First page of the Shapton archive.

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

Knife making and LeeValley Mini Router Plane

Posted by is9582 on November 22, 2016 with No Commentsas , , , , , , , , , , , , ,

For the majority of the knives I’ve made, I split the handle down the middle (lengthwise) and fit it around the tang of my knife’s blade. On many of my smaller knives I have a hidden tang, so the tang doesn’t show at any point around the handle, except where it extends out the front.

For some of the knives, the tang is fairly narrow, but still strong for the intended type of work. With this size though, it can be a bit limiting as to the tools I can use when evacuating the wood where the tang will fit.

 

Inside surface of a knife's handle scale, with outline of full handle drawn, and the blade's

Inside surface of a knife’s handle scale, with outline of full handle drawn, and the blade’s “mortise” ready for the mini Router Plane.

 

The width of the handle scales (when laid on there side) is also an issue, as one of the tools I’d normally choose would be my Lie-Nielsen No. 71 or my old Stanley No. 71. Even with the closed mouth version that I have, it is very difficult, if not impossible to stay registered on the outer wood, so the small square blade for the No. 271 is of no real use. As for shifting to the No. 271, I really prefer to have a fine screw-adjust, when sneaking up on a final depth.

 

The mini Router Plane below my #71 Closed-Throat Router Plane by Lie-Nielsen.

The mini Router Plane below my #71 Closed-Throat Router Plane by Lie-Nielsen.

 

A couple of years ago a friend of mine showed me a gift he received from his kids, and it was one of the Lee Valley mini planes, which got some chuckles from everyone around. He went on to share that it was truly completely functional, which I know it says on the website, but it was still hard for me to wrap my head around. Ok, shift back to present time, and I decided to take a chance and ordered one of the Lee Valley Mini Router Planes (shown above in the lower portion of the photo), hoping my results might surprise me.

I opened the packaging and my heart sort of sunk. The presentation box this little router plane comes in is so tiny, almost to the point where I was afraid I’d made a mistake. I opened the box and the plane was so amazingly small, but all of the parts worked super smooth. I took the blade out of the plane and took it to my Shapton 1000-grit Glass Stone (as this blade is quite narrow, the Glass series stone is one of the few stones I trust will not create a long dado in the stone in rapid order) and worked the bottom of the blade. This blade is made from A2 steel, and it took a fair amount of time to work so it showed a consistent scratch pattern.

 

Bottom of the mini Router Plane's blade, after the water stones.

Bottom of the mini Router Plane’s blade, after the water stones.

 

Bevel side of the min Router Plane's blade, after the water stones, showing obvious signs it wasn't ground on a flat medium at the factory.

Bevel side of the min Router Plane’s blade, after the water stones, showing obvious signs it wasn’t ground on a flat medium at the factory.

 

This wasn’t because the blade was out of square or warped, just because the steel was so hard! It felt like I was working a super high Rc valued Japanese iron, or something on that magnitude. I followed doing the same on the bevel side of the blade, but since this is such a small blade, I could only make short back and forth movements. All of the sharpening was freehand, as no guides that I have would work with this blade. After both mating surfaces were complete on the 1000-grit, and I had a small burr, I very lightly worked both surfaces on my Norton 8000-grit water stone. This stone is much softer and I was very cautious not to stay in one spot for too long. I brought in my Glass Stone 16000-grit to finish up the blade, and brought both edges to a razor sharpness.

While I had the mini Router Plane apart, I noticed it’s sole still had mill marks from manufacturing, so I put some sandpaper down on my flat granite plate and worked it until all of the milling marks were gone. I applied some wax to the sole, which is what I do to the sole on all of my hand planes, so the friction between the wood and plane is almost nil. There is no good reason to leave the sole unworked, and basically fight against the wood.

 

The base of the mini Router Plane, after I'd already worked it a bit on a flat surface with some sandpaper. I continued until al the mill marks were removed, and then applied some wax to the surface.

The base of the mini Router Plane, after I’d already worked it a bit on the sandpaper. I continued until al the mill marks were removed, and then applied some wax to the surface.

 

After re-assembling the mini router plane, I took it to a knife handle where I’d already cut along the shape of the tang, with an Exacto knife, and removed a fair amount with a very sharp chisel. When I set the mini router plane onto the handle blank, it looked like this might actually work. The size of the little router plane just looked like it was the proper scale for the work needed. I was so pleasantly amazed when I started removing wood, as the blade in the router plane was cutting through the wood like it was butter. And this feeling didn’t stop anytime soon. I finished both inside areas of the handle for this knife blade, and it was still going strong. Part of this is the small cross-section of area it is cutting, but still, the A2 in this blade is really holding its edge like a champ!

I hope you enjoyed the read and perhaps will test the same for yourself. Please let me know if you have any questions or comments.

 

Lee Laird

@LeeLairdWoodworking – IG

@LeeLairdWW – Twitter

Card Scraper preparation – you too can do it

Posted by is9582 on November 11, 2013 with No Commentsas , , , , , , , ,

You can read this article at: http://blog.woodworkingtooltips.com/2013/11/card-scraper-preparation-you-too-can-do-it/ Thanks for checking in! Lee

Sharpening – Do I need to go to 30,000 grit?

Posted by is9582 on March 2, 2012 with No Commentsas , , , , , , , , , , , , , , , ,

Like many of you, I sharpen on a very regular basis. I’ve tried most of the different sharpening media that is presently available, along with some that are not so readily found any longer. I’ll share some of the results, and hopefully answer the title question. When I first got into woodworking, I purchased three […]

Let’s Skate towards Sharpness

Posted by is9582 on February 7, 2012 with No Commentsas , , , , , , , , , , , , ,

I don’t know about everyone else, but even though I have a good sharpening routine, I’m always looking out on the horizon for something potentially better. I’ve either owned or used most of the current, and many of the older sharpening guides/tools, so I’m really looking forward to testing what ultimately is a new concept […]