Month: December 2021

One more for the natural stones. This is a dark green hard but strong cutting and fine Japanese natural stone that I got off of Buyee (proxy service that allows you to bid on Japan’s version of Ebay).

I’ve bought a lot of stones, and I’ve sold stones (but only on a break-even basis). The reason for the metallurgical scope in the first place was to resell an abundance of straight razors that I’d accumulate and sort and honestly grade stones. This green stone is really one of the very few “something for nothing” stories, as it’s a near full size stone that’s either nakayama or narutaki mine (but the characteristics match that of nakayama – a hard fine but strong cutting stone that’s very strong on slurry despite not being coarse – on water with no slurry, the stone is a bit harsh feeling. The bottom line is that this is as good of a stone as you will find for a japanese finish stone of the fine and hard nature, and better than a hatanaka stamped stone that I also had (though hatanaka stamps until recently were always uncommonly uniform and aesthetically interesting – I looked on buyee now years removed from selling stones and see that the hatanaka stamp is now being forged as it was present on misshapen and common stones. That’s too bad).

I think the myth about japanese stones being “30k” grit equivalent is finally not the norm when their fineness is discussed. They are similar to the best of the trans or black arkansas stones, but with a little better fineness and stronger cutting power on harder steels (japanese natural stones from the mountain with the best mines are between 15-20% natural aluminum oxide from volcanic ash. If you’re the grouchy western type that thinks that’s mysticism, that’s tough – they do actually have aluminum oxide in them, but not in the same concentration that something like a shapton stone would – it’s mixed in with SiO2 (which itself is in the neighborhood of another 60% of the stone matrix).

So, what was the win? This was an “unmarked” stone sold by someone who picked barber shops and after flaking some of the crud off of the end of this stone, it has a very old stamp that more or less just says “original whetstone” or something of that sort (The kanji isn’t on the stone in 6 places with bright new purple ink and it doesn’t say “nakayama super best gaijin magnet” or anything like that, it just clarifies that it’s from the original mountain and that it’s got its bona fides. This was $32 plus proxy and shipping fees. But no worries, I’ve had plenty of $400 stones that really were $250 stones and when I did finally sell this one, I sold it for less than half of what it should probably have been sold for. You can’t keep everything And I still have somewhere around a dozen japanese finish stones.

I’ve had around 200 japanese natural stones in total. Very few feel the same if you’ve seen enough to start differentiating them. I’ve not had a large stone that was quite as good as this one at what this one is good at (hard, releasing no slurry, but with a fine biting slurry that’s very practical if the slurry is kept).

A picture of what this stone does both on slurry and then on clear water is below. If the objective was to get this picture to near optical clarity, then the stone must be allowed to dry while the honing process continues.

Compare this Picture to the 8,000 Grit Waterstone

The surface of the older stone – a little dry swarf left on top. Many stones have this color of green, but the really good stones are usable and make things sharp. The same appearance is common from a modern lower quality stone that may scuff on the surface and release a clump of particles.

I cannot recommend buying japanese stones for no reason, unfortunately. I don’t think you get what you pay for from dealers, and on average, the new stones are not a match for picker-sold old stones (but the latter is the kind of thing where you buy 10, keep the two you like most, sell 6 and throw away the two that broke or delaminated either before or after you buy them).

What you find on proxy services is a good reminder that people in Japan don’t necessarily think the stones are worth as much as we do aside for some uncommon stones with rare characteristics. And you won’t guess what those are when you’re new, so you’re far more likely to overpay (at one point, I purchased a large atagoyama stone off of the proxy service from a hardware store – i.e., retail – in japan. $235. I saw the same stone, same stamp, same size on a continental european “japanese stone specialist” site for $900. What do you get for the difference? nothing – atagoyama is one of the few mines that had stones in such abundance that the stones were consistent in appearance and cutting properties after they were separate by grade.

Ultimately, if you have tools that can be sharpened by a high quality black arkansas or translucent stone, how much better is the resulting edge from a japanese natural stone? It’s not, it’s about the same. In fact, the best of the natural fine stones all land around the same place.

One more for the sharpening stone omnibus. The Dan’s Black arkansas, and a first quality one at that. Dan’s has the finest black stones I’ve ever seen. They’re not the fastest cutting, which is the way the rules work generally with good arkansas stones. In my book, a good washita does the step just below this well and faster than any “normal” oilstone that’s not a true washita, so I don’t have any soft spot for an arkansas finishing stone that’s a little coarse. They will all break in, but a fine one will continue to be fine even if you scuff it a little.

You can also consider the results of this to be identical to a translucent stone (I’ve had at least a dozen trans stones of decent quality). I’ve also had black stones from Halls, which I believe may be Preyda now – they are decent, but not quite as good as a first quality Dan’s and sticking with Halls, as that’s what I recall their label, the fineness was a bit less and on the ones I tried, a stray clump here or there could come out of the stone. I’ve not had that happen with Dan’s.

Translucent stones that pass light well are a safer bet – the lack of air space to allow light through that easily is hard to fake on a translucent and the only risk is whether someone may be selling you an entirely different stone. If a translucent stone only barely passes light, though, you may be in for something with more cutting power than you expect.

