Kanna Techniques

My endêver to gain an understanding of the setup & use Japanese Kanna is ongoing. I would love to incorporate kannas as part of my tool kit however they continue to elude me.

NeilS was kind enough to donate a 60mm wide Kanna towards my studies. The blade was in bad condition and the Dai was badly warped.

I flattened the sole, glued in some thick paper to tighten up the bed, took my time setting up a hollows. Testing along & across the bed.

I set the bed up with two contact points.

I took my time sharpening the blade, I fitted the backing iron. So no light shun through between the ura and the backing iron and made sure that it did not rock.

Now I can easily take a heavy 0.5mm full width shaving in rock maple, red oak & NZ beech. However beyond this I have a myriad of problems:

Problem 01

As I ease the iron back taking finer and finer shavings it becomes progressively harder to take long continues full width shavings.

The shavings break up, I get super fine shavings, thin enough to read news print through. However I cannot get the bloody shaving to hold together, think of tissue paper confetti. I tend to use the plane like sandpaper working in spots. I tend to get a shaving in one section then nothing in another part of the board. No long shavings.

Problem 02

The other problem I am having is how to hold the kanna, the kanna is extremely sensitive. Even the lightest shift in hand pressure can adjust the depth of cut, through the stroke. I have tried placing my hand in the middle, to the right, forward and backwards on the dai but with no consistent results.

Problem 03

The other problem I have is toward the end of the stroke. As the two front contact points pass beyond the end of the board the kanna drops and I get an incomplete cut and a ruff finish.

Problem 04

Squaring up stock is a problem. I watched a few videos as it seems that the Japanese make extensive use of the shooting board to shoot the edge and end of boards however how they work with say a 50 x 50 square piece I do not know.

On the positive side the surface finish is glass like, giving the wood a burnished appearance. I really feel & fear that I would need to study at the feet of a master to get this tool.

Hi Thumbsucker,

My $0.02 worth.

Problem 01 - Where did you pack the paper? Make sure the paper is holding the blade at the side grooves and not in the middle of the blade. Make sure the area immediately behind the blade is recessed and check it when the blade is tapped down in place (as close as you can get it to operating position without actually protruding) The fact that you have two contact points means you probably have already done this. Next, I'd suggest you tape some sandpaper to a VERY flat surface and ensure the sole is flat, especially immediately in front of the blade.

Problem 02 - See 01 above. If you can get varying depth of cut with hand pressure it sounds as if you could have a sole flatness issue (area in front of the blade not touching the stock, or area behind the blade not relieved). Regarding where to apply pressure: with a two point contact you need to have downward pressure between the two points, which means in front of the blade. With one point at the front and one in the middle at the blade, there can be a tendency to rock back onto the recessed rear of the dai.

Problem 03 - To begin with you are probably better to set it up with 3 point contact, so the rear is supported until the blade reaches the end of the pass.

Problem 04 - After 25 years of playing around with kanna I still find it more difficult to produce square flat boards than with western planes. Practice, practice, practice.

By the way, description of front and the back of the kanna is opposite to Odate (who describes the front as pointing away from you and the rear as pointing towards you). My descriptions above are in relation to the direction of travel. The front moves towards you and the rear faces away.

Gadge

Tune in Folks - I will post photos tomorrow. Making progress :D thanks to Gadge.

My exploration of the kanna continues.


Using Gadge advice I flattened the sole of the Dai on some 16mm float glass. I then marked 6mm line at the heal, toe and in front of the mouth. Then very systematically I used a large plane blade to scrape out to hollows, using a good quality 150mm rulers I tested the hollow. Advice this is the most critical step, I kind of just did it in the past, but it needs your undivided attention. Testing all angles across the sole. It may look good all over but all it takes one place that led to my opening post.

https://www.woodworkforums.com/attach...1&d=1470537230 https://www.woodworkforums.com/attach...1&d=1470537294 https://www.woodworkforums.com/attach...1&d=1470537294 https://www.woodworkforums.com/attach...1&d=1470537294


The blade came from NeilS it was badly pitted and rusted, however with some phosphoric acid I ws able to remove the worst of the rust. However heavy pitting can be seen in the ura. The era is also misshapen from its previous owner.

https://www.woodworkforums.com/attach...1&d=1470537383

I had a problem with the blade which was at the very same point (where the lamination bulges in thickness) a chip would form after only a few minutes of use. A defect in the forging I suspect. So I decided to increase the bevel angle to 34º.

https://www.woodworkforums.com/attach...1&d=1470537294

However this caused another problem because the bed of the Dai is sow low, the trailing end of the bevel would contact the wood before the tip on a fine shavings. So I carefully took the blade to the grinder and ground the back away, so now the leading edge of the bevel is 34º but the trailing end is below 30º.

