PART II.SIMPLE JOINERY.

PART II.SIMPLE JOINERY.Chapter VIII.Type Forms.

—This term in its broader meaning refers to the art of framing the finishing work of a house, such as doors and windows; and to the construction of permanent fittings, such as mantels, cupboards, linen presses, etc. Joinery as used herein refers merely to the putting together of two or more parts, called the members.

—Take into consideration the direction of the grain in planning the relative positions of the members. Make due allowance where shrinkage is likely to be considerable.

As far as possible, plan to have the members join face to face. Face sides are more likely to be true than are the other two surfaces and therefore the joints are more likely to fit properly.

Make all measurements from a common starting point, as far as practicable. Remember to keep the head of the gage, and the beam of the trysquare against one or the other of the faces, unless there should be special reasons for doing otherwise.

In practice it is sometimes advisable to locate the sides of a joint by superposition rather than by measurement.Laying out by superposition consists in placing one member upon another and marking upon the second member the width, thickness or length of the first.Fig. 143. Usually, it is found possible to locate and square with knife and trysquare a line to represent one of the sides of the joint. The first member is then held so that one of its arrises rests upon this line, and a point is made with knife at the other arris. The superimposed piece is then removed and a line made with knife and try-square—not thru the mark of the knife point but inside, just touching it.

Marking with superposition; marking membersFig. 143.Fig. 144.

Fig. 143.Fig. 144.

Fig. 143.

Fig. 144.

Where several members or parts are to be laid out, cut and fitted, it is of the utmost importance that the work be done systematically. System and power to visualize—that is, to see things in their proper relation to one another in the finished piece—make it possible for men to lay out and cut the members to the most intricate frames of buildings before a single part has been put together. Lay out duplicate parts and duplicate joints as suggested inChapter VII,Section 62. Where several joints of a similar size and kind are to be fitted, mark the different parts to each joint with the same number or letter as soon as fitted that no other member may be fitted to either of these.Fig. 144.On small pieces, such as the stool, it is possible to aid in visualizing by setting up the posts in the positions they are to occupy relative to one another, marking roughly, as with a penciled circle, the approximate location of the mortises, auger holes, etc. The members may then be laid on the bench and accurately marked without danger of misplacing the openings.

While the knife is used almost exclusively in laying out joints, there are a few instances in which a pencil, if well sharpened and used with slight pressure is preferable. To illustrate, suppose it is desired to locate the ends of the mortises in the posts.Fig. 144. To knife entirely across the surfaces of the four pieces and around the sides of each as would be necessary to locate the ends of the mortises, would injure the surfaces. Instead, pencil these lines and gage between the pencil lines. Those parts of the pencil lines enclosed by the gage lines—the ends of the mortises—may then be knifed, if desired, to assist in placing the chisel for the final cut.

In sawing joints in hard wood, the saw should be made to cut accurately to the line,Chapter II,Section 14. When working soft wood, beginners are often permitted to leave a small margin—about one thirty-second of an inch—between the knife and the saw kerf. This margin is afterwards pared away with the chisel.

Dado; checking dado depth and smoothnessFig. 145.Fig. 146.

Fig. 145.Fig. 146.

Fig. 145.

Fig. 146.

—A dado,Fig. 145, is made by cutting a rectangular groove entirely across one member into which theend of another member fits. Dadoes are cut across the grain of the wood; when similar openings are cut parallel to the grain, they are called simply, grooves. Dadoes are used in the making of shelving, window and door frames, etc.

—(1) Locate by means of the rule one side of the dado and mark its position with the point of the knife. (2) At this point, square a sharp line across the piece with knife and trysquare. (3) By superposition, locate and mark the second side. (4) Square these lines across the edges of the piece a distance equal to the approximate depth of the dado. (5) Set the gage for the required depth and gage between the knife lines on the two edges. (6) Saw just far enough inside the knife lines that the sides of the dado may be finished to the lines with the chisel.Chapter II,Section 14. Saw down just to the gage lines, watching both edges that the kerfs be not made too deep. (7) Chisel out the waste until the bottom of the dado is smooth and true.Chapter V,Section 47. Test the bottom as shown inFig. 146. Two brads are driven into a block having a straight edge until they project a distance equal to the proposed depth of the dado. (8) Pare the sides of the dado to the knife lines.Chapter V,Section 48. These sides might be finished in another way, by setting a wide chisel in the knife line and tapping it gently with a mallet. If care is taken the successive settings of the chisel need not show.

