Sunday, October 23, 2011

Bevel Up or Down?

At Woodworking in America this year, Graham Blackburn was a last minute addition to the seminar lists as David Charlesworth was not able to attend due to pneumonia. Ouch!

Well, I had the pleasure of attending two classes on plane craft by Graham and the one thing I came away with on the second seminar was:

"If you plane is properly setup, you should be able to take it to any piece of wood in any direction and get zero tearout"

I thought, "Come on! Not possible! No way!"

He said the secret (which is really no secret, only a lesson that needs passing on to those of us learning on our own), is to:
  1. Keep the mouth of the plane open only as wide as the thickness of shaving you want to produce; and
  2. Keep your Cap Iron as close to the cutting edge as the thickness of shaving you want to take.
So, what about bevel up planes I asked. He said at the end of the class that in order to take a plane to any piece of wood in any direction with no tearout, you have to have a cap iron. I was starting to despair that my investment into bevel up Veritas planes was for naught.

Well, I decided to write it off as fanatical dogma. You know, sort of like saying that pins first is the ONLY way to get tight fitting dovetail joints (just ask Tom Iovino and his experience at the Hand Tool Olympics).

Well, when I got home, I decided to give it a try as it had been bugging me for a couple of weeks now and I finally got an opportunity to put it to the test.

I set up my bevel up smoother to take a really fine shaving and closed up the mouth as tight as possible and set out to work on a piece of curly maple. I then did the same with a bevel down smoother.

To my surprise, I was able to get a very clean surface with both planes. It may be that there may be a more gnarly wood out there that will really prove Graham's statement to be true, but I'll have to wait to find that piece of wood another time.

So, bevel up fans, do not despair. At least from a smoothing point of view anyway. I'll be testing this theory in other configurations, but that will be for another post. Thanks Graham, you've helped me grow in my skill level and although I may dispute your statement on the cap iron, it made me think and that's a trait of any great teacher.

3 comments:

  1. Hi Mike,

    If you use a blade in your bevel up smoother with a high enough angle, the steep angle will come close to serving the same purpose of the cap iron.

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  2. True, but changing blades and thus setups can be such a pain. Also, I've still experienced tearout with a 50 degree blade in my jointer. But that was before the lesson I learned from Graham.

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  3. I think what is preventing more tearout in this situation is the tight mouth. It allows you to keep pressure down on the wood fibers directly in front of the cutting action thereby preventing the lifting up of the wood. The chip breaker and/or high angle bevel up blade, simply curls the chip quickly and breaks it. This is done after the chip has already been lifted however so I believe that even a close chip breaker or high angle iron can cause tearout.

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