry, thinner than skim milk. Do another 10-15 slow, X laps, with lite weight of the blade pressure. Take a picture.

Dilution of Nagura Finish Slurry
Add water to the slurry and spread the slurry across the whole stone, wipe off half the slurry with a damp sponge. Add water and do 2-3 lite, X laps to mix the slurry. Do 10 slow, weight of the blade X laps. Take a picture.

Strop the razor on linen 20 laps. Add water and mix and spread the slurry on the stone. Wipe off half the slurry again, add water and do 4-6 slow weight of the blade laps.

Strop 20 laps on linen and 10 on leather and test shave.

It is a simple Diamond slurry dilution finished on fine Nagura slurry thinned, using AX and X strokes. It is simple, repeatable, and very effective. Depending on your base stone you may need to adjust the dilution and number of laps or if the stone is fine enough you can finish on the base stone, no nagura.

We use 2 layers of electrical tape to ensure you are honing to the edge. The next time you hone that razor you can use just one layer of electrical tape and one of Kapton. Kapton will ensure your tape lasts longer and does not burn through, so you are honing at the exact same angle throughout.

I think you will see an improvement in your edges.

Thank you Euclid.

While this thread is focused on Jnats, I want to testify that the technique you describe worked equally well with my coticule and la Lune.

I recently acquired a Friodur 50 1/2 in very nice condition, but certainly not shave ready. I was able to take the edge to comfortably shaveable, but just could not get it to the next level.

I had no diamond plate with me so I followed your suggested steps starting with my coticule and slurry produced using the coti slurry stone. The finishing steps used my la Lune and its slurry stone. The whole process took under 15 minutes.

I don’t have the tech with me to produce microscopic photographs, but I can affirm that the shave was as comfortabe as I have ever experienced.

Wow, thanks Euclid!

As I told you, I'm actually very busy but, as soon as I'll have time to put my hands on an adequate razor, I'll follow your great tutorial step by step for sure and fully document it with microscope.

I'd also like to thank Euclid. I have a vintage Sheffield that I used with this honing method. My finishing stone was a green Okudo Asagi with a fine tomo nagura. The razor was very keen and wonderfully smooth. Great stuff.