Sharpen the Miki hisa folding knife using the King man-made/natural waterstone

Inertia has set in big-time. I've been working on my blacksmithing (Tong forging mania!! Interesting, no?), the to-do list just gets longer, and some of my projects have been on the back burner so long that I've no idea where to begin (again!). In addition to all that, the shop is getting so packed full of stuff that it's getting hard to find room to move, yet alone get some work done. EBay, here I come! I need to work on my meager photography skills. Certainly no lack of things to do, but where to start?

I know! Let's sharpen something!



A while back, I bought a peculiar looking waterstone. You can't have too many natural waterstones (or kanna, or chisels, or odd bits of wood/rusty metal/screw's/nails/files....), right?

Odd looking, to be sure. I thought that it *might* be a Japanese natural waterstone....

.....but it's not :'( 

What I thought was a manufacturer's INK stamp (first photo), is actually an IMPRINTED stamp. Bummer!

It's a weird stone, though. The fractures are probably due to freezing, but might just be from sitting too long in the water tank. It has the feel of a stone that doesn't want to be permanently wet. The fractures *look* like something that you see associated with old aotos, showing vertical cleavage planes and a somewhat coarse structure. It doesn't have the uniform grain of most man-made waterstones. Now that it's all cleaned off, it's composition is obviously very homogeneous. Definitely man-made.


Prior to bidding, I did a fairly thorough search for artificial waterstones with similar color, size, and markings, but didn't find any matches, so I was somewhat optimistic that it would be a natural stone. Oh well. Since I already have more synthetic stones than I can use, I set the stone aside for a while. A few days ago, this popped up on one of the Japanese sharpening stone blogs that I follow.....

We have a match! The gist seems to be that it's an old, unusual, King brand waterstone that is made from reconstituted natural materials. I guess that I was partially right, haha! In any event, my interest was renewed. And, yes, I actual read blogs about sharpening.......


The stone is 210-68-40 mm and feels rather light in weight, with an odd grainy, soft feel to it. It puts me in mind of a big chunk of powdery chalk, and feels too soft to be very practical as a tool sharpening stone. You can see how dished it is. It's obviously been used for sharpening knives, so.......



For ages now, my pocket knife has been one of those plastic, breakable blade disposables.

Even a $-Store craft knife can be improved by a little sharpening. A couple of swipes on a fine diamond stone will work wonders! The problem now becomes that the plastic body of the knife wears out faster than the blades do. And..... Plastic.

I sharpen disposable blades. My name is Jason and I have a sharpening addiction.......


I  got this a few weeks ago.

A Miki-hisa folding pocket knife, nothing special, but decidedly nicer than what I have been carrying. Mass produced, but with a laminated blade and a Bubinga body, after a bit of massaging it seems OK. I relieved the sharp metal edges and reshaped the body some, until it felt better in the hand, and while I wouldn't pay full retail for one ($40'ish), I thought it worth the $12 I paid.

Amazingly enough, I have had this for 3 weeks and it STILL has the factory edge! It's time to try out the new "mystery" King waterstone!


But first, some ground work. I use the Po'boy #125 diamond lap (loose diamond grit on a maple wooden block) that I wrote about before.

T=20 seconds. A minute on this is sufficient to remove most of the coarse factory grind.

Before I get too carried away, I need to work the hollow ground back of the blade. I start on a #400 Eze-lap. On the right edge of the stone, you can see a strip of black electrical tape. This is to keep the upper (curved) back of the blade contact to a minimum, at least for the roughing stages.

This being a cheap knife, the blade has a pronounced curve or hook towards the steel side,  so not only is the back of the blade hollow ground, it's also bowed along its length. This makes it pretty well impossible to make the back truly flat without making the urasuki all misshapen and ugly. 

I go for looks, cheat a little bit, and only do the minimum required to establish a small flat at the cutting edge of the blade (the lower, straight edge). The back is still slightly bowed, but it is adequate.

From the #400 grit diamond stone, I go to the oddball King man-made/natural. It is a very open bodied stone and needed to be soaked for about 5-10 minutes before using. It's very porous. 

And interesting....... Nowhere near as soft as I was expecting. I thought that this guy would  fall apart and be a heavy mud producer, but that wasn't the case, at least with this blade. It felt moderately fast, but without being aggressive. A soft, rough stone. Weird. You can feel the grainy nature, but it isn't scratchy at all.

An analogy: If carborundum/ silicon-carbide is a handful of finely ground glass, a typical aluminum-oxide stone would be a handful of fine beach sand. This stone would be a handful of dirt, or maybe sawdust.

The finish is in the #1000-2000 range, but the scratches are shallow, not sharp. This thing serves the same purpose as a coarse aoto. It would act as a bridge to transition from a sharp and scratchy synthetic stone to a natural finish stone. I strongly suspect that was the intention of the manufacturer. 

