Friday, May 14, 2010

Learning to Plane - Part V

Chris Schwarz argues that you need a dedicated area for plane sharpening.  After using your planes, dust them off and oil them with either Camilla or Jojoba oil.  The oils won't affect your finish.  In fact, Chris even applies the oil directly to difficult wood or knots to ease planing.  To wax the soles of his planes, Chris uses parafin.  It's essentially mineral spirits.  He waxes after every piece of wood.

Assessing the Wood

Before you plane, look at the end grain.  The bark side of the board is the side where the rings are convex, that is, toward the outside of the tree.  The heart side is where they are concave, or smaller in diameter.  Wood usually cups on the bark side and bows on the heart side.  You tend to get a smooth surface when you plane with the grain.  You can determine that by looking at the edge of the board.  If the grain is rising in one direction, that is the direction you want to plane.  It's like rubbing the fur on the back of a cat; you want to cut with the grain and not against it, which will lead to tearout.  You can also judge from the end grain.  On the heart side of the board, plane from the bottom of the cathedral pattern toward its top.  On the bark side, plane from the point of the cathedral to its bottom.  You would use the same methods to determine the direction for jointing and planing with power tools.  For quartersawn wood, you have to look at the edges; you can't tell from the end grain what direction you should plane.

Assuming the board is cupped, put the bark side down and plane the heart side first.  Once the heart side is flat, flip the board and you can plane without using shims.  When using an end vise, don't put a lot of pressure on the board; the vise can bend it.

Traversing with a Fore Plane

Open the mouth of the plane and use a wide radius (say 8 inches) on the blade.  Plane across the grain.  You can remove lots of wood quickly in this way.  Before traversing (which is what planing across the grain is called), knock off the rear edge of the board, usually with a block plane, to avoid spelching (tearout).

Set the plane on its edge across the board to confirm the existence of a hill.  To remove a hill in the center of the board, plane with the grain to create a slight valley, then traverse the board.  When Chris traverses, he pushes the plane across the board and then pulls it back in a very rapid motion.

Winding Sticks

I took my winding sticks from Philly Planes to the workshop and Chris used those to demonstrate their use.  However, he uses extruded aluminum strips from Home Depot and spray paints one of them black.  Twenty-four to thirty-six inches is a good length.  You can sight at several places on a long board, but you generally don't need to do so.  If you have wind (i.e., the board is twisted), it usually means that two opposite corners are high and you need to plane them.

There's more to tell.  I'll cover it next time.


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.