ELEMENTARY COURSE
IN
WOODWORK

DESIGNED FOR USE IN HIGH
AND TECHNICAL SCHOOLS

WITH
ONE HUNDRED AND THIRTY-FOUR ILLUSTRATIONS

BY
GEORGE ALEXANDER ROSS

INSTRUCTOR IN
WOODWORK AND PATTERNMAKING
LEWIS INSTITUTE, CHICAGO

FIRST EDITION

A. FLANAGAN COMPANY
CHICAGO :: NEW YORK

Copyright, 1901
by
A. Flanagan Company

PREFACE.

The character and object of this book is set forth on its title page. It is a manual designed principally for the practical assistance of students in elementary woodwork in the Lewis Institute.

The author has endeavored to present the subject in such a manner as to make simple the transition from the easier to the more difficult operations; the exercises have been selected after having had a thorough test covering a period of three years, and will be found practical in their application to the students in High and Technical Schools in elementary woodwork and turning.

Part one, the bench work, is intended to cover a period of eight weeks, two hours per day, and part two, wood turning, four weeks, two hours per day, thus making a course which will be found to touch the principal points in elementary work, at the same time giving practice in the uses of the tools most commonly used in carpentry, joinery and wood turning. Disston & Sons’ Handbook for Lumbermen has furnished many of the facts presented under “Care of Saws.”

It has been the author’s aim in this course to give just enough instruction in the work so that the student might be led to study out the problems for himself; by this means he is able to study the course of work that follows the second part of this book, i. e., Pattern Making.

A cursory perusal of the work will disclose many features which the author feels sure will commend themselves to instructors and others interested in this department of school work, and with the hope that these pages may prove a valuable aid to students and teachers alike, this work is presented to the public.

George A. Ross.

Lewis Institute, Chicago, 1901.

TABLE OF CONTENTS.

CARE OF SAWS, AND EQUIPMENT.

Elementary woodwork can be more readily learned from small pieces of wood than from large; so the exercises that are here given are of such dimensions that they can be easily handled in working out the problems.

Since it is by what we study and learn that we are able to do something else, the student in beginning this work should thoroughly familiarize himself with the tools, their names and uses, so that he may more readily understand their application in the work that follows.

The equipment for the general use of students in each bench locker is as follows:

The equipment of tools in drawer and under the care of individual students is as follows:

Tools, such as molding, beading, rabbeting, and plow planes are found in the tool room, and are issued to students on check when required.

Fig. 1.

[Fig. 1] shows the double bench equipped with rack, cam and quick acting vises, with the locker for the general tools and four drawers on each side of the bench with tools for the use of the individual student. Carpenters’ benches are usually about 33 inches high, while cabinet and pattern makers’ benches are from 2 inches to 4 inches higher.

The careful workman as a rule takes great pride in the condition in which his bench is kept; so the beginner should see that his immediate surroundings are kept in a neat, workmanlike manner, and with everything in proper place.

Care should be taken to protect the top of the bench from injury; it should never be marked by the chisel or cut by the saw. If chiseling has to be done on the bench, place the work on the bench hook or on a board, and in sawing use a bench hook such as is shown in [Fig. 2], that has a side lip that will protect the bench top.

Fig. 2.

The bench hook is made by students as an exercise, and is used to replace those hooks that have become worn out.

The material, which is delivered from the lumber yard in boards or planks, has to be cut up into lengths and widths suitable for the work to be done. The tools used for doing this cutting are the rip-saw and the cross-cut saw.

Now, a great amount of time can be lost in this work by the student, for the reason of his trying to do work with one tool when another should be used, and especially is this so in regard to saws. A saw will cut faster than a chisel in some places, and sometimes make the work as good if not better; so the student should learn to file and to keep a saw in just as good order as any other tool used.

We devote considerable space here to the saw, for we feel that the saw as one of the principal tools is often neglected, and is not used by students in their work as much as it should be. By a judicious use of this tool much time can be saved and a greater amount of ground covered than by trying to use a chisel or a jack knife in its stead.