Arkansas stones leave a flatter groove, but are very sensitive to steel hardness. Their particles fight an even battle with 62 hardness iron carbides or steel matrix, or however you’d gauge it. Much lower than that (like a soft pocket knife) and even the stone used for this picture will raise a strong burr. If you run into that, light strokes to thin the wire edge and then go to a compound.

Compare this Picture to the 8,000 Grit Waterstone

It takes some time and skill to get to this finish level whereas the autosol picture, you just need to not have nicks beforehand. I think the day to day use of a trans or black arkansas stone for chisels and planes is more work than the results yield. Why? The washita cuts faster and nearly as fine, and as bloated as they have gotten in price, they’re still less cost (push the lilywhite aside) than a good translucent or black arkasnsas. And once you finish with the washita, have raised a burr and teased it off, a couple of swipes on softwood or medium hardwood with autosol or something similar and the edge is finer than the arkansas stone can create.

Back to the Dan’s black. 2x8x1 is my suggestion, but they’re expensive. It’s a lifetime stone if you don’t drop it. If the price is just too step, find a first quality dan’s combination with a soft stone for one half of the thickness and the subject stone here for the other half. The feel will be the same and 10 workmen would never go through half an inch of black arkansas stone in a lifetime. It’s just easier to use these stones when they’re raised in a case.

Which leads to one more point (aside from one more reminder that these will reward skill and you may have difficulty at first with them) – keep your stones in a case or covered. With the high hardness, one stray piece of anything lands on one of these and the first pull or push across it and you’ll have a tiny notch in your iron.

How long does a stone like this last planing when you take the time to finish the edge as above? about 85% of the footage planed that 1 micron diamond will yield. Yes, I know. It’s not the result that I wanted, either, but the discussion of properties changed in steel and the (other) unicorn to be chased at the edge to find miles and miles of planing beyond just finishing the edge, it’s not there.

But, these are nice stones and they do come into their own with really small tools and crisp corner carving tools.

One more thing (Columbo?) – if you bring a damaged edge to this stone, you won’t ever finish it. You can vary pressure and get different results, but if you lean on a tool too hard, you can actually create small chips along the edge. Firm to light pressure – but keep your feet on the floor. And – they’re not great stones for someone who uses a guide. All Arkansas stones reward touch. When you’re using a guide, you’ve mostly lost the ability to do that. Your skill comes in getting this stone only to work the tip of the tool. This skill is enormously aided by spending $15 for a very small USB hand scope (as in, hand held microscope) so you can see what you’re doing.

I tested plane irons 2 years ago to examine edge life claims. At the time, I also did some extra tests with different finishing stones, methods to see how much extra life is imparted to an edge with finer abrasives. It turns out to be relatively substantial, but also in planing effort – sharper is a large difference in effort keeping a plane in a cut, starting a cut, and in total feet planed). The test was actually a duration test, so I planed somewhere around 30,000 – 40,000 feet as controlled as is possible. The later posted CATRA testing on knifesteelnerds finds ratios much the same as I found.

Because some of the planing was with irons that have vanadium carbides, I used diamonds as the sharpening media. 1 micron diamonds was my practical finishing step – first on hardwood, then on a wonderful cast plate that someone provided along with the test. A cast or steel plate with such fine media needs to be really good – just attempting to flatten a plane sole and use it will not work – the texture on the sole will damage the edge somewhat during use and until you manage to wear the sole to a high finish, it’ll actually raise a burr.

Very few steels will raise a burr on 1 micron diamonds.

It turns out, they will also create an edge that outlasts any stone that I have (15-20% more edge life), but much like the discussions of the true applicability of the tests, in heavy work, you won’t be able to see that gain – only if you are planing continuous clean wood.

So, I haven’t really made any “official” classifications, but I’d call an 8k stone the fine standard, and the 1 micron diamonds, the standard for extra fine (and autosol on wood is surprisingly good at that).

Great edge uniformity – even if a little tooth around the turn, the apex is crisp and wear under normal conditions is uniform (there is no unusual damage that occurs due to the edge being sharpened by diamonds, though diamonds 3 microns or larger do start to result in poorer edge life).

My apologies for the different looking image. Windows versions (changing computers) forced an expensive turret camera replacement and this picture was taken just before the prior PC gave up the ghost. Same magnification, though, and same length of edge shown in the picture.

The one nice thing about very small diamonds is that they will leave a very fine edge on anything, including steels not hard enough to hold it. Natural stones, on the other hand, have much larger particles and steel hardness will go far in determining how fine the actual edge is. The harder the steel, the slower they cut and the finer the edge. Diamonds are like a disposable camera – you just use them.

Typical Price at time of posting (2021): $10 for a vial of dry lapidary grit. Avoid pastes or woodworking suppliers for diamonds – you don’t get much volume compared to buying vials or bags of lapidary grit. Use with any lubricant (a thin oil is nice, WD-40 is fine). Just the same, avoid any “Formulated diamond lapping fluids”. Most specialty fluids targeted at amateur woodworkers are nothing more than hydrocarbons bottled in little bottles and marked up horribly.

