Saturday, September 20, 2014

The wonders of using a high angle Japanese plane



Being half out of my mind, suffering from my first cold of the school year (a condition that every parent well knows), I can't seem to muster much enthusiasm for house related work.


I am still working on the deck.


The skewed blade of a kiwa-ganna is effectively a very low angle plane, perfect for planing endgrain. The Port Orford cedar is so nice to work with, I just can't restrain myself. The deck surface will remain un-planed.



Another kanna that has proven very useful throughout this project has been this higher pitch kanna, a 47 1/2° bed angle vs the more common 38°.




This EXTREMELY generous gift has helped me tame some of the more unruly grained sections of this occasionally fussy wood.


POCedar is a wonderful wood to work, but the stuff that I have is of lower quality (really inexpensive, though!), and has plenty of flat grain and quilted figure. It's beautiful, but will tear-out if you look at it funny.


Dave's kanna is virtually brand new, in fact it would surprise me if it has ever been used before. It is of good quality, sakura hiromasa forged by Kouichi Kobayashi, and is currently available through Japan Woodworker . The blade is made of blue steel, forge welded to good soft wrought iron ren-tetsu. The back blade is laminated. The oil soaked dai is fine grained and straight.



This is my first new kanna. Thanks Dave, this is going to be interesting!




In the western tradition, difficult figured woods are surfaced using a special plane with a steeper bed angle. While the standard western bench plane will have a typical bed angle of 45° (common), a higher pitch plane for figured wood will have a bed angle of 50°(York), 55°( middle), 60°( half). Steeper than that, and I call them scrapers, but I'm no pro.

It would seem that the addition of a few simple degrees will make a plane perform wonders, but why don't more Japanese planes come with steeper pitches?Japanese planes are cut almost exclusively at a 38° bed angle, and even though this would be considered a "low" angle plane to western eyes (and therefore completely unsuitable for use on hardwoods), skilled users are able to get them to work incredibly well, even on the hardest of figured woods. I have some problems, particularly with this POCedar, but also with rowed wood, burls, quilted...... Jeez, most anything gives me trouble sooner or later!

High angle kanna are made, however, mostly for the american market. I have had the intention of making one for a while now, but when you haven't used something before, you naturally question it's utility. That's where Dave came to the rescue. He knew that I had been wanting one of these higher pitch planes for a while, and being the generous guy that he is..... (Actually, Dave doesn't know me from Adam, only knowing that I've obviously got some serious Japanese tool issues that I'm sorting out, haha!)


I am going to write this under the assumption that this IS a brand new kanna, and is representative of what anyone would receive, if they bought one from the same retail store. Japanese tools are seldom ready to go, and almost always need some work to prepare them for use. This is normal stuff and is all part of the fun.


 Any comments that seem to be even HINTING at anything less than absolute wonder at Dave's generosity should be written off as a lack of talented authorship skills. I love this plane, and it is a fantastic gift!






The plane came to me commendably sharp, so I was able to use it immediately. If this kanna were a car, it would have that "new-car-smell". No dents, dings..... Nothing. Did I mention that it's sharp, too?




While the blade is perfectly sharp, the fit of the blade is a little loose and uneven side-to-side. I was able to set the blade well enough to be used, but it took a LOT of fiddling, and was too loose to maintain its setting, tending to self-advance, and cut too deeply.

This is a perfect example of how a person, new to the peculiarities of what to expect from new Japanese tools, might order a plane/chisel/whatever, and be, um..... less than satisfied. As it came, this plane would be a BUGGER for a kanna novice! And, to be clear, this is about what you would get if you bought a tool "ready-to-go". A tool intended for the professional market would require even more work! I'm no pro, but I DO know that I like my kanna to be a particular way, and a factory can't provide that.

A pro will set the tool for the conditions. There is no "one-size-fits-all". This kanna was probably perfect when it left Japan, but by now the wooden body has moved a bit, the blade may have relaxed it's shape some, whatever. Believe it or not, this is part of the attraction (for me at least). It gets me more involved, more integrated, in what I am doing.


A couple of light taps with my little wooden mallet is enough to set the blade far deeper than you would ever want.

Sighting down the underside of the kanna body (upside down), you can see the blade protruding unevenly on one side.

Because the blade bed fits unevenly (and I'm in a hurry to use this plane!), I choose expedience and shim the blade using tape.


I put a small scrap of thin, house wrap tape in one corner, then a larger piece over the top.


Even these two, very thin pieces of tape prove too thick..... And too slippery.


Blue making tape to the rescue.


One piece is fine for now. It really doesn't take much. I prefer a paper shim over either tape or a thin wooden shim, but this kanna only needs a little bit of assistance (and I'm excited to try this guy out!).

A loose blade is easy to remedy. I live on the Oregon coast, but this kanna came to me from Virginia. It's very possible that the blade will fit perfectly in another month or so, and if I had taken more drastic measures........