Saws are either reciprocating or continuous in action; the first being a flat blade and a practically straight edge, making a plane cut, as in mill, jig, and sash saws; the latter either a circular or rotating disc, cutting in a plane at right angles to its axis (see buzz-saw in shop) or a continuous ribbon or band running on two pulleys, making a plane or curved cut with a straight edge parallel to their axis of rotation (see band-saw in shop).

Practically speaking, the teeth are a series of knives set on a circular or straight line, each tooth cutting out its proportion of wood, and kept from cutting more by the teeth on either side of it. Each tooth should cut the same amount and carry out the chips or dust, dropping it to the side or below the material being sawed. Different kinds of woods require teeth different in number, angle or pitch, and style of filing.

The perfect saw is one that cuts the fastest and smoothest with the least expenditure of power; to do this it is evident that each tooth should be so constructed and dressed as to do an equal proportion of the work, for if any of the teeth are out of line or shape they are not only useless themselves but a disadvantage to the others.

A saw tooth has two functions—paring and scraping. A slitting or rip saw for wood should have its cutting edge at about right angles to the fibre of the wood, severing it in one place, the throat of the tooth wedging out the piece.

Fig. 3.

The rip-saw, [Fig. 3], should be filed square across, and the front or rake of tooth should be at about right angles to the edge of the saw.

After jointing and setting, file one half the teeth from each side, which will give to the cutting edge of the tooth the slight bevel it should have for soft wood; for medium hard woods use a finer toothed saw, and file in the same manner; for the very hard, tough and cross-grained woods, use a saw still finer with the teeth filed slightly beveling, as ripping cross-grained stuff partakes a little of the nature of cross-cutting.

In all cases where ripping is done, the thrust of a saw should be on an angle of about 45 degrees to the material being cut, as shown in [Fig. 4]. This makes a shearing cut, an advantage that can be quickly demonstrated with an ordinary pocket knife, cutting any piece of soft wood.

Saws are designated by the number of points or teeth per inch, and the selection of a saw depends upon the character of wood to be worked. A rip-saw should have from 4 to 10 teeth per inch, the cross-cut saw from 6 to 16 teeth per inch. This includes the back-saw, it being filed the same as a regular cross-cut saw.

Fig. 4.

Fig. 5.

The harder the wood, the greater the number of teeth the saw should have.

We will now consider the cross-cut saw tooth in regard to rake or pitch; this being one of the most important features, too much care cannot be taken to have the correct amount of pitch for the duty required. To illustrate this. [Fig. 5] represents a board, across which we wish to make a deep mark or score with the point of a knife. Suppose we hold the knife nearly perpendicular as at B; it is evident that it will push harder and will not cut as smoothly as if it were inclined forward as at A. It follows then that the cutting edge of a cross-cut saw should incline forward as at [C, Fig. 6], rather than stand perpendicular as at [D, Fig. 7].

Fig. 6.

Fig. 7.

Too much hook or pitch and too heavy a set are very common faults, not only detrimental to good work but ruinous to the saw; in the first case, by having a large amount of pitch, the saw takes hold so keenly that frequently it “hangs up” suddenly in the thrust—the result, a kinked or broken blade; in the second, by having too much set, the strain caused by the additional and unnecessary amount of set is out of proportion to the strength of the blade, and it is broken in the same manner. The most general value of pitch used is 60 degrees, though this may be varied a little, more or less, to advantage, as occasion may demand.

In all cases the size of tooth depends largely upon the duty required; a long tooth has the demerit of being weak and liable to spring, but the merit of giving a greater clearance to the saw-dust. The throat space in front of each tooth must be large enough to contain the dust of that tooth from one stroke; the greater the feed the deeper the dust chamber required, or the more teeth. Where the teeth are fine the shape of the throat is of special interest.

