Think Small: The No. 3 Way to Reduce Tear-out#

Most handplane geeks know that across the Pacific Ocean there is an entire culture of people who are even more obsessed with the mechanics of cutting wood with a plane than we are.

I’m speaking, of course, about the Japanese, who are prone to holding handplaning contests where participants compete to see who can make the longest and thinnest full-width shaving.

They measure the thickness of these champion shavings in microns. And the results are often affected by the weather. A wet day will swell the shavings by a few microns.

Sadly, Western woodworkers have become obsessed by creating ultra-thin shavings, which requires planes to be tuned to a very high note. What’s wrong with this philosophy is that it focuses on the garbage instead of the good stuff. The shavings get thrown away, remember? It’s the resulting work surface that we keep – unless we handplane that all away in some handplaning bliss-fest.

You want to be able to take the thickest shaving you can without tear-out, chatter or requiring you to bulk up like Thundarr the Barbarian. A thick shaving will get you done with fewer passes of the smoothing plane over your workpiece. Not only does this get the job done faster, but it also helps increase your accuracy.

Huh? Think about it. If you make 20 passes over a board with a smoothing plane, you are much more likely to plane that sucker out of true than if you used only four passes.


So how thick should your shaving be? Good question. Most people talk about getting shavings that are less than 2 thousandths of an inch thick. Or they talk about “sub-thou” shavings. Yes, it’s all very empirical, except for the fact that few woodworkers know how to really measure shaving thickness. Squeeze a dial caliper hard enough and you can make almost any shaving into a “sub-thou” shaving. Wood compresses. Metal bends.

So I go for visual cues instead.

If the wood is well-behaved, I go for an opaque shaving – that is, as long as the curvature of the cutting edge of my iron is significant enough to keep the corners of my iron from digging into my work. I’ve included a photo above of what this shaving looks like. This shaving gets the work done fast. If the surface has been flattened by a jointer plane, a shaving like this will get the work done in one or two passes.


If I get tear-out using a beefy shaving, I’ll retract the iron fully into the mouth of the handplane and extend it until the shaving looks like the photo above. Here you can see the shaving is thinner, but it is still intact except for one area.

That split in the shaving is probably caused by a small defect in the iron. The edge is probably getting dull and is ready for a touch-up. This shaving will clean up my surfaces in three of four passes. It usually eliminates tear-out more than the shaving above. But sometimes I need to get a little nuttier.


And that’s when I push my tool to get a shaving like the one above. This thing is about to fall apart. In fact, it sometimes will fall apart when you remove it from the mouth of the tool. Usually, this sort of shaving requires some persnickety set-up to achieve. I can’t get this shaving with an Anant, new Stanley or Groz plane. They are just too coarse to allow this type of shaving to pass. This is what you are paying your money for when you buy a premium tool. Premium tools will do this with little fettling. My vintage planes that I've fussed over will do this as well. A sharp iron always helps, as well.

The downside to this shaving is that you will be making a lot of them to remove the tear-out on the board. About 10 cycles or more is typical for some small tear-out. It is a lot like working.

Can you get nuttier? Sure. If all else fails, I can set my plane to remove something between a shaving and dust. These “shavings” don’t really look like much. How do you get them? That’s easy. When I get my thinnest smoothing plane shaving possible, I’ll rub some paraffin on the sole of the tool. This actually reduces the depth of cut just enough to get the furry, dusty stuff. Beware: Taking a shaving that small will force you into a lot of work. Lots of passes. Lots of sharpening.

But when you need it, you need it.

— Christopher Schwarz

Friday, December 07, 2007 8:16:41 PM (Eastern Standard Time, UTC-05:00) #    Comments [6]  | 

 

Saturday, December 08, 2007 8:41:12 AM (Eastern Standard Time, UTC-05:00)
Great post Chris. It is nice to every so often get things back into perspective. We can get carried away with our thin shavings and forget what we are really doing. Happy holidays and again thanks for the blog entries. AFFW John
John Borgwardt
Saturday, December 08, 2007 9:22:18 AM (Eastern Standard Time, UTC-05:00)
Sweet,this was reinforcing what I knew, this is a good thing. When you mentioned using wax to adjust blade depth! Methods like this are treasure! Thanks, this site has been bookmarked.

Bob
Saturday, December 08, 2007 3:17:20 PM (Eastern Standard Time, UTC-05:00)
"When I get my thinnest smoothing plane shaving possible, I’ll rub some paraffin on the sole of the tool. This actually reduces the depth of cut just enough to get the furry, dusty stuff."

Interesting point Chris..
I often wonder why the characteristics of my plane change ever so slightly when I scribble some paraffin on the sole, which I tend to do often in a hand planing session. It now makes sense!

Norman
Sunday, December 09, 2007 3:09:02 PM (Eastern Standard Time, UTC-05:00)
I use paraffin wax to help the plane glide more smoothly but never thought of using it as a depth adjustment. Cool tip!
Monday, December 10, 2007 1:41:04 PM (Eastern Standard Time, UTC-05:00)
This blog post is exactly why I so enjoy your DVDs, books and articles. Thinking about what we're doing, trying different approaches, and paying attention to the results. I'm on the wait list for the handsawing class at Kelly Mehler's. I do hope I get in.
Chuck Nickerson
Tuesday, December 11, 2007 3:32:45 PM (Eastern Standard Time, UTC-05:00)
Chris;
Another very good post. I am glad to see someone has debunked the myth of the super shaving. What works is what is best, why make ten passes when you only need five.
larry
Larry Feasel
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