Where the dado is to be cut on a piece narrow enough that the saw may be made to follow the line accurately, it is considered better practice to saw accurately to the line.Chapter II,Section 14.

—Usually, stock for the two members of the cross-lap joint can be best planed to width and thickness in one piece. Place two sets of face marks on the piece, so that there shall be one set of marks on each member after they are separated. Two methods of making this joint are given. The first is safer for beginners; the second, because the members cannot be tried until the joints are completed, is an excellent test of one’s ability.Fig. 147.

Cross-lap jointFig. 147.

Fig. 147.

—First Method: (1) Square the two ends, measure from each of these the desired length of each member, square knife lines around, saw apart, finishing the ends square to the lines. (2) Measure from one end of each member the required distance to the nearer edge of the joint. Since the corresponding faces of the two members must be on the same side of the piece when the parts are put together, it will be necessary to lay off the groove of one member on the face and of the other member on the side opposite the face. If the joints are to be in the middle of each member but one measurement need be made.Chapter VII,Section 62. (3) Square sharp knife lines across at these points. (4) By superposition, locate and knife the second edge of each joint. (5) If the joints are to be in the middle of each member, before proceeding further, test to see that the lines have been laid out properly. If the members are placed side by side and the ends evened as in laying out in (2) above, the lines will of necessity correspond. Turnone of the members end for end and even the two ends; the lines ought still to correspond. If they do not, points marked midway between the corresponding lines will give the correct position for the new lines,Fig. 148. (6) Extend the knife lines just made across the two adjoining surfaces of each member. (7) Set the gage for the required depth and gage between the knife lines on these surfaces. Tho the groove on one member is laid out on the side opposite the face, do not make the mistake of holding the head of the gage against other than the face. (8) Saw accurately,Chapter II,Section 14, to the knife lines and to a depth indicated by the gage lines. (9) Chisel out the waste stock.Chapter V,Section 47. (10) Test as shown inFig. 149. A well made cross-lap joint is one in which the members can be put together with the pressure of the hands and which will not fall apart of their own weight.Fig. 150shows the results of “forcing a fit.”

Correcting marking linesFig. 148.

Fig. 148.

Checking the dado; warping because of forced fitFig. 149.Fig. 150.

Fig. 149.Fig. 150.

Fig. 149.

Fig. 150.

—Second Method.The two members are to be planed to width and thickness in one piece but are not to be separated until thegrooves have been laid out and cut. The grooves must be laid out by measurement only, since superposition is impossible. The positions of the grooves relative to the faces are, as in the first method, one on the face and one on the side opposite. The gaging for both is done from the faces.

—Frequently it becomes necessary to glue together a number of boards to make one wide enough to meet the requirements of the work in hand. A table top is a good illustration. A properly glued butt joint ought to be stronger than the natural wood.

When the wood is of sufficient thickness, the joint may be reinforced by means of dowels. The jointer should be used for planing the edges. It is extremely difficult to prepare edges for glue joints with the shorter planes. The jack plane should be used to rough off the edges and prepare them for the jointer.

Warped glued boardsFig. 151.

Fig. 151.