So, if they work better (by edge life, and by sharpness), why don’t I use them? I just don’t love the feel of a cast plate, but its effectiveness can’t be denied. A heavy hand on a cast plate can also cause small nicking in the edge (too much pressure), and if there’s any ambient dirt on something like cast, it will notch the edge on the tool you’re sharpening.

First to be shown in the “omnibus” is the typical 8000 grit waterstone finish. This sentiment is now out of date, but when I started woodworking, nearly everyone used waterstones in the hobbyist world and a king progression finishing at 8,000 grit or something similar was a standard paint-by-number suggestion.

I would suggest unless you’re really new and progressive and these types of stones aren’t something you’ve seen, this is your standard to compare other finish stones to. There are finer, and there are more coarse, but there’s nothing in hobby woodworking that this won’t cover.

This stone is the “kitayama” stone sold by imanishi. It’s very inexpensive in japan, sometimes marked up here.

Edge uniformity is decent, but the slurry makes the edge itself a bit toothy.

The stone with slurry dry – the markings on the surface will wear off, but I’ve since sold this stone. This stone works far better with slurry of its abrasive than just with clean water.

If you keep something to level the surface of this stone handy, it’s easy to use and wide for beginners using guides. It will gouge fairly easily, though, and is limited if you move to things like carving.

Typical Price at time of posting (2021): $60.

If you see this stone listed for much more than that, you probably ought to consider what else is marked up. Sometimes that’s an issue of distribution and not retailing, but retailers with prices near or above $100 for a stone like this are generally high on everything. I’d refer to those types of retailers as beginner’s traps – they have catalogues and lots of advertising, and are trawling a net to continuously find new customers.

Last year or the year before, I took pictures of the scratch patterns from a lot of sharpening stones. Most of them, I still have, but I have the pictures nonetheless and more can be added.

At the time, I posted on a woodworking forum a “sharpening stone omnibus” or some such thing. It didn’t generate that much discussion, but when I’m exploring, it’s never a matter of seeking adulation, so that’s not a problem. What I’d hoped (And did nothing to facilitate) was some visual record of what sharpening methods do as there’s nearly no correlation between cost of sharpening method and speed or results (fineness). At the time, I showed that with psa 80 grit (as a grinder) and a throw-away fine india stone and a white buffing stick that I bought for $0.99 off of the Sears clearance rack was finer and just as fast as anything. The india stone came in a group, but if you had to price it, you could claim that it was a dollar (what I wanted from the bag of stones was some natural stones and those were already a bargain).

So, more in the spirit of showing what natural stones do, and providing information and maybe preventing expensive unnecessary purchases, I am going to gradually repost and index the results here.

There are a lot of debates about what stones are fast for fineness, or so and and so forth (for example, on a razor forum that I once visited, the strong notion existed that only the naniwa chosera mid stones were worth having unless you were short on money. This is, of course, not true, and the microscope will show a razor edge before and after a shave). I’m generally avoiding the middle honing and the grinding, though – it’s always the search for a magic fine stone where people dump huge amounts of money.

And if that’s what you want to do, that’s fine, but you’ll be able to see what you’re getting.

What I found in general is that when you have a fine even matrix somewhere around 1 micron, then all but tiny scratches at the very edge of a bevel disappear. There is a whole lot out there that’s cheap and strong cutting that’s in that fineness, unlike 75 years ago. And there is no natural stone that will outdo synthetic grits if you want to chase fineness and edge longevity in push cutting (planing). It’s a hard truth, as I’ve spent as much as $700 or a little more on a single sharpening stone (not often) and that amount or a little less may be very typical for rare natural stones or the more highly marked up Japanese stones. Those rare stones are wonderful to use – and the more stones you’ve been exposed to, the more you start to notice the wonderful different feels and smells of various natural stones, and the quality (as in, properties other than outright sharpness) of the edges they give, and the aesthetics of a laminated edge that they can be manipulated to perfect. But for outright blistering sharp, you can get that for less than it costs for a nice lunch.

Unlike most claims of woo, I have the microscope pictures to prove it, and at one point in a group of tests planing tens and tens of thousands of feet of wood and taking edge pictures, I have the longevity data to settle the argument about whether or not some special transformation of edges happens under certain natural stones. Unfortunately, it doesn’t. Any burnishing or adhesion that’s done to an edge is something worn off quickly when planing wood.

Just as a teaser – below are two pictures – one is an edge on a slurried very very expensive very fine and hard japanese suita. The other is an edge created more quickly with a washita and autosol compound on wood. You can guess which is which (and while the pictures may change slightly with technique or no slurry, etc, and lighter pressure), the overall theme doesn’t change.

What you’re looking at is the backs of two plane irons photographed under a metallurgical scope at 150x magnification. The length of the edge is around 2 hundredths of an inch. The only thing that really matters is the edge and a couple of thousandths behind it – basically how even the line is dividing light from dark.

The little black bits that are irregular are just dirt or fibers from clothes or a rag after cleaning an edge – I didn’t always get everything cleaned off completely, and doing so is actually fairly difficult as the lightest amount of oil will look like bubbles all over the magnified surface.