Kitabı oku: «Handwork in Wood», sayfa 9
Fig. 268-56 Slip dovetail miter
No. 57. A double dovetail keyed miter is one in which a double dovetail key made of hard wood is inlaid across the joint. This is a favorite joint with Oriental joiners.
Fig. 268-57 Double dovetail keyed
No. 58. A ledge and miter or lipped miter joint is made by rabbeting and mitering the boards to be joined so that the outer portion of the two boards meet in a miter. It is strong and good looking and may be glued or nailed. It is used for fine boxes.
Fig. 268-58 Ledge and miter
No. 59. A stopped miter is useful for joining pieces of different widths, when both sides can be seen.
Fig. 268-59 Stopped miter
No. 60. A double-tongue miter is made by cutting on the adjoining edges tongues which engage in each other. It is used in high class joinery, on members that join lengthwise of the grain.
Fig. 268-60 Double tongue miter
No. 61. A stretcher joint is a slip joint in which one or both sides is mitered. It is used in frames for stretching canvass for paintings by driving wedges from the inside. Two forms are shown in 61a and 61b.
Fig. 268-61 Stretcher
No. 62. A strut joint is a form of miter joint used in making trusses.
Fig. 268-62 Strut
No. 63 and 64. A thrust joint or tie joint or toe joint is one in which two beams meet at an oblique angle, one receiving the thrust of the other. The toe may be either square as in 63, or oblique as in 64. The pieces are bolted or strapped together with iron. It is used for the batter braces of bridges.
Fig. 268-63 Square thrust
Fig. 268-64 Oblique thrust
No. 65. A plain brace joint is one in which the brace is simply mitered and nailed into place. It is used for bracket supports.
Fig. 269-65 Brace
No. 66. A housed brace joint is a joint in which the brace is housed into the rectangular members except that the outer end of the mortise is cut at right angles and the inner end diagonally to receive the brace which is cut to correspond. It is much stronger than 65.
Fig. 269-66 Housed brace
No. 67. An oblique mortise-and-tenon or bevel-shoulder joint is one in which the shoulders of the tenoned beam are cut obliquely and its end is cut off at right angles. The cheeks of the mortise are correspondingly sunk. By these means the tenon prevents lateral motion while the whole width of the beam presses against the abutment. Thus a much larger bearing surface is obtained. The whole is bolted or strapped together. It is used in heavy truss work.
Fig. 269-67 Oblique mortise and tenon
No. 68. A bridle joint is an oblique joint in which a bridle or "tongue" is left in an oblique notch cut out of one beam. Over this tongue is fitted a grooved socket cut obliquely in the other beam. It is used in truss construction.
Fig. 269-68 Bridle
No. 69. A bird's mouth joint is an angular notch cut in a timber to allow it to fit snugly over the member on which it rests. It is used in rafters where they fit over the plate.
Fig. 269-69 Bird's mouth
No. 70. A plain or rubbed or squeezed or glue joint is one in which the edges of two boards are glued and rubbed together tight. It is used in table-tops, drawing-boards, etc.
Fig. 269-70 Glue
To make this joint, first the boards are all laid down flat, side by side, and arranged in the proper order. Three considerations determine what this order is to be: (1), if the grain is of prime importance, as in quartered oak, then the boards are arranged so as to give the best appearance of the grain. (2), if possible, the boards should be so arranged that the warping of each board shall counteract that of the adjacent ones. For this purpose the boards are so laid that the annual rings of one shall alternate in direction with the annual rings of the next, Fig. 280, a, p. 186. (3), if possible, the boards should be so arranged that after being glued together they can all be planed smooth in the same direction. When the above requirements have been met so far as possible, this order should be marked on adjoining edges for later identification. The edges of the boards to be joined should be finished with a jointer.
