Wednesday, 7 October 2015

Edge Joining, using a Nagura set and getting the most out of your Japanese natural stone

Here is a article on maxing out a Jnat to get the keenest edge possible. It's not something that needs to be done on every razor and I would generally recommend this way of finishing to more experienced Jnat users that are trying to get the most out of their stone. This applies to most natural stones.

In this progression I've decided to use a full set of mikawa naguras on my Wakasa asagi which I don't do often, this may be a bit of an overkill for me but it never hurts to make sure you've done enough prefinish work to prepare your blade for a final polish, you do not need to go through an entire nagura set, infact you can go straight to your base slurry on your stone, start with a heavy slurry and progressively thin it out, for the purpose of this article, I will use the whole set. In this case the razor I've chosen to use is a Japanese made Parker due to the fact that it was the dull razor that I had lying around.

I've started by setting the bevel on my Atoma #1200 diamond plate, a new primary edge has been established. The scratches are deep and the edge is very harsh and toothy as expected but this is only the beginning.

Here I have drawn the edge across the stone, this is called edge joining. It eliminates the toothiness but it comes with a price. Your edge becomes completely dull.

The next task would be to reset the bevel on a whetstone of a similar grit. The purpose of this is to convert the harsh diamond scratch pattern into less aggressive scratches, in this case it was my chosera 1k which will also re-establish the bevel using a minimal number of strokes. In the next photo the edge is no longer dull. 

Now it's time to move on to the Wakasa and Mikawa naguras. I raise a slurry using a Botan. I do a series of 20 circles for speed cutting and to also allow the slurry to break down and become finer followed by 20-30 x-strokes. The 1k scratches are very faint and mostly remain behind the edge, by that stage it's time to move to the next progression or you can keep going until the scratches are completely gone, that is up to you.

I move on to the Tenjyo, mejiro and Koma and do about 30-40 x-strokes through each progression. By the time I was done on the Koma, the edge has taken a better polish, it's ok to strop and shave from here but I would recommend raising a slurry from your base stone with a tomo nagura or a well worn diamond plate as the final polishing stage for extra keenness.

In this case I have used a tomo nagura on my Wakasa and did the same thing, worked the slurry until it became finer and thinned it down with water. By then it the edge was highly refined and more than ready for a shave but this time, I have decided to squeeze as much keenness as possible out of my stone, I went to plain water and performed about 10 x-strokes, by then I felt suction under the blade, this is a good time to stop. I stropped the razor on clean leather doing 10 passes. This slightly rounds or creates a slight convex at the very edge, this eliminates the suction on the stone for the next few strokes. I went back to the stone and did another 8 strokes under running water, that was all it took to bring back the suction, this ensures you have the same results throughout the entire edge. This is my preferred way of getting the most out of my stones and here are a couple of photos of the finished edge which has taken a very high polish. 

Thursday, 25 June 2015

My review on the Tsushima Black Nagura slurry stone 対馬砥石

The Tsushima Nagura is unique in it's own way for a few reasons, let me tell you why. Firstly, this stone was quarried from an underwater mine in 1983. It has been used quite often by traditional wood workers for sharpening their tools (as well as many other natural stones).

This Nagura acts in a similar form to a Tenjyou 天上 or a Mejiro 目白which I assume will raise the question, what is the purpose of using one when you already have a Mikawa nagura set?

I have used the slurry from the Tsushima nagura on my hard Narutaki toishi. First off, here is where it lacks some goodness, the colour of the slurry is light grey which can be deceiving with swarf and it is slower than Mikawa naguras so it will take more time to cut when you're only using it for you mid-work on a razor, but why would you when it's capable of so much more? 

Here is where it shines, the slurry from this stone does NOT stop breaking down and keeps getting finer and finer to the point where you could easily finish on it, opposed to a Mikawa nagura where it will cut faster, break down quicker and the slurry will also dull quicker forcing you to use your next nagura in your progression, not to say it's a bad thing at all but Mikawa naguras work better in a set. The Tsushima slurry just lasts and can fit in many different progressions, for me, it will work straight after the Botan ボタン and once the slurry has been broken it can replace the Tenjyou, Mejiro and Koma, even the Tomo nagura depending on the level of abrasion and grit fitness of your tomo. 

