Tuesday, May 4, 2010

Learning to Plane - Part IV

Setting Up Planes

There really isn't much setup to do on bevel-up planes, which is one of the reasons they are increasingly popular, especially with beginning woodworkers.  Chris Schwarz didn't have much to offer on setting them up, except to adjust the mouth tightly for difficult woods. 

Bevel-down planes, on the other hand, usually have chipbreakers.  Chris offered that a dished chipbreaker can be honed using a honing guide.  Most people, he said, set the chipbreaker too close to the edge of the blade.  One-sixteenth of an inch is a good distance, except for difficult woods, when it should be set closer, such as one thirty-second of an inch.  Lie-Nielsen makes a standard 45-degree frog but also 50 and 55 degree frogs for difficult woods for all its planes.

Planes are tuned either to remove material, straighten a board or prepare it for finishing.  The jack or fore plane is generally used to remove material.  These are the #5 and #6 planes.  For stock removal, set the plane with a wide open mouth, say 1/16 inch.  Use a curved blade with and 8-10 inch radius.  Back the chipbreaker off; get it behind the curve of the blade.  Use a low blade pitch, say 45 degrees.  For a bevel up plane, set it even lower.

The jointer plane's main job is to straighten a board once excess material has been removed.  Jointer planes are #7 and #8 and run from 18 to 24 inches in length.  You tighten the mouth of a jointer plane; you want to get shavings about .004 or .005 inches thick, so set the mouth at about .003 inches.  Give the jointer plane a strong curve, say .006-.008 inches from the top of the arc to a line drawn between the edges of the blade.  Use an even stronger arc for a bevel-up plane and a 45 to 50 degree pitch.  On a bevel-down plane, the chipbreaker should be backed off to, say, 1/16 inch. 

Smoothing planes should be set with the mouth as tight as possible, .003-.004 inch.  Use a feeler gauge to assess this.  A narrow mouth reduces tearout.  Use a very slight curve to the blade, .002-.003 inches.  Keep the chipbreaker set so it won't clog; 3/32 inch is where Chris starts.  The pitch of the blade can be from 45 to 65 degrees.  The higher the pitch, the less tearing.  Plane softwoods at a lower angle, hardwoods at a higher angle.

Chris argues that it's good practice to use the jack plane and jointer plane as much as possible for smoothing to avoid unnecessary work with the smoother.

Next I'll talk about putting the planes to work on an actual piece of wood.


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