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 finish

d 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.

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.

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.

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.

(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.10

Footnote 10: See the School Arts Book for Nov., 1906, "Design in the Woodworking Class," by Anna and William Noyes.

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.

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.

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.

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.

Scrap-boxes, Fig. 282, and flower-pot boxes may be made with the same construction.

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.

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.

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.

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.

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.

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.

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.

In window sashes, the dovetail joint, Fig. 267, No. 47, is the common one at the upper end of the lower sash and the lower end of the upper sash, and the mortise-and-tenon joint modified is used at the lower end of the lower and upper end of the upper sash. The glass takes the place of the panel. In blind sashes, the pinned mortise-and-tenon joint, Fig. 267, No. 38, is commonly used.

In all these cases, the constructed panels may be treated as separate boards and joined together with dowel pins or splines or dadoed together without any other framework, tho the corners are often reinforced by cleats or blocks glued into them. Sometimes, however, as in chests, Fig. 290, posts are used instead of stiles, and rails are mortised or doweled into them and the panels set into grooves in both posts and rails. In this case the bottom is raised from the floor, and may be dadoed into the bottom rails, or dowelled into them or even supported by strips attached along their lower inside edges. The chest really is a union of both paneled and framed structures.

(4) FRAMED STRUCTURES

The principle of the framed structure is similar to that of the panel construction in that the object is to allow for shrinkage without harm to construction and also to economize materials. Common examples are tables, chairs, work-benches, and frame houses.

The Making of a Table. The standard height of a table is 30". There should be 25" clearance under the rails. This leaves approximately 4" for the width of the rails. Assuming that the table is to be of a simple straight line type with one drawer, the following method of procedure is suggested:

Cut the boards for the top to the approximate length and stick, (see p. 48) and clamp them, so as to season them as well as possible before jointing.

Dress to size the legs and rails. Stand the legs in their proper positions relative to each other, and mark them F R (front right), F L (front left), B R (back right), and B L (back left). Plow out the grooves on the inside of the rails for the fastenings of the top, Fig. 297, D, if they are to be used. Lay out and cut the tenons and mortises for the end rails and back rail.

The proper form of the tenon is one with a wide shoulder above it so that the top of the leg above the mortise will not shear out. The rails should be set near the outside of the leg so that the tenon may be as long as possible and the portion of the leg inside it as strong as possible. A haunched mortise-and-tenon joint, Fig. 267, No. 43 is sometimes used, giving additional lateral stiffness to the rail. The proper proportions are shown in Fig. 291. When cut, these parts should be temporarily assembled to see if they fit.

Inasmuch as a drawer takes the place of a front rail, the front legs must be tied together in some other way. For this purpose two stringers or drawer rails may be used, their front edges being as far from the face of the legs as are the rails from the side and back. The upper drawer rail may be dovetailed at both ends into the tops of the legs, as shown in Fig. 292. If this takes more room than can well be spared from the depth of the drawer, it may be omitted, but it adds greatly to the stiffness of the table and is an excellent means of fastening on the top by the use of screws passing thru it.

The drawer rail, also called the fore edge, is long enough to partly overlap the side rails, into the lower edges of which it is gained so as to be flush with them, and may be fastened to them with screws, Fig. 293. The construction may be further strengthened by also doweling the end of this stretcher into the legs. If there are two drawers, the partition between them may be doweled or gained into these upper and lower stretchers.

If the legs are to be tapered or otherwise shaped, that should be done next. Then glue and assemble the end rails with their proper legs, taking care to see not only that the joints come up square, but that the legs are in the same plane. Finally assemble the whole, inserting, if necessary, a temporary diagonal brace to insure squareness, Fig. 294. When dry, clean up the joints. For the making of a table drawer, see above, p. 191.

To fit the drawer to its place, runners and guides, Fig. 295, must first be fastened in. The runners are in line with the drawer rail, and are glued and nailed or screwed to the side rails between the back of the lower stringer and the back posts. On top of them and in line with the inner face of the legs are the guides running between the front and back posts. Or the runner and guide may be made of one piece properly rabbeted out.

If there are two drawers, a double runner lies between, and is gained into the middles of the back rail and the stringer, and on it is a guide for both drawers, equal in width to the partition between the drawers. The drawers should run easily in their proper places. In order to insure this, the drawer should be slightly narrower than the opening which receives it. A little French chalk, rubbed on the sides and runners, makes the running smoother. Sometimes the opening for a drawer is cut out of the front rail, as in Fig. 296. In this case the drawer runners are supported between the front and back rails, into which they may be gained.

For the making of the table top see edge-to-edge joint, p. 172. Dress up the top to size, taking special pains with the upper surface. If the grain is crossed, use the veneer-scraper, Fig. 151, p. 92, then sand, first with No. 1, then with No. 00 sandpaper, finish the edges carefully, and attach to the frame.

For fastening the top to the table rails, several methods are used. The top may be screwed to the rails by the screws passing thru the rails themselves either straight up, Fig. 297, A, or diagonally from the inside, B, or thru blocks or angle irons, C, which are screwed to the inside of the rails, or thru buttons, or panel irons, D, which are free to move in a groove cut near the top of the rail. The last method is the best because it allows for the inevitable shrinkage and swelling of the top.