—(1) If the boards are in the rough, plane one surface of each true and out of wind. (2) Pencil the face marks upon these surfaces and indicate in some way the direction of the surface grain as well. Later, it will be necessary to plane both pieces at once in surfacing over the joints, and unless the parts are fitted with proper regard to the grain, it will be impossible to plane one without roughing up the other. Then too, the faces should be so selected that the warpage of one shall counteract the warpage of the other.Fig. 151shows the manner of placing the pieces. Observe the rings of growth.Chapter 12. (3) Joint one edge of each piece straight and square. The final plane strokes must be taken the fulllength of the board and the plane-iron must be set very shallow. Since the shrinkage is more at the ends than in the middle, sometimes the middles of long boards are planed just a shaving or two lower than the ends. (4) Place one of the boards in the vise, jointed edge up, and place the other board in position on it. Four tests are commonly used: First, placing the eye on a level with the joint and looking toward the light,Fig. 152; second, tapping the under board lightly to see if the top board “rocks”; third, sliding the top board lengthwise slowly to “feel” for suction; fourth, holding a straightedge as shown inFig. 153to see that the faces lie in the same plane. (5) Glue the edges,Fig. 154. Work rapidly but carefully. (6) Place the parts in the clamps and set away to dry; ten hours is usually long enough. Keep the faces as even as possible in applying the clamps. (7) When the glue has hardened the clamps may be removed, the surplus glue scraped off and the parts treated as one piece in squaring it up.

Visual inspection of joints; checking level of elementsFig. 152.Fig. 153.

Fig. 152.Fig. 153.

Fig. 152.

Fig. 153.

Glueing a jointFig. 154.

Fig. 154.

—Dowels are small wooden pins used in joining parts together. Dowels can be bought ready made in a variety of sizes. If desired short dowels may be made as follows: (1) Select straight-grained strong wood—beech, birch or oak; waste wood can usually be found that will do. (2) Split, not saw, these pieces roughly to square prisms. The blocks from which they are to be split should not be over eight or ten inches long to work well. (3) Plane off the irregularities, roughly rounding the pieces to size. (4) Point the ends slightly and drive the pieces thru a dowel plate.Fig. 155. The pegs should be driven thru the larger hole first. The holes of the dowel plate are larger in diameter on one side of the plate than on the other to give clearance to the peg as it is driven thru.

Driving a dowel through a dowel plate with a malletFig. 155.

Fig. 155.

The cutting edge of the hole is at the smaller diameter; place that side of the plate up. Never use a hammer as it would split the top of the peg and would ruin the cutting edge of the dowel plate should it strike it. Use a mallet, and when the peg is nearly thru finish by striking a second peg placed upon the head of the first.

—(1) Place the boards to be doweled side by side in the vise, the face sides out, and even the jointed edges. (2) Square lines across the two edges with knife and trysquare at points where it is desired to locate dowels. (3) Set the gage for about half the thickness of the finished board and gage from theface side across the knife lines. (4) At the resulting crosses bore holes of the same diameter as that of the dowel.

Dowels in one and holes in the other element of a jointFig. 156.

Fig. 156.

These holes should be bored to a uniform depth. Count the turns of the brace. One inch is a good depth for ordinary work. (5) Countersink the holes slightly, just enough to remove the sharp arrises. This removes any bur and allows a little space into which the surplus glue may run. (6) Cut the sharp arrises off the dowel, just enough to allow it to be started into the hole. (7) With a stick slightly smaller than the hole, place glue upon the sides of the hole, and drive the dowel in. A small V-shaped groove previously cut along the side of the dowel will allow the surplus glue to escape and thus prevent any danger of splitting the board. (8) Clean off the surplus glue, unless the members can be placed together before it has had time to set. (9) Saw off the dowels to a length slightly less than the depth of the holes in the second piece. (10) Trim off the sharp arrises.Fig. 156. (11) Glue the holes and the edge of the second board. (12) Put the two members in the clamps and set away until the glue has had time to harden.

Tenon, mortise and wedgeFig. 157.

Fig. 157.

—Fig. 157shows the tenon, the mortise in the second member into which the tenon fits, the mortise in the tenon and its key or wedge.

Examples of key formsFig. 158.

Fig. 158.

