Twisted Board

STEPl:

Establish flats on two high corners of board.

Rough plane diagonally across the board. Plane in from the edge where possible rather than off the edge to minimi» tear-out

I prefer to start by planing the concave face of a cupped or bowed board. It can be difficult to keep the plane from following a convex curvature. (However, if a badly cupped or bowed board rocks too much while I'm planing its concave face, I'll plane the opposite, convex face first.) With twisted boards the same logic applies—span high spots rather than rock on ridges. However, it's often a tossup as to which face will be easier to plane.

Correcting cupped, bowed or twisted boards is a matter of planing oft the high spots. Unfortunately,

Rough plane diagonally across the board. Plane in from the edge where possible rather than off the edge to minimi» tear-out this is easier to say than to do. The trick, if there is one, is to try to plane off the least amount of wood. If you're planing the convex face, establish a Hat surface, and extend it equally in all directions until you reach the low spots. For concave faces this means removing equal amounts of wood from opposing high spots. (See Fig. 4.) A good example of this is boards with just one defect—such as being cupped. Twisted boards are a little more complicated than cupped or bowed boards, but the remedy is the same—remove equal amounts from diagonally opposed high spots, as shown in Fig. 5. Most boards are cupped and bowed and twisted, so you'll most often need to feel your way along, checking your progress frequently with a straightedge or by eye and adjusting your tactics accordingly. Because you cover much of the surface of a board when correcting for a twist, you can usually take care of the cup or bow as you plane out the twist.

Whatever the defect I'm correcting, I make most of the strokes diagonally across the board, in from both edges. I concentrate on the high spots at first. As the face gets flatter, I cover more of it. The final strokes are along the length of the board, covering its entire surface. Even when I'm using diagonal strokes, I make an effort to plane with the grain wherever possible. The quickest way to determine the direction of the grain is by planing—if you're going against the grain, you'll usually feel, hear and see it. A less nerve-wracking method of determining grain direction is to examine the annual rings along the edge of the board, as shown in Fig. 6.

Though you often want to remove a lot of wood quickly when face planing, thicker shavings mean harder work. The position of the chip breaker on the

To reduce a board's thickness, scribe the desired thkkness around the edge with a marking gauge, working from the face you've already flattened. Then plane to the line.

FIG. 6: PLANING WITH THE GRAIN

Was this article helpful?

0 0

Post a comment