Chairs may be so simplified in form as to be possible for the amateur to construct. The two front legs and the rail and stretcher between them offer little difficulty because the angles are square.

The two back legs, may, for the purpose of simplification, be kept parallel to each other and at right angles to the seat rails between them, as in Fig. 298, A, and not at an angle as in B. The joining of the back will then offer little difficulty. The principal difficulties lie in the facts that for comfort and appearance the back of the chair should incline backward both above and below the seat, and that the back of the seat should be narrower than the front. By keeping at right angles to the floor the part of the back legs which receives the seat rail, the side seat rails will meet the back legs at a right angle in a side view, Fig. 298. The back legs should be slightly shorter than the front legs, as shown in D.

The second difficulty involves the making of inclined mortise-and-tenon joints, A, where the side rails fit into the legs. The making of these can be facilitated by laying out a plan of the full size and taking the desired angles directly from that. It is common to reinforce these joints with corner blocks glued and screwed in place as shown in A. If there are additional rails below the seat rails, the easiest way to fit them in place is first to fit and clamp together the chair with the seat rails only, taking pains to have all angles perfectly true, and then to take the exact measurements for the lower rails directly from the chair. The same method may be used for laying out a stringer between the lower rails.

If it is desired to bow the rails of the back, which are above the seat rail, this can be done by boiling them in water for 30 minutes and then clamping them over a form of the proper shape, with a piece of stiff sheet iron on the outside, as in Fig. 299. They should be thoroly dried in a warm place. Then the tenons may be laid out on the ends parallel to a straight-edge laid along the concave side. The chair bottom may be made of solid wood, either flat or modeled into a "saddle seat;" it may be covered with cane or rush, or it may be upholstered.

To upholster a chair seat, a frame should first be made of the shape shown in Fig. 298, C. The strips are about 2" wide and ½" thick with their ends half-lapped. The seat rails are rabbeted ½" deep and ½" wide to receive this frame, which should be ⅛" smaller all around than the place to receive it. The returns at the corners fit around the legs at ⅛" distance from them. This ⅛" provides space for the coverings. After the frame is fitted, it is covered with 3" webbing tacked firmly to the upper side. The webbing which goes back and forth is interwoven with that which goes from right to left. Over this is stretched and tacked (also to the upper side) a piece of unbleached muslin. A second piece of muslin is tacked to the back edge and part way along the side edges, leaving for the time the corners unfinished. In the pocket thus formed horsehair or other stuffing is pushed, care being taken to distribute it evenly and not too thick. When the pocket is filled, the muslin is tacked farther along the sides and more hair put in, until the front is reached, when the muslin is tacked to the front edge. The corners are now drawn in tight, a careful snip with the scissors parting them diagonally so as to lie in well. The partings may be turned down and tacked on the under side of the frame.

Finally the leather or other covering is stretched over the whole as evenly as possible. The corners should be left to the last, then clipped diagonally to the exact inside corner and the partings drawn down and tacked, as was the muslin. The superfluous leather may then be trimmed off, and the seat should fit in its place. Or the seat frame may be omitted, and the coverings tacked directly to the chair rails.

The balloon-frame house is a typical form of framed construction, Fig. 300. The essential parts of a balloon-frame are:

• 1. SILL, 4" × 8", which rests on the foundation.



• 2. BEAMS, 4" × 8", which rest on the cellar posts, 6"×6". (Not shown in illustration.)



• 3. FLOOR JOISTS, 2" × 8", which rest on the sill and beams.



• 4. CORNER POSTS, 4" × 6", with 2"×4" studs nailed to them.



• 5. STUDDING, 2" × 4", which stand 16" between centers.



• 6. WALL RIBBON, or girt, 1" × 8", which supports the upper story joists.



• 7. PLATES, two 2" × 4" nailed together, resting on studs.



• 8. RAFTERS, 2" × 6", which support the roof.



• 9. TIE-BEAMS, 2" × 6", which prevent the roof from spreading the walls. (Not shown in illustration.)



• 10. RIDGE-POLE, 2" × 8", against which the rafters butt.



• 11. BRIDGING, 2" × 2", which stiffens the floor joists.



• 12. SHEATHING, (1" thick), put on diagonally to brace the building. The rest is covering.



• 13. FLOORING, (See also Fig. 301.)
  
  
  
  
  
  • In flooring, Fig. 301, the boards are made narrow so as to reduce the size of openings at the joints when they shrink, and also to reduce the tendency to warp. They may be laid side by side as in the cheapest floors, or matched to close the joint. For difference between slash- and comb-grain flooring, see Fig. 55, p. 42.
  
  
  
  
  
  



• 14. BUILDING PAPER.



• 15. SIDING OR CLAPBOARDS, (See Fig. 301.) may either overlap without a joint or be rabbeted to fit. The best siding is rabbeted.



• 16. WATER-TABLE.



• 17. CORNER-BOARD.



• 18. FURRING.



• 19. SHINGLES.



• 20. LATHING.



• 21. CEILING, Fig. 301, consists of matched boards having a "bead" to disguise the joint and give a decorative effect.

TYPES OF WOODEN STRUCTURES

* For general bibliography see p. 4.

Chapter IX.