:—Keys are made in quite a variety of shapes. Some of the simple forms are shown inFig. 158. Where two or more keys of the same size are to be made, it is customary to plane all in one piece.(1) Plane a face side, a face edge, gage and plane to thickness. If there is more than one key, saw each to length. (2) Shape the remaining edge as desired. The lines AB and CD,Fig. 158, indicate the points at which measurements are to be made to determine the length of mortise in the tenon which is to receive the key. These lines should be laid off at a distance apart equal to the thickness of the tenon.

—(1) Measure from the end of the piece the length of the tenon, and mark with a knife point. Where tenons are to be cut on both ends of a piece, measurement is frequently made from the middle of the piece each way to locate the shoulders. Should there be any variation in the length of the piece from what it should be, this difference will then be equally divided at the ends. This is done when it is more important to have the distance between the shoulders of a definite length than that the tenons be of correct length.(2) Square knife lines entirely around the piece at the knife point mark. (3) Set the gage equal to the distance required from the face edge to the nearest edge of the tenon and mark on both sides, as far as the shoulder marks, and on the end. (4) Repeat, setting the gage from the face edge to the farther edge of the tenon. If the two members are of the same width and the tenon and mortise are to be equally distant from the face edge, both tenon and mortise should be gaged with the same settings. Frequently, the gage settings are obtained from the rule indirectly. The rule is laid across the piece and the width or thickness of mortise or tenon marked with the point of a knife blade,Fig. 159. The spur of the gage is then set in one of these points, the block being pushed firmly against the face; the thumb-screw is then fastened,Fig. 160. The second setting is obtained in a similar manner from the same edge or side. All the pieces are marked for the first width before resetting. (5) After having laid out the mortise in the tenon, rip to the gage lines and cross-cut to the shoulder lines, paring if necessary. (6) Slightly bevel the ends of the tenon.

Marking and measuring tenons and mortisesFig. 159.Fig. 160.

Fig. 159.Fig. 160.

Fig. 159.

Fig. 160.

—(1) From one end of the piece measure and mark with the knife point the respectivedistances to the two edges of the mortise. (2) Square lines across the face edge and the two broad surfaces at these points. (3) Set the gage equal to the required distance from the face edge to the nearer edge of the mortise and mark between the lines. (4) Set the gage equal to the required distance from the face edge to the farther edge of the mortise and mark between the lines. Make both gage lines on face side and side opposite as well. (5) Cut the mortises. First, bore a series of holes thru the mortise, using a bit somewhat smaller than the width of the mortise. Bore these holes so that they connect one with another. (6) Place the piece on a chiseling board and, taking thin cuts about half way thru, work from the middle of the mortise out to within one thirty-second of an inch of the knife and gage lines. (7) Reverse and chisel from the other side, finishing it; then chisel the first side out to the lines. Test the sides of the mortise with a straight edge—the blade of the chisel makes a good one—to see that they are cut straight.Fig. 161.

Checking the mortise's straightnessFig. 161.

Fig. 161.

—(1) Lay out the sides of the mortise for the key before the sides and shoulders of the tenons are cut. From the shoulder line of the tenon, measure toward the end a distance slightly less—about one thirty-second of an inch—than the thickness of the member thru which the tenon is to pass. This is to insure the key’s wedging against the second member. (2) Square this line across the face edge and on to the side opposite the face side. (3) Onthe top surface measure from the line just squared around the piece a distance equal to the width the key is to have at this point when in place.Fig. 158, A B. (4) Square a pencil line across the surface at this point. (5) In a similar manner, measure and locate a line on the opposite side, C D,Fig. 158. (6) Set the gage and mark the side of the mortise nearer the face edge on face side and side opposite. (7) Reset, and from the face edge gage the farther side of the mortise, marking both sides. (8) This mortise may be bored and chiseled like the one preceding. As one side of the mortise is to be cut sloping, a little more care will be needed.

Blind mortise and tenonFig. 162.

Fig. 162.

—Probably no joint has a greater variety of applications than the blind mortise-and-tenon,Fig. 162. It is of equal importance to carpentry, joinery and cabinet-making. The tenon shown has four shoulders; it is often made with but three or two.