There are two principal methods of gluing edge-to-edge joints, rubbing and squeezing. In a rubbed joint, the surfaces to be joined should be planed so as to meet thruout exactly. After properly planing one edge of each board, keep one board in the vise, jointed edge up, and place its to-be neighbor in position upon it. Then use these four tests for an exact fit. (1) Sight down the end to see that the faces lie in the same plane. (2) Examine the crack from both sides. Be sure that both ends touch. Test this by pulling down hard on one end of the upper board and noticing if the other end is still in contact. If the other end opens, swing the upper board horizontally on the lower board to see where the high place is and then correct it. (3) See if the upper board stands firmly on the lower board by feeling gently to see if it rocks, or by rapping lightly the lower board. (4) Slide the top board slowly on the lower one to see if it adheres or "sucks."
Fig. 260. Applying Glue for an Edge-to-Edge Joint.
After the pieces have been warmed, which should be done if possible, the glue is spread on them, Fig. 260, and they are then rubbed slowly back and forth in the direction of the grain, pressure being applied by the hand and care being taken not to open the joint in the least. As the glue sets, the rubbing becomes more difficult. It should be stopped when the boards are in their proper relative positions. In rubbing together the edges of two boards, handscrews may be fastened to one in such a way that their jaws serve as guides for the other board to slide between, Fig. 261. Care must be taken to make the jaws of the handscrew diverge enough not to pinch the upper board.
Fig. 261. Rubbing a Glued Joint.
Another method is to clamp a spare board alongside and projecting above the lower board. This spare board acts as a guide against which the upper board can be pushed as it is rubbed back and forth. The rubbed joint is especially suitable for short boards.
In joining long boards, a squeezed joint is common. In this case, the edges are planed so as to be very slightly concave from end to end. The object of this is to counteract the subsequent shrinkage which is likely to take place at the ends of the boards before it does at the middle. The pressure of the clamps may be depended upon to close up the middle, and, especially if dowels are inserted, as in No. 75, the joint will be strong enough to resist the elasticity of the boards.
When the fit is good, warm the wood if possible, prepare the clamps, put a thin film of glue over both edges which are to be together, apply the clamps rapidly, keeping the faces flush, and set away to dry for at least six hours. Then another piece may be added in the same manner. If the boards are thin and wide, and therefore likely to buckle, they may first be handscrewed to cross-strips to prevent their buckling. The cross-strips are, of course, slightly shorter than the combined width of the boards so that the full pressure of the clamps may come on the glued joint.
No. 71. A rebated, rabbeted or fillistered joint. Rebating is the cutting of a rectangular slip out of the side of a piece of wood. The re-entering angle left upon the wood is called the rebate or rabbet. A rebated joint, then, is one in which corresponding rebates are taken off edges so that the joined boards may overlap. It is used in flooring and siding.
Fig. 269-71 Rabbeted
A board is rebated and filleted when two adjoining rebates are filled with a fillet.
Fig. 262. Edge-to-Edge Joint, Doweled.
No. 72. A matched or tongue-and-groove joint is made by making a projection or "tongue" in the center of the edge of one board, and a corresponding groove in the center of the other so that they will match together. When used for flooring, the lower side of the grooved board is slightly rebated so that the upper edges will surely touch. This sort of flooring can be blind-nailed.
Fig. 269-72 Matched
No. 73. A beaded joint is similar to a matched joint except that a bead is worked on one edge to disguise the joint for decorative purposes.
Fig. 269-73 Beaded
No. 74. A spline-joint is made by plowing corresponding grooves in the edges to be joined and inserting a spline or slip-feather. It is used in plank flooring.
Fig. 269-74 Spline
No. 75. A doweled joint is made by jointing the two edges carefully, boring holes opposite each other and inserting dowel pins when the two edges are glued together. It is used in table tops, etc.
Fig. 269-75 Doweled
Where the boards are thick enough to allow it, a squeezed joint is greatly strengthened by the insertion of dowels.