The teeth of a hand-saw should be filed so true that on holding it up to the eye and looking along its edge, it will show a central groove down which a fine needle will slide freely the entire length. This groove must be angular in shape and equal on each side, or the saw is not filed properly and will not run true.

Fig. 8.

Fig. 9.

Fig. 10.

Fig. 11.

[Fig. 8] shows how the groove should appear on looking down the edge of the saw. The action should be such that the bottom of the cut or kerf will present the appearance as shown in [Fig. 9], and not as in [Fig. 10]; the cutting action is shown in [Fig. 11], the cutting being done with the outside of the tooth; the fibre of the wood is severed in two places, and the wood is crumbled out from point to point by the thrust of the saw.

The proper amount of bevel is very important, as is demonstrated by the [above figures], for if too much bevel is given the points will score so deeply that the fibres severed from the main body will not crumble out as severed but will be removed by continued rasping. This is true, particularly in hard woods, as they require less bevel, as well as pitch, than soft wood.

The next point to be considered is the bevel or fleam of the point. In [Fig. 12] the filer, as in all cases, files from the heel to the point; which is the only correct way.

Fig. 12.

The file is supposed to be perpendicular to the side of the saw in the vertical plane ([see Fig. 13]), at an angle of about 45 degrees in the horizontal plane, measuring from file line towards heel ([see Fig. 14]).

Fig. 13.

[Fig. 15] is a fair representation of many saws that we have seen owned by workmen; the result of owning such tools is shown in the poor work turned out by them.

Fig. 14.

As has already been said, the filing should be done from the heel of the saw toward the point. Many practical saw filers contend that this is wrong; that the filing should be done from the point of the saw toward the handle; but the only support they offer for this theory is that they do away with the feather edge that the filing from the heel of saws puts on the cutting face of the tooth. The feather edge is no objection, as the main part of it is removed when the teeth are side-dressed after the saw is set and sharpened.

Against the correctness of filing from point to handle may be cited the following objections:

Where a different angle of back is required (it should be remembered that that angle of face should be the same in nearly all cross-cut hand saws, and that angle of back governs angle of point) it will be found very difficult to obtain it without changing the angle of face of the tooth, and as the cutting duty is on the long side of the face, any change is, of course, of great influence. Again, to file from the point of the saw it is necessary to file with the teeth bent toward the operator. This will cause the saw to vibrate or chatter, a thing which not only renders good, clean, even filing impossible, but breaks the teeth off the file.

Fig. 15.

The setting of a saw is an important part of the work in keeping a saw in order, and should be done AFTER the saw has been jointed, and before filing.

The set should be uniform throughout, as the good working of a saw depends nearly as much on this as on the filing. One great mistake is often made in setting a saw, and that is that many try to put the set in the blade instead of in the tooth. The set should not go at the most lower than half the length of the tooth; by going lower it is liable to spring the body of the saw, if not break the tooth out.

Two methods may be given for setting saws. The first, or old method (employed before saw-sets were invented, and still used by old mechanics) is to take a hardwood block, lay the saw on it, and with a nail set and hammer set every other tooth on the side, then turn the blade over and repeat the operation on the teeth missed from the first side. It is needless to make any comment on this method when saw sets can be bought that are absolutely reliable in their operation.

The second method is to use the saw-set. Saw-sets are made in many styles, and can be bought at any hardware store.

Fig. 16.

Fig. 17.

Figs. [16] and [17] show two styles of saw-sets; much might be said in favor of each.

Saw clamps or vises used to hold the saw when filing can be bought (see [Fig. 18]), but a simple homemade vise can be put together by means of two pieces of board, one 3 feet 6 inches long and 6 inches wide, and one 2 feet 4 inches long and 6 inches wide. By fastening a piece 2½ inches thick about 10 inches from the top of each, to act as a fulcrum, and fastening a piece on each board at the top to act as jaws, and using a wedge at the bottom to tighten it up, a very serviceable vise is obtained ([see Fig. 19]).

Fig. 18.

Fig. 19.

