Fig. 638.
In planing pieces with crooked grain, turn the piece when practicable, so as to plane as much of it with the grain as you can. But many pieces are so crooked in grain that you cannot do this. So at times it is well to turn your plane sideways to get a slicing cut and cross the grain at an angle (Fig. 638); but as a rule the plane should be pushed straight forward.
A few drops of oil rubbed over the face of the plane will make it run more smoothly, particularly on hard wood.
Fig. 639.
Test the accuracy of your planing of broad surfaces with a straight-edge, the blade of a square, or the edge of the plane itself (if straight). By applying such a straight-edge across the surface or lengthways or diagonally you can tell whether your work is straight and true (Fig. 639). Also "sight" with your eye. If the surface is large or long, winding-sticks can be used (see Winding-sticks). In planing edges test lengthways with the eye and straight-edge of some sort, and crossways by applying the try-square (Fig. 640). (See Jointing.)
Fig. 640.
Fig. 641.