Japanese Smoothing Plane

A smoothing plane is one that makes nice fine smooth surfaces on wood.  They usually have a reasonably wide profile, so that side to side, they are quite stable on the surface being planed.  They also usually have a slight curve upward at the edges of the plane so that they leave a gentle edge to their cut.  A smoother can take a fine smooth shaving off of a nice section of wood, and leave a mirror smooth surface behind.

Here is a fairly nice Japanese Smoothing Plane in a leather wrapper.

The leather wrapping is to protect it from quick changes in moisture.  Since the mouth of the plane has a lot of exposed endgrain, it is quite possible for the most critical areas to expand or contract quickly and cause the wood to split.   This is the Japanese method of reducing damage to the plane due to humidity.

Here are the tools I use to adjust and tune the plane, a small mallet to adjust the blade position and a strop to hone the plane blade.

Here is the smoother itself;

To remove the blade I tap at the back of the plane, like this;

I would normally hold the plane in one hand, with a finger on the blade so it won’t fly free when loose.  My fingers would not be  anywhere near the cutting edge of the plane.  In this case, I am holding the camera with one hand, so the picture is not complete.

When you strike the back of the plane, it moves forward and down.  The inertia of the heavy metal blade resists movement so for a moment the wood moves down and the blade stays in the same place.  This has the effect of driving the blade slightly back.  With repeat strikes, the blade will come free.

Here is the smoother dismantled into it’s three parts, the blade, the chipbreaker and the body;

Here I am stropping the flat of the blade;

You can see the change in the steel at the edge.  Japanese plane blades are made by sandwiching a layer of really hard steel, for the edge, to a layer of softer steel for the body.

Here is the flat of the blade after it has been stropped.

The Japanese plane blades have a depression in the back, so all you have to sharpen is the edge part really.

To strop the edge, first I place the blade against the strop like this;

Then I rock it forward and hold it with the bevel secure and flat against the strop.

I will also be lightly stropping the tips of my fingers with this grip.  The blade is moved side to side.  This gives me a good level and controlled stroke.  It also will tend to give me a slight curve upward at the edges of the blade no matter how careful I am.  This is a good thing for a smoother.

Here I am stropping the Chip breaker as well.

I want it to be able to fit flush to the edge of the blade, with no gap.  For soft wood, I will have the edge of the chipbreaker back about a 32nd of an inch from the edge of the blade.  With harder or more difficult grain I will reduce this gap.

Different chip breaker positions will give different types of chips.

When using a plane, often chips will collect in the mouth.  Here is how I clear them;

I put my palm at the back of the plane sole and slide it forward.

If I go the other way, I will cut myself.  This blade is so outrageously sharp, that I must always be aware and careful when I work with it.

A Smoothing plane can take rough wood and make it smooth quickly,

Wood grain is important to observe.

If the grain is rising out of the wood like this, ///////  then a plane going this way –> will work pretty well.

If the grain is rising out of the wood like this, \\\\\\\ then a plane going this way –>will dig in and make a mess.

Like this,

These ripped up spots of wood mean that a lot of careful work will be needed and the depth of the tear out will have to be removed from the surface to make it smooth.  So using a smoother requires observing the grain and not going into it.

Here is a real terror for a smoother,

At the knot, the wood rises to go with the original branch.  You may be able to plane well to the knot, but not past it.   An expert may be able to deal with this.  By moving the chipbreaker right to the edge of the blade, it might be able to handle this.  Personally I would use a scraper here.

The smoother was not the right choice for this task.


4 comments to Japanese Smoothing Plane

  • Good overview of this type of plane. Curly grain is tough to deal with and so I liked how you are showing in photographs the effect of planing into the grain. I just finished a video series with Japanese hand plane expert Craig Vandal Stevens. Craig makes it look easy, but as you are aware, your skill is key in using this tool. But what fun, yes? Thanks for all you articles. Keith (www.woodtreks.com)

  • Skip J.

    What Keith said! Hello Keith – nice website! Congrats…

    And Bob, you have also raised the issue of knots. I nicked and dulled a lot of plane blades before working up a strategy for knots. I started using thick blade jacks to take the knots down first, now I use a very thick blade scrub to cut’em down below the surface level. Then I just smooth the surrounding wood down almost, but not quite to the knot level. Then scrape it and it’s flat as a pancake!

    Of course, I prefer to cut’em out and glue up a panel without knots – but it sure uses up a lot of expensive wood!


  • I love your site Keith, it is clear that you have a great deal of understanding of wood, and of cinematography. The videos are clear and are focusing on what is critical. Great work there!

    Dealing with the tough wood, can be the most rewarding. It is often dramatic and richly shaded. I tend to take too much time on it out of fear.

    I decided to be bold here and show plane use done plainly. It really hurt to rip up such lovely wood, but if this sacrifice helps someone else to avoid such errors, know how to get around them, and not give up on hand tools, then this was well worth doing.


  • john pendergast

    Most Japanese planes are made for softwoods(by their angle). Westerners who smoothplane mostly hardwoods need to look for plane made for hardwoods (angle). It should indicate this in the ad. You can use soft for hard but you may be dissapointed in the results.

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