To put on the cover.
Fig. 55. Plane Iron.
A seen from the front 1/4.
B seen from the side 1/1, a iron, b cover.
In planes like the smoothing-plane and the trying-plane, where the iron is narrower than the sole, and is inserted in the socket from above, the front side of the socket should be at right angles with the plane of the sole, and of the same breadth as the iron. The inclination of the side of the socket on which the iron rests has been already indicated; the other two sides, i.e., the cheeks, are thicker towards the iron, in order to give support and steadiness to the wedge, and the sides of the wedge are inclined towards one another at an angle of about 8°. If this angle is much greater the wedge fits loosely ; if it is less it may fit so tightly that it cannot without difficulty be loosened. The wedge, which is forked at the lower end, must fit accurately into the space in the socket left by the iron, otherwise shavings may gather round its points (see Fig. 56). These points require frequently to be trimmed, because from repeated sharpening the wedge-shaped plane-iron gradually sinks deeper in the socket, causing the wedge to do the same.
The wedge and the socket.
Fig. 56. Portion of Plane. Socket, 1/4.
.F section through cd showing plane-iron, wedge and piece of wood inserted.
Should the sole of the plane become warped, or uneven through wear, it must be carefully planed. It follows from the construction of the socket that the opening in front of the iron, after repeated planing, becomes too large. It is usual to remedy this by inserting in front of the iron a piece of very hard wood, e.g., ebony, beech, or boxwood (see Fig. 56). Brass is also used for this purpose. New planes are also, often furnished with such pieces, in order that the portion in front of the plane-iron's edge may longer resist the wearing effect of the shavings.
Planing the sole and inserting a piece of wood.
Putting in the Plane-Iron or Setting the Plane.
The cover is screwed tightly on the iron, with its sharp edge at the proper distance from the edge of the iron, which is then laid in the socket, just deep enough to allow its edge to lie in the same plane as the surface of the sole. The wedge is then put in, and secured by a couple of light blows from the hammer. The plane is then taken in the left hand, with the thumb resting on the wedge in the socket. The sole is turned upwards, and the iron is carefully driven in a little more, so that its edge shows just as much beyond the plane of the sole as the occasion requires. If it seems crooked, i.e., if one corner seems lower than the other, this must be rectified by light taps on its free edges. When its position appears to be right, the iron is secured by driving the wedge in more firmly. If, after this, the iron is found to be too low, it may be made to recede by a blow on the back part of the stock, or, in the case of the trying-plane, by a blow on the boss, a piece of hard wood or metal inserted in front of the socket (see H, Fig. 54). [This boss is not always found in English planes. It is useful in slojd as indicating the place to which the blow should be directed, and thus saving the stock of the plane from injury. - Trs.] The loosened wedge is then fastened once more, and the position of the iron is tested by the thickness of the shavings it removes, and raised or lowered, if necessary, according to the above directions. When the iron is removed, the plane is held in the way indicated above.
1. Planes with Flat Soles for the dressing of plane surfaces.
1. The jack-plane (Fig. 57). To give certainty and ease in working, the front portion of the stock of a Swedish jack-plane is furnished with a horn for the hand, and a metal support of American invention is sometimes placed behind-the iron to prevent the other hand from coming in contact with its sharp edges. The iron is single, i.e., it has no cover, and the edge is curved, not square. The Swedish jack-plane is 9 1/2 inches long. [The English jack-plane is 16 inches long. - Trs.]
Length of the jack-plane.
The jack-plane is" used on rough un-planed surfaces as a preparation for a finer plane, when the object in view is more to remove thick shavings rapidly by an iron which cuts deep, than to produce a smooth surface. As the iron is single, and the opening in front of it tolerably wide, the jack-plane has a tendency to tear up the wood; and it is therefore not advisable to use this tool very near the surface which is ultimately to be produced.
2. The trying-plane is the largest and most indispensable of all the planes in use. That it may be wielded steadily it is provided with a handle for one hand. The iron is double, i.e., provided with a cover. Its various parts and their construction are fully described in connection with Fig. 54, and the method of using it is described in Chap. V.
Fig. 57. Jack-plane. 1/4. A horn, B support for hand, C single iron.
It is employed in shooting, i.e., in producing level surfaces of all kinds, and it is sometimes used in preparatory work instead of the jack-plane, in which case the iron should be set rather deeper than for shooting. When the trying-plane is used instead of the jack-plane, the space between the socket and the edge of the iron in front should be wider than in the later stages of planing.
Use of the trying plane
In all planes used for shooting, the surface of the sole must lie altogether in the same plane ; and the edge of the plane-iron must be ground quite straight, and at right angles with the middle line of the iron. As, however, the corners of a perfectly straight-edge are apt to tear up the fibres by the side of the iron, or at least to leave a mark on the wood, they should be very slightly rounded. The sole is sometimes rubbed with raw linseed oil, that it may glide more smoothly over the wood.