On softer steels I have successfully used it straight after the bevel set for a one stone hone, in this case the Chosera 1k and was able to finish on a harder base stone with the slurry from the Tsushima which resulted with a HHT 3-4 prior to stropping, and a solid 4 after stropping on linen and leather. What I also did notice that it left a very high polish on the bevel, comparable to my 10k Chosera which I found to be quite odd for a Japanese natural stone as they generally leave a hazy sandblasted look to the finish, another indication of the slurry getting very fine. Refer to the photos below.

Overall the Tsushima works as a great pre-finisher or a finisher and provides great feedback, although many do claim that they're quite rare, I don't find that to be the case. They're priced quite well and are quite uniform, consistent, clean and generally free of toxic lines or inclusions. You may contact me if you're on the search for one or even the full size Tsushima and I'll do my best to assist you. Hope this helps. Mark

Photo of Tsushima Nagura finish at 400x

Standard photo of the bevel

Wednesday, 11 February 2015

My review of the Apache Strata

First Impressions

I knew that this stone was solid as soon as I picked it up. The stone had arrived pre-lapped which was very convenient and the finish was smooth to the touch, I lapped it again anyway just be sure.

This stone does not require soaking, just spray some water on the surface and away you go. When you draw the razor on the stone it felt like glass, almost felt like it wasn’t doing anything, but be careful this is very deceiving at first! The urge that you get from this stone to use pressure will almost dull your razor and will force you to take a step back, it only requires a gentle touch and very few strokes.

I used my Sheffield near wedge as an example to test the waters and gave it about 30-40 laps with just the weight of the razor as it was due for a touch up. I was surprised to see it snapping hairs whilst tree topping. HHT isn’t something I rely on as a solid reference. I then decided that I will place it under a microscope for a quick peek and to my surprise it was a very good looking edge so I took a few snap shots. Here is what I got at 400x magnification, the photos were taken from toe to heel on both sides.


 I understand that some of us don’t use microscopes and prefer not to. Is it a requirement to have one? No, but I'll use it just about every time I test a new stone it’s a good perk and gives you a good guide line of your work as a rough idea such as the scratch pattern or to check for microchips on the edge before the shave, if the edge has visible flaws, then going for a shave is a waste of time unless they're fixed.

Initially I wasn't happy with how the bevel looked aesthetically, I even considered using diamond spray or CBN to clean it up but I didn't find that necessary as the edge looked pretty good and I wanted to see how the razor would shave off the stone with no further refinement. 

The one mistake that I have made was using Chromium Oxide after finishing with the stone, after reinspecting the edge, that was a mistake, there was no improvement and again, the edge didn't need further refinement. 

All in all, this is a stone that you will need to figure out for yourself. It shouldn't take you long if you love your naturals, it has great cutting power for a finisher without slurry. Use it with water, you may experiment and add lather or glycerine but I found water was good enough. The trick is to be a minimalist when playing around with it as you can over do it.

I don’t believe in grit levels when it comes to naturals but my Strata is more than fine enough as a razor finisher. If I could change anything on the strata it would be consistency, the finishes and shaves differ a lot from one razors to the other. 

I recommend using the Apache Strata after a synthetic progression. I personally have achieved great results by honing that way but you will need to experiment yourself to see which method is more consistent for you but this will give you a head start. 

The Shave

I know this sounds cliche but this was a very smooth shave, the edge was keen enough. I was able to improve a Chosera 10k edge. Trouble spots were no obstacle, the shave was very close and comfortable with no irritation. 

Update (18/04/15): After finishing a handful of razors on the Apache Strata, I found that I was getting better results using a drop of glycerine on the honing surface with water, the stone is exceptionally hard and light to no pressure is a must. I recommend that you don't use slurry on this specific stone as edge dulling will take place followed by possible micro chipping due to the hardness of the stone. This stone needs constant resurfacing due to the surface glazing from metal particles being left behind in the pores, this is where glycerine comes into play by keeping the swarf off the stone which reduces clogging. Overall, there's no doubt that this stone works as a great finisher when handled with care and a bit of thought. 

Personal rating:

Cutting Power:        9/10
Feedback:                7/10
Ease of use:              9/10
Price:                        8/10
Finishing Results:   8/10

Overall Rating:       8/10

Estimated Hardness 5++
Grit Fitness 4+ to 5-

Disclaimer: This review that I've volunteered to do for which is based on my own personal experience only i.e my razors and my stone(s). I have no affiliation with  nor do I get paid or receive discounts to review stones. My review is there for some guidance to provide as much info as possible prior to shopping for a stone. Note that all natural stones of the same sort and the same mine or quarry can and will vary from one to the other, providing a different experience with each individual piece, results will also reflect the experience and technique of the end user.