I would like to try this stone out using a hard kanna blade, but both the top and bottom surfaces are WAY too dished. This thing is shaped like an "S"!

Sticking with the "odd" theme, I use one of my favorite Oregon beach stones next. This was a bit of a step back, grit-wise, but served to confirm the relative grit finish. I didn't want to wait for more synthetic stones to soak. Most of the natural waterstones are splash-and-go.

I consider this stone to be around #2000, but a touch scratchy and the density is uneven. I still like it though.

And another Oregon natural waterstone to finish.

Good enough for a pocket knife.

More home-brew diamond sharpening stone stuff....

Still goin'....



Call me masochistic, a slow learner, what ever.....I have a problem with wanting to reinvent the wheel.

The acrylic showed some promise, but maybe can be improved? This time I used a file to prep the surface, leaving a scratch pattern that was perpendicular to the primary axis. Side-to-side, as it were. I was thinking that maybe the grit would set into the substrate more evenly.

A sprinkle of gems...

Then set, using a hardened steel roller. A large roler bearing, mounted on a handle is what you SHOULD be using, but.....

This time, I just sprinkled the grit loose, no glycerine. I had a chip-breaker/back blade/secondary blade (laminated construction, just like the main blade) that I had shortened, so am setting a whole new bevel here. Well.....I hog out most of the material with a grinder first. This is refinement, I guess. Babbling..... Sorry.

I rinse off the accumulated swarf and any loose grit that still remains, then have at it again. 

Yep, it works. The action is peculiar, like the blade is riding in tracks, on rails, so I try to incorporate a swirling or erratic stroke. This can speed up the sharpening process (think "random-orbit" sander vs the older vibrating palm Sanders), but it is hard to maintain a flat bevel this way. That's why the scratch pattern looks all screwy.

Maybe acrylic isn't the best material, or maybe this stuff was too hard. The material that is commonly used for a lapping plate varies. Balsa wood, copper, brass, even lead, it all depends on what you are lapping and what you are trying to achieve.

MDF

I liked this MUCH better. The grit bedded down well, possibly too well? The scratch pattern tamed down quickly, probably because the larger grains bedded more deeply during use. This combination felt more like a sharpening stone, but still not particularly fast or aggressive.

Derek Cohen has a great writeup on his blog, about making lapping plates from old cast iron plane bodies.

http://www.inthewoodshop.com/WoodworkTechniques/Castironhoningplatesfordiamondpaste.html

A cast iron clutch plate. Cast iron is made in a whole variety of hardnesses and densities. I think that a "soft" iron would be nice to try. This clutch plate is pretty hard.

It works. It feels like the diamond is mostly rolling around, and only a portion of the grit is getting embedded into the cast iron. If you look at the bevel, you can see a division between the soft iron and hard steel laminations, just like you would see if you were using a waterstone. It is the loose grit, tumbling around and putting microscopic dents into the iron, that gives the characteristic "hazy" look that is so pronounced with a laminated blade.

It works dry (see above)...

.... And wet. The viscosity of the fluid used to lubricate and flush away the swarf can have an effect on the "feel" of the lap, and the appearance of the blade itself. This is using a (relatively) thick oil, 10w40 synthetic motor oil.

I liked this combo for the "push". It felt like the high viscosity slowed down the rolling action of the grit. It left a more even haze to the iron. Compare the even, gray look of the soft iron to one of the pictures of embedded grit/acrylic substrate. The embedded grit leaves a very shiny/scratchy finish. I think that it's soooo cool that the same material (#120 diamond grit) applied differently, can give such different results.

This is using a thin oil, mineral oil cut 50% with mineral spirits. Is about the consistency of WD40. 

It feels different, looser, light, and very rumbly/roly/crunchy. And VERY messy. The appearance of the iron is more scratchy and not as fine as when used with the thicker oil. It still feels like only a small proportion of the grit is getting embedded into the cast iron substrate. This is a great combo (a cast iron lap w/diamond grit) for finer grit, something like a #400 and up. This coarse...... Not so much.

And a piece of maple plywood. 

The diamond grit embedded well into this material, as is evidenced by the uniformity of the bevel face. There is almost no visible line between the soft and hard metal. That means that the grit stayed anchored and actually sheared the metal, as opposed to rolling. This combination felt the most similar to an actual diamond sharpening stone. That said, the aggressiveness still quickly diminished as the diamond grains got pushed further into the substrate. 

My ideal would be this stone.....

... just a bit harder. Super fast, sharp grit, and fun to use (and it looks like a rock! I love that!), but too soft. It dishes quickly and gives up too much slurry, which gets in the way. I need to get back out to the beach, and find some new "real" stones. Like this one, but harder.