To assist those not skilled in the art of filing, there is made a saw-filing clamp with a guide, of which a cut is here shown in [Fig. 20].

A few general rules may be observed in saw-filing: See that the file is held at the same angle throughout the operation. File every other tooth on one side, and when filed, reverse the saw and file the other teeth from the other side. For rip saws, place the file at right angles with the saw, and file the rake of tooth at right angles to the edge. After a saw is properly set and filed, lay it on a flat board and rub over the points of the teeth on the sides with an oil stone; this will regulate the set and insure smooth cutting, making the filing last longer. Should the saw not run true take another cut with the oil stone over the side toward which it leads.

Fig. 20.

A fast cutting cross-cut saw should have deep teeth.

Much useful information on saws can be obtained from a small book published and issued by Disston & Sons, Philadelphia, entitled “Hand Book for Lumbermen,” which, I believe, can be obtained on application.

The other tools used in this course will be taken up in order as they are used in the work.

EXERCISE NO. 1.

The following operations are designed to give the student a training in the use and care of the most commonly used carpenters’ and joiners’ tools. It is not intended that the student will be able to finish each exercise in one trial, as mistakes will be very common at the beginning, and it is advised that at least two or three trials may be given for the practice and training involved.

In [Fig. 21] is shown the working drawing (mechanical drawing) of a rectangular block of wood, and before we proceed to do the work required to finish this, we will study the drawing.

In order to represent solid figures with their three dimensions, length, breadth, and thickness, on a plane surface, i.e., a sheet of paper, we must have at least two drawings (projections), but to simplify the reading still further a third drawing is given, sometimes with additional drawings in the form of cross-sections.

To understand fully the principle upon which a working drawing is made, we will suppose that two transparent planes cross each other at right angles, making four right angles as shown in [Fig. 22], (these angles to be known as the 1st, 2nd, 3rd, and 4th angle of the co-ordinate planes), and respectively called the Horizontal and the Vertical planes.

Fig. 21.

Two of these angles are used in practice, the 1st and the 3rd; the most modern practice is to use the 3rd, although the 1st is still used in some manufacturing establishments and by some teachers.

Fig. 22.

We will take, first, the 1st angle, and compare it with the results obtained from the 3rd angle. We place the solid (exercise 1) in space in the 1st angle, and also place a similar one in the 3rd angle (see Figs. [23] and [24]).

Fig. 23.

Fig. 24.

By projecting the lines back on the vertical, and down on the horizontal plane, we obtain two views which are respectively the elevation on the vertical and the plan on the horizontal plane; to obtain the third view or end elevation, we have another plane placed perpendicular to planes H and V, as shown in Figs. [23] and [24], and the lines projected back from the left end; by opening or revolving these planes into one plane, as shown in [Fig. 25], we have a working drawing made in the 1st angle.

Fig. 25.

Referring to [Fig. 24], where we placed the solid in the 3rd angle, we project the lines up on the horizontal and to the front on the vertical plane, and by placing another plane at the end, perpendicular to the H and V planes, we obtain the third projection. Revolving the planes into one plane (i. e., a sheet of paper) [Fig. 26], we have the working drawing in the third angle. Compare the results obtained, and note the difference in the reading of the drawing.

In the first angle we see the plan is below the elevation, and in the third angle the plan is above; the pieces cut out of the exercise may also be noted in the end projection by the lines passing through the center of the exercise; in the first angle the line comes out full, the end being exposed, and in the third angle the surface is behind the full end and shows a dotted line.

Lines that are seen are shown as full lines.

Fig. 26.

Lines that are below a surface and are required in the reading of a drawing are shown as dotted lines.

The drawing, [Fig. 21], calls for a piece that is 8 inches at its longest, 2 inches at its widest, and 1 inch at its thickest point, and that may be designated thus: piece 8 inches × 2 inches × 1 inch finished.

