Sharpening of the garden-variety?

Ah, the sharpening. Here's where you can discuss sharpening stones and media, along with sharpening techniques.
Vips
Sweeper of Floors, Maker of Tea
Posts: 63
Joined: Tue Mar 31, 2015 3:48 am

Sharpening of the garden-variety?

Sat May 21, 2016 6:00 pm

It seems the topic of sharpening is something I consider on almost a daily basis. Perhaps it's because it's actually quite difficult to get out there and try all the different media and all the varieties within each type. It also doesn't help that I'm currently making do with a Sigma 1k, which I do enjoy, a 6k Sigma Jinzo-renge-suita, which is in two halves, and what I believe to be a 10k sold as a 13k. The 6k/13k was a dual sided stone which delaminated from each other a few months into use. Although not in great condition, I've managed just fine, but naturally I was looking for replacements.

Now I'm sure this is the part where most will consider me bonkers, but I decided to try the whatever was lying around in the garden with a beat up chisel. I wasn't expecting to find anything useable, simply a childish experiment. I did come across a slate which was there as a decorative feature. I decided to to flatten a section of it and 'see what happens'. I managed to bring up a slurry after flattening, and I proceeded to sharpen. I was quite surprised to see some cutting action. After a few minutes, I noticed a hazy bevel. I figured this was at best between 1-2k, until I did the usual arm hair shave, and found it popped a hair off with no pressure! I know very little about natural stones, clearly, and so was left a little confused by the finish and it's corresponding sharpness. I went on to try a japanese marking knife and then one of my kanna blades. This time, I sharpened for much longer, to see if this hazy finish would change, it didn't. However, when I looked through a loupe, I noticed unlike the bright mirror like finish, which usually has a few larger scratches from the sigma finishing stone, this was a very consistent haze, with no larger scratches.

I'm sure some of you with natural stones may have some more insight into what I have here, but so far I'm extremely pleased with the results. It's perhaps placebo, but it does seem like the edge is longer lasting.

Anyway, here are some pics, and even a video!

Image

Very difficult to photograph, but there's a nice distinction between the steel layers.

Image

https://www.youtube.com/watch?v=aZze5KFW44g
User avatar
Brian
Deshi
Posts: 1090
Joined: Sat Nov 29, 2014 11:46 am

Re: Sharpening of the garden-variety?

Sat May 21, 2016 7:36 pm

That's wild, I think the trouble you may have is that the stone will dish very easily. Finish stones are usually deep strata (Suita) and very compressed so they are typically hard.

It's nice to find a medium finisher which cuts fast and self slurries but doesn't dish.

Welcome to the insanity, Chris nudged me in this direction over a year ago and a deep dive later I am very much enjoying myself.
djwong
Deshi
Location: Cupertino, CA
Posts: 134
Joined: Wed Feb 01, 2012 12:52 pm

Re: Sharpening of the garden-variety?

Sun May 22, 2016 12:05 am

This person has some older entries in his blog on "found" sharpening stones.

http://mypeculiarnature.blogspot.com/se ... Sharpening
Vips
Sweeper of Floors, Maker of Tea
Posts: 63
Joined: Tue Mar 31, 2015 3:48 am

Re: Sharpening of the garden-variety?

Mon May 23, 2016 9:09 am

Thanks David. It looks like the individual behind that blog is a bonkers as I am!

I've used the stone several times now, and it's considerably harder than the sigma 13k, which you could gouge simply by looking at it, hehe. I've made a nagura stone, which helps polish and raise a slurry, which really speeds things up. I now understand what you mean, Brian, regarding natural stones, it really has me wondering how well natural medium grit stones are to work with.
User avatar
Brian
Deshi
Posts: 1090
Joined: Sat Nov 29, 2014 11:46 am

Re: Sharpening of the garden-variety?

Mon May 23, 2016 6:38 pm

The real victory of natural stones is a very wonderful edge off of a medium-fine finisher. Not a medium stone like a nagura stone, but a medium-fine like a fast cutting suita. My asagi is wonderful but it's just for the fun of putting a crazy edge on something.

When I am referring to hardness I'm really referring to dish resistance, in that way the sigma 13k is fairly 'hard' it does scratch easy but thats another matter. Natural finish stones are more dish resistant than sigmas in my experience.
Gadge
Sweeper of Floors, Maker of Tea
Location: Sydney, Australia
Posts: 70
Joined: Wed Jan 28, 2015 5:35 pm

Re: Sharpening of the garden-variety?

Mon May 23, 2016 6:54 pm

Hi Vips,

You've got yourself a natural water stone!

I've been quarrying stones for my own use for some years now and have given a few to members of this forum. Natural stones are basically shale or mudstone or slate. The hazy appearance you describe is the finish of a natural stone. You can split the stone by getting it to cleave along the strata lines then finish up with a diamond stone. you can also cut it to shape with a diamond blade tile cutter or buy a tile saw blade for your hack saw. I use a diamond stone as a nagura to keep the stone flat and produce a slurry.
I don't think it is a placebo, the edge should hold up very well using this stone.

Congratulations!
Vips
Sweeper of Floors, Maker of Tea
Posts: 63
Joined: Tue Mar 31, 2015 3:48 am

Re: Sharpening of the garden-variety?

Wed May 25, 2016 5:15 am

Thanks Gadge :)

There happens to be another stone, which looks very similar about 5 times the size of the one I am using, I will try that one at some point too. I've also tried several other stones, and found a couple of great medium grit stones, which cut well. I've been using the back of a tile with grit in powder form to arrive at a rough flat, which I finish off with my Atoma. The more I use the finishing stone, the happier I am with it. So far, it dishes at the same rate as the sigma, and is not much slower, but leaves a much nicer appearance. I'll definitely be on the hunt for more when I'm out and about.

Do you have any pics of the stones you've found to date, Gadge?
Gadge
Sweeper of Floors, Maker of Tea
Location: Sydney, Australia
Posts: 70
Joined: Wed Jan 28, 2015 5:35 pm

Re: Sharpening of the garden-variety?

Wed May 25, 2016 6:30 pm

Hi Vips,

I've attached a small presentation I made a few years back. Since then I've found another deposit which yields better stones than these. Not top of the line toishi but not a long way off either.
Gadge
Sweeper of Floors, Maker of Tea
Location: Sydney, Australia
Posts: 70
Joined: Wed Jan 28, 2015 5:35 pm

Re: Sharpening of the garden-variety?

Wed May 25, 2016 6:39 pm

The PDF wasn't accepted so I'll post a couple of photos.
Attachments
yellow finisher.JPG
The yellow stone is mudstone and cuts fast with medium finish.
yellow finisher.JPG (83.33 KiB) Viewed 5732 times
Slate finisher.JPG
The slate stone is very fine but doesn't cut as past as the yellow.
Slate finisher.JPG (77.33 KiB) Viewed 5732 times
Vips
Sweeper of Floors, Maker of Tea
Posts: 63
Joined: Tue Mar 31, 2015 3:48 am

Re: Sharpening of the garden-variety?

Fri May 27, 2016 10:08 am

Thanks for those Gadge. From now on, I'll be keeping an eye out on my travels. I'm quite pleased with the sigma ceramic 1k, but it does need to be soaked, so there's usually a little wait involved. I usually use this time to consider the condition of the blade from the last sharpening and if there are any changes to be made such as camber.

When you are out looking for these stones, are there any tests you carry out to confirm whether the rock will be suitable?

Return to “Rocks”

Who is online

Users browsing this forum: No registered users and 4 guests