The essential point in inserting dowels is to have the holes for them directly opposite one another and at right angles to the surface. The following is a convenient method where boards are to be joined edge to edge, Fig. 262. Place the two boards back to back in the vise with the edges and ends flush. Determine approximately where the dowels are to be inserted. With the gage, mark short lines at the points of insertion in the center of each edge, gaging from the outside faces. Across these lines score accurately with a try-square and knife. Then bore the holes with a dowel-bit at the intersection of the lines, Fig. 263. If this is carefully done, the holes will be directly opposite one another, and equidistant from the faces of both boards. All the holes should be of equal depth, say 1", in order that the dowel-pins, which should also be cut of equal lengths, may be interchangeable. After boring, the holes may be slightly countersunk in order to insure a tight joint and the easy slipping of the pins into place. The latter result may also be obtained by slightly pointing the pins with a dowel-pointer, Fig. 123, p. 83. It is also a wise precaution to cut a small groove along the length of the pin to allow superfluous glue to escape from the hole. The dowel should be dipped in glue and inserted when the glue is applied to the joint.
Fig. 263. Boring for Dowels in an Edge-to-Edge Joint.
THE COMMON JOINTS
References17
Rivington, Vol. I, pp. 57-77, 135-137, 238-242; Vol.II, pp. 291-295.
Adams, pp. 1-30.
Sickels, pp. 86-124.
Goss, pp. 128-152.
Ellis, pp. 135-151.
Barter, pp. 211-275.
Selden, pp. 56-130.
Building Trades Pocketbook, pp. 217-221, 237.
Griffith, pp. 86-104, 164-170.
Fig. 264
1 Lapped and Strapped
2 Fished
3 Fished and keyed
4 Spliced for compression
5 Spliced for tension
6 Spliced and Tabled
7 Spliced for cross strain
8 Dowelled butt
9 Toe-nailed
10 Draw-bolt
11 Plain butt
12 Glued and blocked
13 Hopper
14 Cross lap
Fig. 264
Fig. 265
15 Middle lap
16 End lap
17 End lap with rabbet
18 Dovetail halving
19 Beveled halving
20 Notched
21 Checked
22 Cogged
23 Forked
Fig. 265
Fig. 266
24 Rabbet
25 Dado
26 Dado and rabbet
27 Dado tongue and rabbet
28 Dovetail dado
29 Gain
30 Stub mortise and tenon
31 Thru mortise and tenon
32 Blind mortise and tenon
33 Mortise and tenon with rabbet
34 Wedged mortise and tenon
35 Wedged mortise and tenon
36 Fox tail tenon
37 Dovetail mortise and tenon
Fig. 266
Fig. 267
38 Pinned mortise and tenon
39 Keyed mortise and tenon
40 Tusk tenon
41 Double mortise and tenon
42 Haunched mortise and tenon
43 Table haunching
44 Bare faced tenon
45 Housed mortise and tenon
46 Slip
47 Thru single dovetail
48 Thru multiple dovetail
49 Lap dovetail
50 Stopped lap dovetail
51 Blind dovetail
Fig. 267
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
Fig. 268
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
Fig. 269
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 classes: (1) Unjoined pieces; (2) board structures; (3) panel structures; (4) framed structures. A few illustrations of each class 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.
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.
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. 101. The chamfers with the grain should be planed before those across the grain.
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.
Fig. 273. Piece Held in Vise to Chamfer.
Fig. 274. Trough for Planing Chamfers.
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 assembled. 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:
Wall Brackets. (1) There are three essential parts, the shelf, the support or supports, and the back: the shelf to hold the articles, the support to hold up the shelf, and the back to hold all together, Fig. 276, a. The grain of the wood in the shelf should run left and right, not forward and back, because thus it rests on the support in such a way as not to break easily, and it also acts as a stiffener for the back. In case the back extends above the shelf, as in Fig. 276, a, the shelf can be secured firmly to the back, since there is side grain in which to drive nails or screws. As to the direction of the grain of the support and the back, this should run in the direction of the largest dimension of each. Where the back is long horizontally, for security in hanging, it is better to have two supports.18
Fig. 276. Wall Brackets, Double-Hung: a. Single Support. b. Double Support.
Wall book-shelves, Fig. 277, plate-racks, etc., are simply compound brackets. The shelf is the essential piece, the sides take the place of the supports, and the back is often reduced to strips merely wide enough to give rigidity.