—(1) Measure from the end of the piece the length of tenon, (see also directions for tenon,Section 89) and mark with the point of a knife. (2) Square knife lines entirely around the four sides at this point to locate the shoulders. (3) Lay the rule across the face edge near the end of the piece and mark points with the end of the knife to indicate the thickness of the tenon,Fig. 159. (4) With the head of the gage against the face side, set the spur of the gage in one of these marks, then fasten the set screw,Fig. 160.Gage on the end and the two edges as far back as the knife lines. When there are several tenons remember to mark all of them before resetting. (5) Set the gage in the other mark, the head of the gage being placed against the face side; then gage as before. (6) In a similar manner, place the rule across the face side, mark points with the knife for the width of tenon, set the gage to these points, and gage on the face and side opposite as far as the shoulder lines and across the end. The head of the gage must be held against the face edge for both settings. (7) Rip to all of the gage lines first, then crosscut to the shoulder lines, using back-saw. (8) The end of the tenon may be slightly beveled that it may be started into the mortise without tearing off the arrises of the opening.

—(1) From one end of the piece measure the required distance to the nearer and the farther ends of the mortise. Mark points with the knife. (2) Square lines across at these points. (3) Lay the rule across the face into which the mortise is to be cut and mark points with the knife for the sides of the mortise. (4) Set the gage as was done for the tenon, the spur being placed in the knife point mark and the head of the gage being pushed up against the face. Gage between the cross lines. (5) Reset from the same face for the other side of the mortise, and then gage.

If a mortise or tenon is to be placed in the middle of a piece, find the middle of the piece,Fig. 3,Chapter I,Section 1, and with the knife, place points to each side of the center mark at a distance equal to one half the thickness or width of the tenon or mortise. When several mortises ortenons of the same size are to be laid out and are to be equally distant from a face, the gage needs to be set but twice for all—once to mark the nearer edges and once for the farther edges of the tenon or mortise. Should there be several like members with like joints, the gage settings obtained from the first piece will suffice for all.

The importance of working from face sides or face edges only, cannot be overestimated. To work from either of the other two sides of a piece would make the joints subject to any variation in the widths or thicknesses of the pieces. To gage from the faces only, insures mortises and tenons of exact size no matter how much the pieces may vary in widths or thicknesses.

—Two methods of cutting mortises are in common use, (a) boring and chiseling, and (b) chiseling alone.First method: (1) Fasten the piece in the vise in a horizontal position. (2) Bore a series of connecting holes to the required depth,Chapter IV,Section 45, with a bit slightly smaller than the width of the mortise. (3) The sides of the mortise are next pared to the gage and knife lines, beginning at the auger holes and working with thin slices toward the lines. This method requires care and patience in order to get the sides of the mortise cut square to the surface. It is especially well adapted to large mortises from which much wood is to be removed.

Use of mortise grip; making the first mortise cutFig. 163.Fig. 164.

Fig. 163.Fig. 164.

Fig. 163.

Fig. 164.

—Second Method: (1) Clamp the piece which is to be mortised firmly to the bench top, using a hand clamp.Fig. 163shows a little device called a mortise grip. Tighten the vise screw and tap the grip with the mallet until it holds the piecesolidly. (2) Select a chisel of a width equal to that desired for the mortise. Stand well back of the mortise at one end or the other so as to be able to sight the chisel plumb with reference to the sides of the mortise. (3) Begin the cutting in the center of the mortise. Make the first cut with the bevel of the chisel toward you; reverse the bevel and cut out the wedge-shaped piece, w,Fig. 164. (4) Continue cutting in this manner until the proper depth has been attained, making the opening no larger at the surface than is necessary. (5) Set the chisel in a vertical position, bevel towards you, begin at the center and, taking thin slices, cut toward the farther end. Drive the chisel the full depth of the mortise each time, then pull the handle towards you to break the chip from the sides of the mortise. Cut to within one-eighth of an inch of the end of the mortise. (6) Reverse the piece, or your position, and cut in a similar manner to within one-eighth of an inch of the second end. (7) With the bevel side of the chisel next the end of the mortise pry out the chips once or twice as the cutting proceeds. (8) Chiselthe ends to the knife lines, carefully sighting the chisel for the two directions.Fig. 165suggests the order.