Attachment 389897

I also did the usual refinements to the cap iron. Honing a 45º micro bevel and flattening the back.

https://www.woodworkforums.com/attach...1&d=1470537447 https://www.woodworkforums.com/attach...1&d=1470537447

Now for shavings. I tried to use a variety of woods I have at hand. Here are some examples of the shavings and the surface finish.

This is Western Red Cedar, one of the most difficult woods in my experience to plane, almost all planes leaves the surface furry, the higher the bedding angle the worse the surface finish. Since Western Red Cedar is so soft the wood crumbles, tumbles and deforms before the cutter. However the kanna handle it admirable, while not perfect is silky to the touch and glossy in the light.

Attachment 389900 Attachment 389899 Attachment 389898Attachment 389901

The next set is from Fiddleback Red Oak, its kind of the opposite to the Western Red Cedar. Much harder, very coarse and the fiddleback often challenges my Lie-Nielsen No.6. However the kanna had no problem with it. Again the kanna leaves a lovely sheen and a defect free surface.

Attachment 389906Attachment 389905Attachment 389904Attachment 389903Attachment 389902

I tried is out on a bunch of other timbers, a piece of amazingly extremely heavily fiddleback NZ Beach, it works as long as the kanna is tuned perfectly. Blackwood was easy so was VicAsh. American Cheery & Black Walnut was again no challenge and amazing. I will post more photos in a few days if people are interested. I also want to find some Jarrah & Red Gum while I do not use these timbers I think the kanna could tame them. The Japanese do use ebony's at time and they are planed with a kanna.

Problems - Any thoughts?

• I feel my free hand sharpening is not up to scratch. While I can now pull full width shavings often there are tears in the shavings where microscopic defects in the bevel do not allow me to take a perfect shaving. This could also be from the blade itself not being the highest standard. But it is also caused by the wood itself. Some timbers hold together better then others.
• It takes me forever 20 minutes to sharpen a blade. Again experience.
• Today the weather changed and its sunny and the air dried out a little more today then it has been for the last few days. The kanna was amazing yesterday but today it was a struggled. I would need to touch up the Dai but it would take me hours I think. I also feel that the Dai being Masame. 3 sides straight/quarter cut is not ideal for me climate, and I would have a more stable Dai if it was cut Oi-masame Corner/rift cut. How do I go about making everyday adjustments to the Dai to cope with the humidity? I am thinking maybe to give it a light lapping on the float glass to ensure the three running surfaces are co-planer. Then touching up any burnished areas in the hollow with a card scraper?
• I am uncertain about how much crown to hone into the blade. Up to now I have honed a perfectly flat bevel, however I need to set the blade on a very fine cut to avoid the train track effect. I am leaning toward adding a subtle crown, however this will effetely narrow the cutting width of my blade.

Why?

Now people would ask why to I even bother with these bloody things. The answer is simple, when I can get them to work and it gets easier with time, effort and experience, the surface finish I can get from a kanna is far beyond anything a Western plane can offer. In comparison a Western plane leaves the surface dull & blotchy requiring sanding to even out the timbers appearance. With a kanna there is a objectively burnish planed surface finish.

My plan it to get a handle on the kanna enough to use it apply the final finishing cuts on a Japanese joinery project I am currently undertaking, no / nil / zero sanding.

A less objective reason is that a kanna feels intimate there is so little between me and the material. No dials, no threads, no knobs, just a hunk of steel and a block of wood. It feels so lovely its like that feeling you had the first time you got a plane to sing for you.

Future

I want to purchase another kanna a narrow 65mm at the widest and a good Dai to go with it. I am looking at Tsunesaburo or Kikuhiromaru, I am leaning towards Kikuhiromaru just because I have some one his chisels and they are excellent. However Kikuhiromaru is far more costly then Kikuhiromaru. I would also opt for a 42º bedding angle rather then the standard 38º.

Let the LEARNING continue

Hi Thumbsucker,

A couple of suggestions re micro bevel on chip breaker and crown on cutting edge of blade.

If you haven't seen this guy, take a look at about 8 minutes in where he talks about the crown on the edge. He suggests to leave about 80% of the edge straight and then curve away from there. At about 10 minutes in he talks about the micro bevel on the chip breaker. He suggests an angle of around 80 degrees and around 1 mm high. He's difficult to understand but his advice is to tap the chip breaker down until the blade edge just disappears behind the edge of the chip breaker as seen from the top of the dai. At that point the chip breaker is only about 0.3 to 0.5 from the cutting edge and produces those lovely straight shaving that look like magic. When you start to produce those you'll think you are a master. I can spend a lot time making little pieces of wood out of big pieces, just to watch those shaving come out.

https://www.youtube.com/watch?v=bT5qLzbidRs

By the way, all his videos are worth watching.

Regards,
Gadge

Hi Gadge - Thanks for the video I will go through them.

I will have another go tomorrow at sharpening the blade with a crown.

I will also redo the backing iron bevel.

I have been bringing the cap iron as close to the edge as I can. I ground the ears a touch narrower then the cap iron so I can see just how far down I have the cap iron.