The shelves may be either gained into the supports, Fig. 266, No. 28 or No. 29, p. 179, or a keyed mortise-and-tenon may be used, Fig. 277. In the latter case the back strip may have a short barefaced blind tenon which is mortised into the upright, Fig. 278. It also fits into a rabbet on the upper back side of the shelf. Made in this way the shelves can be knocked down easily.
Fig. 277. Wall Book-Case.
Fig. 278. Construction of a Knock-Down Book-Shelf Seen From the Back.
Foot Stool or Cricket, Fig. 279. The grain of the supports should run up and down, because pieces with the grain horizontal would be likely to break under pressure. Braces or a rail give additional support. The top should not be larger than the base of the legs; otherwise a person standing carelessly on the stool is in danger of being upset.
Fig. 279. Cricket.
A Drawing-Board is made up of narrow boards, with glued joints, with the boards so laid that the annual rings will alternate in direction, Fig. 280, a. It must be made so that it can shrink and swell and yet remain flat. For the purpose of giving lateral stiffness cleats are added. They may simply be screwed on the underside, the screw holes being large enough to allow for shrinkage, or they may be dadoed in with a dovetail dado, Fig. 280, b, or they may be grooved to admit a tongue on the end of a board, Fig. 280, c. In this case screws passing thru large holes in the cleats hold them in place.
Fig. 280. Drawing-Board Construction:
a. With Cleats Screwed on Beneath;
b. With Cleats Dovetail-Dadoed in;
c. With Cleats Matched on Ends.
Taborets. The term taboret originally meant a little tabor or drum, and was therefore used to designate a small stool, the seat of which consisted of a piece of stretched leather. The term now includes small, tablelike structures for holding flowerpots, vases, etc. It might more properly be called a "table-ette."
When made up with boards having their long edges mitered, it has from four to eight sides. A six-sided one is shown in Fig. 281. In making, it is best to fit the joints exactly first, while the board is stiff, and then to cut out the pattern of the legs. Directions for gluing are given on p. 169.
Fig. 281. Taboret.
Scrap-boxes, Fig. 282, and flower-pot boxes may be made with the same construction.
Fig. 282. Scrap-Box.
Rectangular Boxes. There are various methods of joining their sides. The butt joint, Fig. 264, No. 11, p. 177, is plain, simple, and good for coarse work. This joint may be reinforced as in packing boxes, Fig. 283.
Fig. 283. Reinforced Butt Joint in Box.
Mitered joints, Fig. 268, No. 52, p. 181, are neat but weak, unless reinforced by a spline, Fig. 268, No. 54.
The rabbet or ledge joint, Fig. 266, No. 24, p. 179, is both strong and neat. It can be glued and also nailed if desired.
The rabbet and dado joint, Fig. 266, No. 26, can be glued without nails and is good for small boxes.
The housed dado, Fig. 266, No. 25, is good for water-tight boxes.
The mitered ledge, Fig. 268, No. 58, makes a very neat, strong joint which can be nailed or glued, but is more difficult to fit than a simpler joint.
The dovetail joint, Fig. 267, No. 48, is very strong and honest, but the joint is prominent from the outside and it takes much time and labor to make. It is glued.
The blind dovetail, Fig. 267, No. 51, is very neat and strong, and the joint is entirely concealed when done, but is very difficult to make.
The Bottoms of Boxes. The plain or full bottom, Fig. 284, A, is likely to shrink (see dotted line), and it is held in place only by the friction of the nails. The extended bottom, Fig. 284, B, overcomes the objection to shrinkage and adds a decorative feature. The bottom may be set in, Fig. 284, C. This is stronger than the plain bottom, but the nail holes show. The bottom may be rabbeted in, Fig. 284, D. This is better than the set-in bottom so far as the showing of the nail holes goes, for the nails may be driven in from below, and a little shrinkage is not conspicuous. It is practicable, if a rabbet or mitered joint is used in the sides, but if the side pieces are butted or dadoed, the rabbet for the bottom shows. This may be cleverly concealed by an insert, but that is patchwork, and not first-rate construction.
