This tool consists of a highly-tempered piece of steel (Fig.
69). The edges of the scraper are generally straight, but sometimes the ends are rounded or hollowed to suit concave or convex surfaces. The two longest parallel edges are ground at right angles to the sides. When the scraper is sharpened, it is placed at the edge of a plank, and a very hard piece of steel is drawn against its edge as nearly as possible on the plane of the plank. This, when repeated several times backwards and forwards, levels the sharp edge of the scraper, which is raised up again by having the steel once, steadily but not too heavily, passed along it. During this the steel is held almost perpendicular, with its upper end inclined very slightly towards the upper side of the plank. The raised edge of the scraper now forms a fine edge, which takes hold of the wood when drawn across its surface, and removes minute shavings. When it becomes blunt, it must be sharpened once more, and as its edge, after repeated sharpening, becomes uneven, it must finally be re-ground. A worn saw-file, the cut of which has been carefully ground off, and the edges slightly rounded, or a firmer chisel, may be used.
Sharpening the scraper.
Fig. 69. Scraper. 1/4.
The scraper should be held easily in the hand. In polishing a plane surface, the tool should be taken in both hands. The scraper should incline towards the surface of the work (see Chap. V., page 136), and should be worked always in the direction towards which it leans, and with the grain of the wood, but somewhat obliquely to the direction of the fibres. Towards the end, pressure should be diminished, to produce a finer polish. Care must be taken lest the cutting edge become ragged from careless "setting," and scratch the surface. Should this be so, the scraper must be re-ground, and then sharpened.
Method of using the scraper.