These tools almost always come with a coating of rust inhibiting lacquer. I don't like the shiny look anymore, and the lacquer feels gummy on the stones, so.....


Lacquer thinner or acetone takes it right off. I still need to strip the chip breaker.




That's better.


The chip breaker is very tight, and will require more extreme measures to fit, so for the time being, I will use this kanna as a single blade plane.


I want to try this kanna on some wood that has been giving me fits. This is a chunk of African mahogany (khaya, perhaps?) a moderately hard wood (about like american red oak) that is often rowed and almost always tears out at least a little bit. In the past, I have had to resort to sanding :'(


The pull is significantly heavier than a traditional lower pitch kanna, but not bad. There is some tear-out, but less than I would normally expect.



Here's another little thing. When I am adjusting a blade and I just want to advance or retract one side of the blade, I often wedge my thumb against the side of the blade while tapping the head of the dau, right at that chamfered corner above my thumb.


This frequently causes the dai to crack, so I give myself a large target to hit. Here is a different kanna, to serve as counterpoint.


I like the clean, crisp look of the traditional kanna dai, but a bit of rounding (or at least a very generous chamfer) doesn't look too odd. I tend to get rather enthusiastic when customizing my kanna, though.



Even taking the lightest cut that I can, I still get a fair bit of tear-out.


 The #1 cause of poor performance is a blade that needs sharpening.


See that bright line at the very edge?

The blade dulled quickly, but remember that I had been using this for a few days on the POCedar. This African mahogany is very abrasive, too.

Another factor that would contribute to premature dulling, is the sharpening angle. Despite being fitted to a high angle body, this blade was still sharpened to the ubiquitous 25-26° angle.



I favor 28° for my normal smoothing planes, so I figured that this high angle kanna can comfortably go up to 35° or so.

I could jump right to 35° if I don't mind losing 3-4mm of blade length, and having to perform ura-dashi immediately. I could also use a guide, and only sharpen the 2-3 mm at the tip, but for now, I only do the minimum.

I favor gradually sneaking up on my target sharpening angle, so holding the blade vertical, I file the end to a flat. I am using my cheap China diamond stones that I have mentioned a time or two.


I want an even line of reflected light, and in this case, end up with a 1 mm thick, blunt edge.


Still on the diamond stones, I gradually lower the blade until the majority of the blade is in contact with the stones surface. This only requires a few minutes effort. By blunting the edge, then concentrating just on the tip, I can raise the sharpening angle by about 1° at each sharpening session. You need to be attentive, though. Gravity and the centered mass of the blade conspire against you. Dropping the angle is easy. Raising it is more difficult.

Raising the angle gradually helps me to better know the blade itself. Each blade is slightly different, and it is entirely possible that this blade might not work well at, say 35°, but be a stellar performer at 32°. If i jump to 35° right from the start, I would have no basis of comparison.



Today, because I am only doing a minimum, I jump from #220 diamond, #1000 king hyper, #5000 rika, then finish on a natural stone of around #8000-#12,000 or so.


This wrought iron likes the natural stone and polishes out nicely. This is a nice looking blade.



The polished blade gives a wonderfully smooth finish to the wood....... and NO tear-out! To get a finish this nice, on tricky wood, using no chip breaker blade? I am amazed!




The shavings show a remarkable lustre.


Shiny shavings =


The wood is glassy smooth and extremely reflective.


This plane has been a revelation for me. I know that a higher pitch plane will handle difficult wood, sure..... But that generally comes at the expense of finish quality. A steeper bed angle translates into a blade that scrapes proportionally more of the wood cells, as opposed to shearing them cleanly. I was expecting a dull surface. This is anything but dull.

The wonderful shine is partly due to the species of wood used. This "mahogany" is harder than pine, and should finish to be more shiny.

The chip breaker/back blade/secondary bladeblade/sub-blade, whatever (I need to just start using the Japanese term, osae-gane) compresses the wood shaving as it is cleaved from the surface being planed. This does effect the finished surface, and typically results in less shine. Single blade kanna are used for the "brightest" shine.

For difficult wood, the osae-gane is a necessary evil. At least that's what I thought. That this plane worked so well, just as a single blade, make me wonder how it will feel when the osae-gane is properly fitted. The pull will be heavier to be sure, but I am feeling optimistic about is capabilities on heavily figured grain. We shall soon see.

Sharpening. If nothing else, this example proves the value of a sharp tool. Dull doesn't cut it.


Thanks Dave, for the wonderful gift. I love it!




2 comments:

  1. You're welcome. That kanna has been sitting here for a few years and I really don't think I would ever touch it because I have more than enough without it. Not really sure why I bought it on eBay back then but it must have been a good deal or something. It looks like you got good results after sharpening. I hope that it works well for you and thanks for all the excellent posts.

    ReplyDelete
  2. It has already helped immensely. Truly.

    My thanks.

    Jason

    ReplyDelete

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