Reinforced bottom, Fig. 284, E. A plain or full bottom is sometimes covered by a base or cover strip to hide the joint and secure the bottom, as in tool chests. This strip may be mitered at the corners.
Fig. 284. Methods of Attaching Box Bottoms.
The Lids of Boxes. The simplest form is a full flat cover, Fig. 285, A, which may be nailed or screwed to the box, as in packing cases. The cover may slide into a groove, Fig. 285, B, along the sides and into one end, the other end being lowered to admit it. The cover may have cleats on its underside, Fig. 285, C, which fit just inside the box and keep the top in place. The cleats also prevent the top from warping. This is a common Japanese construction, even in fine boxes. The Japanese tie the top on with a tape or ribbon.
The lid may be boxed, Fig. 285, D, that is, portions of the sides may be affixed to the top. These extra pieces are a help to stiffen the top and to keep it from warping. A boxed top may have the top board flush with the sides, Fig. 285, E. The disadvantage of this is that the top may shrink and part from the sides and give a bad appearance. The overlapping top, Fig. 285, F, obviates this trouble of shrinkage and adds a decorative element. In this case the top may be glued on or screwed from below thru the side strips.
The top may be mitered into the sides, Fig. 285, G. The shrinkage trouble still obtains here. Otherwise the appearance is excellent. The top may be paneled into the sides, Fig. 285, H. This has a good appearance if the sides are mitered and ledged but not if the sides are butted or dadoed, because then the groove for the top shows.
Fig. 285. Forms of Box Construction.
Any of these lids may be made removable or hinged, except the sliding top. For methods of hinging see p. 132.
In gluing boxes together, it is a good plan to glue the ends and sides together first and to let these joints dry before gluing on the bottom and, in the case of a boxed top, Fig. 285, D, the top. Care must be taken to see that the sides do not bow under the pressure. To prevent this, one or more false, temporary partitions as A, B, in Fig. 286, of exactly the length to keep the sides straight, may be inserted. In gluing together boxes with rabbeted joints, Fig. 285, H, pressure should be applied in both directions. In gluing on the bottom of a box that is also to be nailed, the nails should be driven into the bottom first, so that the points just come thru. These points sticking into the sides will prevent the bottom from slipping when pressure is applied. It is often undesirable to have nail heads show, as in a top. In such a case, and also to prevent the top from slipping under pressure, a couple of small brads may be driven part way into the upper edges of the sides, the heads bitten off with the nippers, and points filed on the projecting portion.
Fig. 286. Glueing Together a Box.
Drawers. In the best form, the sides are dovetailed to the front for strength, Fig. 287, for whenever the drawer is opened the front tends to pull away from the sides. This dovetail is half blind, so that the joint will not appear when the drawer is shut. In order that the drawer may always run freely and yet the front fit the opening as close as possible, it is common practice to cut a shallow rabbet on the ends of the front, so that the body of the drawer is a little narrower than the front is long, Fig. 287. Or the front may be attached to the sides with a dado tongue and rabbet joint, Fig. 266, No. 27, p. 179.
Fig. 287. Dovetailed Drawer Construction.
The bottom is grooved into the sides with its grain parallel to the front and fastened only to the front so that it has plenty of play for shrinkage. The back is dadoed into the sides, with either a straight dado, Fig. 266, No. 25, p. 179, or dovetail dado, Fig. 266, No. 28, and rests on the bottom. The extension of the bottom beyond the back allows ample room for shrinkage.
The best machine-made drawers are now made with the bottom paneled or dadoed in all around so that papers cannot slip out. The back, as well as the front, is dovetailed.
