We just entered our second state of emergency here in Tokyo, meaning there’s still no where to go and not a whole lot to do outside our home. Honestly it feels no different than before the state of emergency. My wife has been working from home full-time for almost a year now, and aside from buying groceries we really don’t venture out much. Like so many people these days, being at home has forced us to come up with more creative ways to keep busy. So my wife started sewing and making clothes, and I’ve been sharpening planes… and filling our apartment with plane shavings.
With that in mind, I thought I’d share a quick video and a few pictures again showing how I’ve been sharpening lately, using the double-bevel technique. I’m still amazed by the results this technique has been giving me. I can consistently get a really sharp edge, and fast. During work it’s a method that really pays off.
Eliminating Plane Marks
In the video I also show the technique I learned from my friend Yama-san for eliminating plane marks. If you plane a wide, flat board with a straight edge on your plane you will inevitably end up with little ridges between passes of the plane. People say you can perfectly plane a board with no marks using a flat blade. It may be possible but I’ve never seen it done, and it clearly requires an incredible amount of skill. Most carpenters solve the problem by cambering the blade. Cambering the blade involves sharpening the edge into a slightly curved shape. The result is a plane shaving that tapers to nothing on each side, eliminating any steps. Cambering can work just fine, but personally I find it to be kind of cumbersome and slow. Cambering also changes the shape of the blade more, making it slightly more of a pain to re-sharpen back to a flat edge. The technique I learned from Yama-san involves easing back the very corners of the blade, ever so slightly with a finish stone. I like the technique a lot because it’s fast, easy to repeat in subsequent sharpening sessions, and it doesn’t change the shape of the blade very much.
Here is the blade from the video after sharpening with the double bevel technique and easing the corners using Yama-san’s method. The change to the corners is almost imperceptible from a distance. (scroll down for some close-ups)
Sharpening Method Explained
I sharpened this time starting with a 1000 grit Hibiki stone. Working the regular bevel I’m able to grind off the old double bevel pretty quickly. Then I move on to a 8000 King finish stone and start polishing the double bevel. I hit the ura side once to start taking off any burr. After that I worked each corner of the blade in a circular motion to ease back the corners. You need to raise the blade up ever so slightly so that just the corner is hitting the stone. I’m not sure if working the corner in a circular motion is all that necessary, but it’s what Yama-san does, so I’ve been imitating that. Finally I hit the double bevel again on a super-fine 12000 grit Naniwa stone. Each time I alternate back and forth between the double bevel and ura side of the blade. Lately I’ve been hitting the ura and double bevel around 3 times on the 12000 stone. I found that if I use pretty firm force the first time, it really eliminates any jaggedness in the edge. On the second pass I lighten up my pressure and work to remove bits of burr from the edge. The last pass on the double bevel and ura side I hardly use any pressure.
In the picture below the black line at the edge is the double bevel.
In the following two images below I tried to capture the extent of the eased corner. Both pictures are of the same blade after sharpening as described above and in the video. In the first picture I angled the blade so that the light was reflecting off the eased corner. In the next picture you can see the black line that is the double bevel. Where it disappears is where it meets the eased corner. The small amount that the corner has been eased back is all it takes to eliminate plane marks during finish planing. Pretty simple and quick.
Thanks for reading and happy planing.
-Jon
Jon I don’t see the video link…
I must say you and Kay are very talented and patient people. Fun to be around!
Oops, for some reason if you are reading from email the video link doesn’t show up. You have to actually view the post on my website, which you can do if you click the post title/link. I’ll try to figure that problem out.
Thanks!
Ok thanks!
Thank you for the pictures and technique description. I’m sharpening kanna blades today and this provides a good guide to the procedure and what to look for. Stay safe, things are bad out there for now. I really enjoy your posts, they’re so helpful.
That’s great to hear, thank you!
Hi Jon – just want to say this was a great series to read. Really refreshing to hear about techniques that don’t get a lot of attention in North America, and a focus on how to get work done faster, instead of how to plane the thinnest shaving. I really enjoyed it – hope you’re doing well!
Thanks Spencer!
Jon, Do you have a preference/ recommendation for the flattening stone you are using? I am looking forward to trying out your system. Thanks so much for all your recommendations!
Hey Mike, I mainly use atoma 400 grit diamond stones for lapping my water stones. For the price they are really good lapping plates. I’ve heard some people complain that the 10mm thick aluminum plate they come with may not be flat, but I’ve personally never had any problems. I’ve gone through a handful of them over the past few years and they’ve all been fine. The 400 grit stone may feel pretty course at first but pretty quickly mellows out, and it cuts much faster than the finer grit versions. I usually use just one lapping plate for all my stones and only use it for lapping stones. If you sharpen tools on the lapping plate the diamonds tend to wear unevenly and you can get uneven results when lapping your stones.
Hope you have good results with the double bevel method.