Kiridashi E/R- An old Japanese craft knife gets a face lift

I need to remember to take better photos. Sorry for the lack of "before" shots.....


Close to the center of the photo is a wooden handle, single edge knife, a kiridashi.

Probably nothing too special, just a good knife. My friend Junji has been looking for a decent knife for me, and knowing my tastes in tools, he found me a good, old one.

The mei (name) is a bit stylized and hard to read (not that I can read kanji, but I am starting to recognize a few symbols).

A screw acts as a retainer, holding the blade in place. A bit of  #0000 steel wool cleaned the grime off of the handle, then I rub in a bit of BLO ( boiled linseed oil).

There was no finish to speak of, so I give it a quick soak in some vinegar. 30 minutes was all it took to remove the bit of rust and leave the metal clean and lightly etched.

I gave the blade a blackened finish. I like the look, but it also helps me with the initial sharpening by acting as a reference mask, like machinist's dye.

The blade has a wicked hook to the steel side. The two layers of metal, steel and iron, contract at different rates when quenched by the blacksmith. This causes the blade to warp towards the harder steel side. I want to make the blade's back flat, right at the cutting edge (the uppermost edge in the photo above). A lot of the blades that I see have been done poorly. It's not difficult, but does require a bit of thought and intent.

Grinding down the edge left the steel a bit thin at the very tip of the blade, which could lead to poor edge retention. 

I grind a new contour to the back, turning a flat line into a gentle curve. You can see that the right side of the blade is no longer straight. The camera angle makes the curve look rather abrupt. 

After the rough grinding with a fine India stone, I finish sharpening the blade using native Oregon coast waterstones. 

But first.....

What's in the box?

HAPPY ROCK DAY!!!

My family know how to make me smile.

But whatever in the world will I do with a rock?

Yeah, I know.....

This stone looks identical to another chuck of sandstone from the front yard, but actually finishes slightly finer. This one will go up to around #8000 grit, if you work on the drying slurry bed.

I am really liking these stones, but I am running out of space. I need to build a stone storage rack or something....

Just for fun, I finish polishing the edge using the Nakayama asagi mystery whatever-it-is "Asagi of indeterminate origin" stone.

Sooooo nice. This stone is FAR above my pay grade. I am getting spoiled....

My first project is a foam quadrupedal octopus.

Actually it is a quick and dirty, duct tape sheath. This blade actually scared me, it takes such a fine edge. I was afraid the I might bump into it, requiring a quick trip to the hospital.

The bevel angle is about 27 degrees, pretty fine, and I will be curious to see how well the edge retains its sharpness. This is easily the sharpest tool that I have ever used. In any task of a reductive nature, much of the difficulty lies in directing the tool, I making it do what you want it to do. Cut here, not here, that sort of thing. REALLY sharp tools just cut, right where you want them to. Please let me never suffer dull tools, ever again.

The search continues..... continues

So, where were we?

Sandstone from the Oregon coast, found in my front yard (hopefully not my wife's favorite landscape design element). Very easy to process, not too hard and very homogeneous particle composition. Density is also very even. Not overly thirsty, nothing like the other local sandstone that I use. It looks like it will be about #1000-#1500 grit? If I wasn't familiar with the OTHER sandstone, I would guess #150 and scratchy as hell, haha!

Pretty smooth, easy to use and a surprisingly fine finish. No scratchy bits!

A diamond nagura seems to speed things along. This stone is not very porous, surprised..

Much finer than I was expecting! 

A different angle. I am TRYING to get the light right, to show the scratch pattern. The pattern is still uneven, though, because I haven't actually flattened the bevel yet. A perfect example of why a flat bevel makes things MUCH easier in the long run. I can't imagine how a person would get consistently fine results with a less than flat plane/surface.

W/ODC nagura

This is turning out to be a very easy stone to use! Very forgiving, VERY even, reasonably fast (especially considering the fineness!)

A fresh look using a different, harder blade, polished very fine with my Ozuku asagi.

This is as fine as I can get with a natural stone. Ozuku asagi.

NOW we'll step back to see what sort of a scratch pattern this sandstone leaves.

I need to think of a name to reference this stone.... Anyways, this is the new sandstone again, using the ODC nagura. A bit slower with this harder blade, but not much. This is maybe #5000-#8000? The scratches still look very prominent.....

But it is actually very reflective. Steel is bright mirror, iron is moderately hazy, probably due to the ODC as much as anything.

So, there you have it. A very respectable rock! Not perfect, but you could easily call this your final finish, AND I found it about 20 feet from my front door! A bit of mud, but not muddy, just enough to give a slight cushion. Water  management is not an issue, so no soaking is necessary. No real tendency to dish either.

I love finding these things. The whole process is so unlikely, it still just amazes me. I just need to fill the empty hole in the rock border with one of my "failure" stones before my wife notices.....