For measuring, a standard rule 2 feet long that can be folded up is preferred. The rule is divided into feet, inches, ½ inches, ¼ inches, ⅛ inches, ¹/₁₆ inches, etc. On some rules will be found scales that can be used in measuring drawings that are drawn to scale. The drawing may be of any scale, using ⅛, ¼, 1, 1½, 3, or 6 inches to the foot.

Fig. 27.

The first thing to be done toward carrying out the work is to saw out a piece from the plank that is laid on the saw trestles ([Fig. 27]). Mark with a pencil the lines to be sawed; holding the rule in the left hand, and the pencil in the right, and placing the index finger of the left hand against the edge of the plank, as shown in [Fig. 28], draw both hands toward the body, thus marking out the piece lengthwise; then measure the length required and place the try-square ([Fig. 29]) against the edge of the plank, and draw a line along the blade through the point marked.

The piece should be marked out larger than the finished exercise so that there will be stock enough in the piece to perform the operations required, say 8½ inches × 2½ inches, the plank being thick enough to provide for the work on the sides.

Fig. 28.

Having “laid out” the piece on the plank, take the rip-saw and hold it as shown in [Fig. 30]: saw down the line, taking care that the “kerf” is square to the side of the plank; then take the cross-cut saw, and saw across the line marked. Hold the cross-cut saw as in [Fig. 30].

After having cut the piece from the plank take the jack-plane and put it in good condition for work. A sectional view of the Bailey Iron Plane is shown in [Fig. 31], and the parts are as follows:

• A—Plane-Iron.
• B—Cap Iron.
• C—The Iron Lever.
• D—Thumb piece and Cam.
• E—Screw which acts as a fulcrum when the thumb piece is pushed into position.
• F—Thumb screw by which the Plane-Iron A is regulated for any thickness of shaving.
• G—Lever which is in contact with Plane-Iron.
• H—Screw which holds the iron bed piece in place.
• I—Bed piece.
• K—Lever.

Fig. 29.

The plane-iron should be ground on the grindstone if nicked or rounded.

To grind the plane-iron it should be held in the hand as shown in [Fig. 32].

Fig. 30.

Fig. 31.

Apply the iron to the stone, as indicated by dotted line [A, Fig. 33]; then raise it until the proper angle is reached, a position indicated by full lines B.

Fig. 32.

Move the tool gradually from one side of the stone to the other. See that there is plenty of water on the stone. The tool should be held during the operation so that it revolves toward the person grinding. The tool thus held is not so liable to have a “wire edge” as it is if held on the stone while it is revolving away from the operator.

Fig. 33.

The “whetted” edge should never be ground away unless the plane-iron is in very poor condition.

The grinding is complete when the bevel reaches the cutting edge,—a condition which can readily be determined by holding the finger along the flat side of the iron and having the light fall in the proper direction; a thin bright line will be seen which will determine whether the iron is ground enough. The plane-iron is shown before it is ground in [Fig. 34], and [Fig. 35] shows it after it is ground.

Fig. 34.

Fig. 35.

Fig. 36.

To whet or sharpen the iron an oil stone is used. Oil stones are of different grades; a stone of medium hardness is best, as it will cut a little faster and leave a fairly smooth edge; whereas if the stone be hard much time is required to whet the iron, but it leaves a smoother edge. A coarse stone leaves a rough edge. Use oil that will not become gummy on the stone. Several good artificial stones have lately come on the market which give good service. To sharpen the iron, apply it as shown in [Fig. 36, 1 and 2], and move it back and forth as indicated in [Fig. 37].

Fig. 37.

Many persons sharpen their plane irons as indicated in [Fig. 38]; at first thought this may appear to be right, but many mechanics of long experience sharpen the “iron” as indicated in [Fig. 36]. This method gives a stronger edge, which is not so liable to get nicked when the iron strikes a knot or a hard spot in the work.

Fig. 38.

Great care should be taken to avoid giving the iron a rocking motion on the oil stone, as this will round the edge and the iron will not be any sharper than it would be if it were in the form shown in [Fig. 39].

