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Japanese Skiving Knife Repair

Posted by is9582 on January 11, 2018 with No Commentsas , , , , , , , , , , ,

I have a really beautiful Japanese skiving knife that my daughter and son-in-law bought for me, while in Japan a couple of years ago.

 

The bevel side of the blade on the Japanese skiving knife.

The bevel side of the blade (already sharpened) on the Japanese skiving knife.

 

The back side of the blade on the Japanese skiving knife.

The back side of the blade (already sharpened) on the Japanese skiving knife. Wooden stop at left (next to the corner of the blade) is used to set blade projection for this tool, when in the Kell honing guide.

 

I was using it to thin some leather from a piece where it would blend with a joint, and I noticed it wasn’t sliding through the leather like it had when I got it. My eyes aren’t what they once were, so I looked at the knife’s cutting edge under some magnification, and what I saw just blew me away! The edge was chipped something terribly!

 

This is the cutting edge of my skiving knife, before repairing the chipping.

This is the cutting edge of my skiving knife, before repairing the chipping.

 

I’m the only one who has ever used this skiving knife and I always handle my tools very carefully, and it has never fallen from the workbench or come in contact with anything other than leather. I even made a leather sheath for this knife when I received it, so it would be protected.

 

The Japanese skiving knife in it's leather sheath I made especially for it.

The Japanese skiving knife in it’s leather sheath I made especially for it.

 

It is possible that the steel used in this skiving knife is not flawed at all, even though it would seem at first glance that the heat treatment possibly left the blade too brittle. This isn’t uncommon in the blade making world, as the outside (what I might call a skin, for lack of better terms) can be a bit too far towards the brittle side, but once this skin is removed, the remaining body of the blade is both hard and resilient.

 

Ok, so how the heck can I fix this, without spending hours at the water stones, and without using up half a stone? Now this is going to sound crazy to some, but you hold the cutting edge perpendicular to the 1000-grit water stone, and move the blade down the stone. I know someone is cringing just thinking about doing this to a blade, much less with the damage it will do to some water stones, but stay with me here. This is one of the places that the Shapton Glass Stone series of stones really rock (not that they don’t rock all the time), when you have a narrow tool (something like a 1/16″ chisel or the working the edge of a card scraper), that can plow furrows into your water stone(s). The Glass Stones have a much harder matrix that most water stones I’ve used, and I find they do a better job of withstanding these focused pressure situations, without leaving deep depressions in the stones. Ok, back to the skiving knife… I visually check the knife’s cutting edge after each pass on the water stone, so I don’t waste my time, the water stone or the knife’s steel, and continue until there are no remaining chips on the blade’s edge (not a cutting edge at this point, as this process creates a flat at the edge) of the skiving knife. You may be wondering why I would use this technique, rather than working the bevel as you normally do when sharpening. I find this technique to be much faster and very reliable.

 

The chipping is all removed, and you can also see some of the paths this took on the Shapton Glass Stone in the background.

The chipping is all removed, and you can also see some of the paths this took on the Shapton Glass Stone in the background.

 

Now that the chipping is removed, its time to work the bevel on the 1000-grit, until the created flat at the tip is gone. This will prepare it to be a very sharp blade! This skiving knife has an amazingly acute honing angle, and the handle can get in the way of some honing guides, when trying to work at this low an angle. I decided to use my Kell honing guide, as it could hold the blade for this type angle, even though I found it was just barely able to retain it. What I mean regarding retaining the blade, is the blade would try to pivot ever so slightly during use, even though I had applied recommended pressure with the Kell honing guide. It turns out the back section of the skiving blade has a little taper to it, rather than two parallel edges. I found I had to put strong finger pressure down onto the rear part of the blade, while I was moving the Kell guide and blade up and down the water stones, which kept the blade static. One way to determine if you have actually removed enough steel, so that the back and bevel meet in the perfect “zero radius”, is to hold the blade with the cutting tip facing up towards some lights. If you can see any reflected light from the tip (not the back or the bevel) then you still have a flat on the tip and should continue to remove steel from the bevel. When you reach the point where there is no longer any light reflected back from the cutting tip (and you can feel a small burr all along the edge, from the back of the blade), it is time to shift to your finishing water stone, which should be at least an 8000-grit or higher. I prefer to use my 1000-grit water stone to remove the burr from the back of the blade, as it only takes a couple of swipes, but it really depends on the situation. Now on to the finishing stone, for both the bevel side and then the back.

 

Here I've just finished sharpening the skiving knife on the Norton 8000-grit water stone, and the Kell honing guide is seen to the left of the stone.

Here I’ve just finished sharpening the skiving knife on the Norton 8000-grit water stone, and the Kell honing guide is seen to the left of the stone.

 

You should be left with an amazingly sharp tool! I tested my skiving knife on a piece of leather, and it cut through it like it was going through soft butter. This is a wonderful tool that is back in business!

 

Thank you for reading the article and please let me know if you have any questions or suggestions.