Directions for Making a Table Drawer. Dress the front and sides to size. Fit the front of the drawer to its place in the table or cabinet, leaving a little play all around it. Plow the groove in the front and sides for the drawer bottom. For ordinary drawers, a groove ¼" wide is proper. If the ends of the front are to be rabbeted (see above), do this next. The sides are best joined to the front with the half-blind dovetail joint. (For directions see p. 166). After fitting these, lay out and cut the dadoes for the back of the drawer. Prepare the bottom of the drawer thus: the grain should run right and left, never front and back. If the drawer is so long as to require it, glue-joint the bottom, and fit it snugly to place. There need be no play right and left, and the bottom should extend as far back as the sides. If necessary, bevel the under side to fit the grooves. Assemble all the parts to see that they fit, take them apart, glue the sides to the front and back, slip the bottom into place, apply the clamps, and see to it that all joints are square, using a diagonal brace if necessary, Fig. 294. Fasten the bottom to the front by means of a thin block glued into the interior angle between the under side of the bottom and the back side of the front. When dry, clean up the drawer and fit it to its place.
(3) PANEL STRUCTURES
These include doors and cabinets of all sorts. The principle of panel or cabinet construction is that there shall be a frame composed of narrow members whose grain follows the principal dimensions. In the best construction this frame is mortised and tenoned together and within this frame there is set a thin board or panel which is free to shrink or swell but is prevented from warping by the stiffer frame. The object is to cover an extended surface in such a way that the general dimensions and good appearance will not be affected by whatever shrinkage there is. Since the frame itself is made up of narrow pieces, there is but little shrinkage in them. That shrinkage is all that affects the size of the whole structure, because wood does not shrink longitudinally to any appreciable extent. The shrinking or swelling of the panel does not affect the general size. The cross construction of the frame also prevents warping, since, in the best construction every joint is mortised and tenoned. The panel may simply be fastened on the back of the frame, but a better construction is to insert it in a groove made in the inside of the frame in which the panel is to lie and have free play. The panel may be made of one board or of matched boards, may be plain or have raised or carved surfaces, or be of glass; and the joints between frame and panel may be embellished with moldings mitered in, but the principle is the same in all cases.
The frame of a door, Fig. 288, illustrates the panel construction. The upright, outside pieces are called the "stiles," the horizontal pieces the "rails." There are also the "top-rail," the "bottom-rail," the "lock-rail" (where the door-knob and lock are inserted), and sometimes the "frieze-rail" between the lock rail and the top rail. The "muntin" is the upright between the two stiles.
Fig. 288. Door, Illustrating Panel Construction: S. Stile; T. R. Top Rail; L. R. Lock Rail; B. R. Bottom Rail; M. Muntin; P. Panel; A. Double Mortise-and-Tenon; F. Fillet; A. B. C. Forms of Panels.
The joint commonly used is the haunched or relished mortise-and-tenon, Fig. 267, No. 42, p. 180; (See p. 163 for directions for making). The tenon is sometimes doubled, Fig. 288, and a fillet (f) may be inserted to cover the ends of the tenons, or the joint may be a blind mortise-and-tenon, Fig. 266, No. 32, or in cheap construction, dowels may be used. The best doors are now made with cores of pine covered on the visible sides with heavy veneer. Large surfaces are covered by increasing the number of parts rather than their size, as in wainscoting.
Picture-frames also belong in this class of structures, the glass taking the place of the panel. They are made with mortise-and-tenon joints, Fig. 266, No. 33, slip joints, Fig. 267, No. 46, dowelled butt joints, Fig. 264, No. 8, end lap joints, Fig. 265, No. 17, and, far more commonly, mitered joints, Fig. 268, No. 52. Mitered joints are the easiest to make, for the joints can be cut in a miter-box, Fig. 181, p. 103, and glued in a picture-frame-vise, Fig. 172, p. 101. This joint needs reinforcement by nails, Fig. 268, No. 52, by dowels, No. 53, or by splines, No. 55. If the sides are of different widths, the fitting of the joint is more difficult. Mitered joints are the only kind suitable for molded frames. The rabbets are cut out with a rabbeting-plane before mitering and assembling.
The principle disadvantage of a mitered joint is that, if the wood shrinks at all, it opens at the inside corners, as in Fig. 289, because wood shrinks sidewise but not lengthwise.
