Part 23 (1/2)
[Ill.u.s.tration: Fig. 268.
52 Miter 53 Doweled miter 54 Spline miter 55 Slip feather miter 56 Slip dovetail miter 57 Double dovetail keyed 58 Ledge and miter 59 Stopped miter 60 Double tongue miter 61 Stretcher 62 Strut 63 Square thrust 64 Oblique thrust]
[Ill.u.s.tration: Fig. 269.
65 Brace 66 Housed brace 67 Oblique mortise and tenon 68 Bridle 69 Bird's mouth 70 Glue 71 Rabbeted 72 Matched 73 Beaded 74 Spline 75 Doweled]
CHAPTER VIII.
TYPES OF WOODEN STRUCTURES.
The articles suitable to be made in wood with hand tools may for convenience be divided into four general cla.s.ses: (1) Unjoined pieces; (2) board structures; (3) panel structures; (4) framed structures. A few ill.u.s.trations of each cla.s.s are given below.
(1) SIMPLE OR UNJOINED PIECES
Of these there are a number that are advantageous for the learning of tool processes; at the same time they give opportunity for expression in design, and when finished are of use.
Examples are: key-boards, chiseling-boards, bread-boards, sleeve-boards, ironing-boards, coat- and skirt-hangers, and gouged trays. Some of these are so simple as to include hardly any process but planing, directions for which are given above, p. 72.
[Ill.u.s.tration: Fig. 270. Pen-Tray.]
Where there is more than one process involved, the order of procedure is of importance. In general, a safe rule to follow in each case is to plane up the piece true and square, or, in technical language, to ”true” it up. At least as many of its surfaces should be trued as are necessary for the ”lay out.” Where the piece is to be rectangular all the surfaces should be true; where some of the surfaces are to be curved it is unnecessary and a waste of time to square them first. For example, in making a gouged tray with curved outline, Fig. 270, the working face, the working edge, and the thickness should all be true before the plan is laid out. Then, after the outline is drawn, the trough may be gouged, the outline cut with turning-saw, chisel, and spokeshave, and the edges molded with the gouge or chisel. If there is incised decoration it should be cut before the molding is cut, so that while being incised, the piece will lie flat without tipping.
These simple pieces, as well as others, are often embellished by _chamfering_. A chamfer is a surface produced by cutting away an arris. It differs from a bevel in that a bevel inclines all the way to the next arris, while a chamfer makes a new arris, Fig. 271. A thru chamfer extends the whole length or width of a piece, while a stop chamfer extends only part way. For the laying out of a chamfer see p.
115.
[Ill.u.s.tration: Fig. 271. Difference Between Chamfer and Bevel.]
Thru chamfering is best done with a plane, Fig. 272. For this purpose the piece may be held in the bench-vise and the plane tipped to the proper angle, or the piece may be held in a handscrew which in turn is held in the vise as in Fig. 175, p. 102. The chamfers with the grain should be planed before those across the grain.
[Ill.u.s.tration: Fig. 272. Thru Chamfering.]
In chamfering a four-square stick into an eight-square, the piece may be gripped in the vise diagonally, Fig. 273, or it may be held in a trough made of two strips of wood from each of which an arris has been chamfered and then the two nailed together, Fig. 274. A dowel or nail may be inserted in the trough for a stop. Stop chamfers are pared best with a chisel, Fig. 275, held according to convenience either flat side or bevel side up. See under chisel, p. 53.
[Ill.u.s.tration: Fig. 273. Piece Held in Vise to Chamfer.]
[Ill.u.s.tration: Fig. 274. Trough for Planing Chamfers.]
[Ill.u.s.tration: Fig. 275. Stop Chamfering.]
(2) BOARD STRUCTURES.
These include such pieces as wall brackets, sets of shelves, book-racks, plate-racks, drawing-boards, foot-stools, taborets, and boxes.
The advantage of this form of construction is that it is comparatively easy to make; the disadvantage is that if the boards are wide, they are sure to shrink and swell. It is wise in all such work to true and smooth up all the pieces at once, and if the wood is not thoroly seasoned, to keep the boards under pressure till they are a.s.sembled.
In the case of several boards to be jointed into one piece, they should be glued together before the surfaces are smoothed. Suggestions regarding a few typical pieces follow: