Monday, June 2, 2014

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.

1 comment:

  1. Nice knife Jason! Bring it by the boat sometime. I love knives almost as much as I like planes.


Like all of us, I am figuring this out as I go, so when you see something that is incorrect or flat out wrong (and you will!), let me know. This is a learning process. Real people and names, please. Constructive comments and questions are very welcome, but hate speak/politics are not! Life (get one!) is too short.

Thanks, Jason