Suggested order of chiseling mortiseFig. 165.

Fig. 165.

—The miter joint is subject to various modifications. In the plain miter,Fig. 166, the ends or edges abut. They are usually fastened with glue or nails or both. The most common form of the plain miter is that in which the slope is at an angle of forty-five degrees to the edge or side.

Simple miter joint; clamping simple miter jointFig. 166.Fig. 167.

Fig. 166.Fig. 167.

Fig. 166.

Fig. 167.

—(1) Lay off the slopes (seeChapter I,Section 4). (2) Cut and fit the parts. To fit and fasten four miter joints, such as are found in a picture frame, is no easy task. Special miter boxes are made for this purpose which make such work comparatively easy. (3)Fig. 167shows the manner of applying the hand clamps to a simple miter joint. Whena joint is to be nailed, drive the nail thru one piece until its point projects slightly. Place the second piece in the vise to hold it firmly. Hold the first piece so that its end projects somewhat over and beyond that of the second; the nailing will tend to bring it to its proper position,Fig. 168. If a nail is driven thru from the other direction, care must be taken to so place it that it will not strike the first, or a split join will result.

Nailing a simple jointFig. 168.

Fig. 168.

—Dovetailed joints are so named from the shape of the pieces which make the joint.Fig. 169shows a thru multiple dovetail commonly used in fastening the corners of tool boxes. In hand made dovetails, the tenons are very narrow and the mortises wide, while in machine made dovetails, tenons and mortises are of equal width. Mechanics lay out the tenons without measurement, depending upon the eye unaided to give the proper size and shape. Sometimes dovetails are laid out to exact shape and size, the tenons being marked on both sides and ends. The mortises are marked with trysquare and bevel after one side of each has been marked by superimposing the tenons. In some kinds of dovetailing, such as the half-blind dovetail, the mortises are made first andthe tenons marked out from them by superposition.

Dovetail joint detailsFig. 169.Dovetail joint constructionFig. 170.

Dovetail joint detailsFig. 169.

Fig. 169.

Dovetail joint constructionFig. 170.

Fig. 170.

—(1) Square lines around each end to locate the inner ends of the mortises and tenons. These lines will be at a distance from the ends equal to the respective thicknesses of the pieces. (2) Determine the number of tenons wanted and square center lines across the end of the member which is to have the tenons. Place these center lines so that the intervening spaces shall be equal. (3) Measure along an arris and mark on either side of these center lines one-half of the desired width of the tenon. In fine hand made dovetails, the usual width for the narrow edge of tenon is scarcely more than one-sixteenth of an inch—the width of a narrow saw kerf. (4) Set the bevel for the amount of flare desired.Fig. 170shows measurements which may be used in setting the bevel. A flare stick may be made of thin wood and used instead of a bevel if desired,Fig. 170. (5) Mark the flares on either side of the center lines. Place the bevel so that the wide side of the tenon shall be formed on the face side of the piece. (6) Carry these lines back on each side of the piece as far as the lines previously drawn across these sides. (7) With a fine tenon saw rip accurately to the lines. Cut the kerfs out of the mortises, not out of the tenons. (8) Chisel out the mortises formed between the tenons andtrim up any irregularities in the tenons. (9) Set the tenons on end on the face side of the second member, with the face side just touching the cross line placed on the second member,Fig. 171, and mark along the sides of the tenons. (10) Square lines across the end to correspond with the lines just drawn. (11) Saw accurately to the lines, cutting the kerfs out of the mortises, not the tails. Chisel out the mortises for the tenons,Fig. 172. (12) Fit the parts together.

Marking along the tenons; chiseling out mortisesFig. 171.Fig. 172.

Fig. 171.Fig. 172.

Fig. 171.

Fig. 172.

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