Kanna - Dai Prep

[Brian Holcombe]

In Preparing my Hikouki kanna, I've taken steps to prepare the sole and documented those steps here.


https://brianholcombewoodworker.com/...anna-dai-prep/


I will be first using the kanna to compete at Mokuchi, then resuming the conversion into Hikouki kanna.

[Pat Barry]

Very interesting Brian. I'm curious about the reason for not having a perfectly flat sole though. Why are you striving for a 4 mil clearance right behind the blade? Also, what is this competition you mention? Something like the videos we've seen of guys making one continuous 8 foot long transparent shaving?

[Brian Holcombe]

Thanks Pat!

My understanding is that there are multiple reasons for the hollow in the sole. Theory being that having a small strip allows localized pressure which helps to heat and stretch the wood that is about to be cut.

Without clearance after the blade the dai will lift the blade off of the work. Installing a blade into the dai puts pressure on the dai just under the blade and that pressure bulges the wood slightly. Because the dai cannot be flattened with the blade installed the alternative is to make clearance.

Yes, the competition is exactly that, but smaller scale.

[Mike Holbrook]

Nice Brian! Good luck! I like all your videos. You just need more comments on the fine points regarding the fashion statements. You know how Stanley lives for those.

I could lend you a German Shepherd who could dispose of those shavings just as fast as you can make them, but maybe that would be counter productive, never mind (thats a Gilda Radner never mind, checking out your ancient Saturday Night Live trivial knowledge level).

[Brian Holcombe]

Haha! Indeed, wait until the planing robe is revealed!

That brings up a great mental image of a dog eating shavings flying out of the plane. I go only as far back as the Samurai Delicatessen.

[Mark Gibney]

Beautiful, and thanks for taking the time, this might be the clearest how-to on this I've read.

I have some cheap kanna sitting in a drawer that I now feel I'm not guaranteed to ruin when I get round to fettling them. See? I bet kanna are not fettled, are they? I'm off to a bad start, dagnabbit!

[Brian Holcombe]

Thanks Mark, I appreciate the comment. I wanted it to be especially clear in areas that I found no one else really covered, or covered somewhat quickly, that I remained confused upon for the first setup but on the next few became more clear on.

On my first dai setup I opened the mouth, later figuring out that it was the wear that needed work, not the mouth, and then repairing that by making an insert.

The plus side is that pretty much everything is repairable, but the repairs are often daunting in their own right though certainly not impossible to make.

I have plans to build a Naga-dai Kanna coming up very soon, cutting it out of rift sawn American beech, and so I'll likely detail that process as well in a few weeks.

[Stewie Simpson]

hikouki kanna, or a plane with runners. http://www.daedtoolworks.com/tooling-for-shoji/

Brian; I did a quick search on the internet, and I now understand what you mean.

Stewie;

[Brian Holcombe]

Excellent! This sole treatment applies to finish planes, so it's fairly broad based. In September I plan to make the conversion into Hikouki kanna and it will be specifically geared toward that.

[Patrick Chase]

Wow, that is one excellent witeup. Nicely done, Brian!

[Patrick Chase]

hikouki kanna, or a plane with runners. http://www.daedtoolworks.com/tooling-for-shoji/

Brian; I did a quick search on the internet, and I now understand what you mean.

Stewie;

Stupid question: Isn't that spring-loaded cylinder doohickey just compensating for the relief in the Kanna's sole?

Put another way, would you need that if the Kanna were prepared with a flat toe instead of being relieved ahead of the mouth?

[Brian Holcombe]

Thank you!

Not sure, as I've not tried it both ways.

I have tried planing thin material with fully flat planes and the material will bind and then bow. So I imagine it is a combination of all things which brings success, the extremely flat track along with the plane on runners and the spring loaded pressure bar which is likely especially critical in the last cuts finally combined with a relief at all areas not needed.

It's been my experience that applying much pressure will bow the material, so I presume the design is made to allow downward pressure while eliminating as much force as possible in the direction of the plane travel.

[Stanley Covington]

The purpose of the goro ganna, or hikouki kanna as Brian calls it, is to gang thickness plane and finish plane the thin slats of wood called "kumiko" used for making shoji and other fine latticework. The purpose of the spacers attached to the sole, or the runners on the sides, is to set the final thickness of the kumiko.

Regarding the pressure bar Brian will add to his plane later, please note that the kumiko used in shoji and kumikozaiku are lightweight, thin and flimsy, and the cutting force and angle of the blade tend to pull the kumiko up against the plane's sole causing them to float above the planing beam or workbench top with the result that the kumiko get planed thinner than intended. This happens regardless of the amount of downward pressure the craftsman applies to the plane since the spacers/rails keep the sole at a fixed height above the work surface. The spring-loaded pressure bar keeps the kumiko from lifting up, and helps ensure the cutting action stops when the intended thickness is reached.

The following link shows one version of the hikouki plane. I was trained to disdain this version, and it does have some fundamental flaws, but it does show the pressure bar and side skids. The page also shows a number of specialty planes for doing kumiko work and kumikozaiku. A very expensive rabbit hole indeed nowadays.

http://daikuhamono.sakura.ne.jp/kannairoiro.htm

There are power tools called Super Surfacers (fixed knife planers), etc. that can do the same job as this handplane, and many professional shops in Japan will have such a tool (horribly expensive), but short of having such a tool, the goro handplane is the only way to get the right finish on the wood's surface, since kumiko are almost always left bare, unfinished wood. Sandpaper is absolutely unacceptable.




Here is a link to a very cool video of the Marunaka Mecca. https://www.youtube.com/watch?v=eaCl...ature=youtu.be

I tumbled down this rabbit hole a long ago, and have never having climbed out, so I look forward to reading more of Brian's excellent adventures.

Stan

[Brian Holcombe]

Thank you Stan! Great post!

In addition it should help me with some areas of cabinet work. When I make small and fine parts by hand they become difficult to thickness plane which then makes the process time consuming. These small efficiencies add up when working by hand.

My main goal in doing this is to begin building shoji. In effort to further improve my woodworking I feel that shoji and kumiko will add new depth, as the process when done at a high level is both fast and accurate while producing a lightweight and strong product.

Super surfacers are awesome. If you guys reading along have wondered, this is what the Kato and Kawai video was geared toward studying. If there were ever a machine for me (budget aside) they would be it.

[Patrick Chase]

There are power tools called Super Surfacers (fixed knife planers), etc. that can do the same job as this handplane, and many professional shops in Japan will have such a tool (horribly expensive)

I heard somewhere that Super Surfacers use cap irons to control tearout.

Great post as always, thanks for the explanation. That makes sense - if the workpiece tends to be drawn off of the bench by the plane then even a flat toe wouldn't prevent that. You need something that applies a constant downward force (i.e. the spring-loaded bar) rather than constant interference (flat sole).