 

Lee Laird

LeeLairdWoodworking@gmail.com

@LeeLairdWoodworking – Instagram

How to get a great finish

Posted by is9582 on October 2, 2016 with No Commentsas , , , , , , , , , , , , , , ,

I was recently working on one of my hand-made knives, and while finishing my curly-maple handle, I remembered a technique I’d use on some of my smaller wooden products that I don’t think I ever wrote about before. I decided it would be something good to share with my readers, beyond the aspect of it truly working, but it may also push some to start thinking outside the box a bit more. Anyways, lets get into it.

The handles I use on my knives may be of different types of wood, but I usually go with the same finish on them all, which is Tru-Oil by Birchwood Casey. Ok, if you’ve read my other articles, you already know that, but I’m just filling in the blanks for those who haven’t read any of my previous writings. As with most finishes, you apply a thin coat, wait for it to dry,  lightly sand and wipe the residue off. Basically repeating this process until you get the desired results. I follow the basic design of this, but will give a bit more specific information regarding what I’m using that helps get a better final surface.

In between the first two coats, I use some 400-grit paper to just very lightly touch the surface, removing any nibs or roughness and then wiping away any residue. Just before my final coat, I use a foam backed sanding sheet that is rated 1200-1500 (their specs, not mine), and again just almost letting gravity apply the downward force on the wood, as I’m not trying to do anything but smooth anything that is out of line.

 

Knife with curly maple handle clamped in vise, waiting for the finish to cure, before burnishing.

Knife with curly maple handle clamped in vise, waiting for the finish to cure, before burnishing.

 

After the last coat is applied, I make sure to let it sit long enough to really totally dry, which can be 24 hours or even slightly longer. On an inconspicuous spot, I just lightly touch a finger. If it has any feel of stickiness or my finger doesn’t slip like its on glass, I leave it until this occurs. After the finish is completely dry, I shift to something that might seem strange; a Viva paper towel! And no this isn’t just to wipe some residue. I know many of us don’t look at paper towels like they are a type of sandpaper, but they do have some graininess to them (Viva just happens to be our paper towel of choice, but other may work as well, but may not be quite as fine a grain), and one time long ago, I ran out of some crazy-fine sandpaper I’d been using. On a whim, I decided to give these paper towels a shot. I find I get the best results if I apply a bit of pressure and move back and forth quickly. Basically starting to burnish the finish. After I’ve done this to all sections of the knife’s handle, I go one step further. I use a small section of a thick leather that is somewhat soft, but not really what I would call buttery. Using the smooth side of the leather, I use exactly the same routine as I did with the paper towel. This provides a nice burnish to the handle’s surface, which just feels so good in the hands.

Since the burnishing heats up the finish during the process, I again clamp the knife (via the blade) for another 24 hours, to let the finish harden again. This leaves a handle that is super smooth, but unlike some waxes, doesn’t seem to want to slip out of your grip.

 

Curly Maple knife with it's belly up, showing the level of finish. White leather and folded Viva paper towel are in lower right of photo.

Curly Maple knife with it’s belly up, showing the level of finish. White leather and folded Viva paper towel are in lower right of photo.

 

Curly Maple knife with belly facing down, again with the burnishing tools in lower right of photo.

Curly Maple knife with belly facing down, again with the burnishing tools in lower right of photo.

 

Curly Maple knife along side one in Cherry and one in Claro Walnut. Curly Maple is the only one of the three on which I used the paper towel and leather.

Curly Maple knife along side one in Cherry and one in Claro Walnut. Curly Maple is the only one of the three on which I used the paper towel and leather.

 

If you are working on a smallish wooden project, like a knife handle, or even a little box, you might want to give this a try. You might just amaze your friends/family/customers regarding how “smooth” it feels. Even if you aren’t trying to get the extra response, it’s cool to use a couple of everyday type items to increase the touch-factor of your projects.

I hope you enjoyed this article and may find it useful. Please let me know if you have any questions or comments.

 

Lee Laird

@LeeLairdWoodworking – InstaGram

@LeeLairdWW – Twitter

Leather – Edge Burnishing

Posted by is9582 on May 23, 2016 with No Commentsas , , , , , , , , , , ,

For those that follow me on my other social media, I mentioned I’d write an article describing how I am burnishing the edges of my leather projects, as it is relatively simple and doesn’t require much “elbow grease”! So let’s get after it and I hope this may make it easier for anyone that is […]

Made a new knife

Posted by is9582 on May 14, 2016 with No Commentsas , , , , , , , , , , , , , , , ,

I was brought up around all sorts of crafts and the outdoors. Woodworking and leather crafting seemed to be interwoven into my genes, but really didn’t have much in the way of knife making, although my dad did make a knife or two in his younger days. I’ve seen some of my buddies making wooden […]

Leather Chisel Pliers – my way

Posted by is9582 on April 18, 2016 with No Commentsas , , , , , , ,

I recently got a pair of Hand Chisel Pliers (mentioned in my previous post here) from my local Tandy store, as I was experiencing some negative issues when trying to pierce two or more layers of leather, from one side. This tool looks like it would be one of the most simple tools to use, […]