Fig. 39.

Fig. 40.

After having whetted the bevel side of the iron sufficiently, turn the iron so that it will rest perfectly flat on the stone, as shown at [3, Fig. 36], and whet it in this position; this will remove the “wire edge.” Care should be taken to see that the iron is not raised in whetting the flat side; if raised as in [Fig. 40] the cutting qualities of the edge will be injured.

The iron is now sharpened. Replace the cap iron, keeping it back from ¹/₆₄ to ¹/₃₂ of an inch from the cutting edge; then place it in position and fasten it; look down the face of the plane and see that the edge protrudes far enough to cut the required thickness. The adjustments are made by the thumb screw F and lever K, [Fig. 31].

Fig. 41.

Place the block already sawed on the bench against the bench stop, [Fig. 41], and then follow the method here given for planing a piece to the given dimensions.

FIRST.

Plane one side true and mark (0) for the “working face.” (A surface is said to be true when it is perfectly straight across; straight lengthwise, and free from twist).

“Side” here used means one of the wider surfaces in distinction from the narrower surface, the edge.

Methods for testing the surface with parallel strips, etc., will be shown by the instructor.

SECOND.

Plane one edge perfectly straight lengthwise, and square to the face side. Mark this edge for the “working edge”; use the try-square, [Fig. 29], to test the work.

Fig. 42.

THIRD.

Set the gauge, [Fig. 42], to the width given in the drawing, and gauge a line from the face edge on both sides; then plane to the gauge lines.

Fig. 43.

In using the gauge see that it is held as shown in [Fig. 43], and push away from the body, having the pressure on the gauge as shown by the line [A, B, Fig. 44]. This will keep the head of the gauge close to the work. Do not try to mark a line by holding it as in [Fig. 45], with the spur at right angles to the work, as it will generally follow the fibre of the wood and a crooked, ragged line will be the result. By holding it as shown in [Fig. 43] (and gently letting the spur touch the work, going over it once or twice until the line is of the desired heaviness to work to) a clear, clean-cut line will be obtained.

Fig. 44.

Fig. 45.

FOURTH.

Set the gauge to the given thickness (see drawing for dimension) and gauge a line on both edges from face side; then plane to gauge lines. This, if done correctly, will finish the four surfaces. It is sometimes necessary that the ends of a piece of work should be finished smooth; the method of procedure is as follows:

Mark (from one end about ¹/₆₄ of an inch) a knife line all around ([see Fig. 46]), placing the head of the try-square against the face edge and the face side only; then take a small block and put behind the exercise as shown in [Fig. 47], fasten in the vise, and plane to the knife lines. This block will save the corners from breaking.

Fig. 46.

Fig. 47.

To finish the other end measure the length and mark as on the first end. Then if the piece is too long to plane, saw off near the line, using the back-saw as shown at [Fig. 54], and then finish with the plane to the lines.

Fig. 48.

In planing care must be taken to see that the plane is held firmly on the work to secure a true surface. A rocking motion must be avoided. In order to get the best results see that the front of the plane is held down with the left hand, also pressing down and forward with the right hand at the same time, and at the end of the stroke lift the front of the plane as shown in [Fig. 48]; never let it drop as in [Fig. 49].

A proper and an improper position to stand while planing is shown by Figs. [50] and [51].

In planing the edge if it is higher on one side than the other, move the plane over to the high side and plane it down. [Fig. 52] shows the position of the plane.

Fig. 49.

Fig. 50.

Fig. 51.

After the block is planed true and to the correct dimensions, lay out the lines across the face at the left hand end shown in the drawing and square the lines down the depth on the edges; then set the gauge and mark around the end and notch on both edges. Beginners will find it a little difficult at first to saw a perfectly clean line so as to secure a sharp corner; by cutting notches with a knife point as shown at [Fig. 53], it will be easy to secure sharp corners. Place the back-saw, [Fig. 54], in the notch, hold it tightly against the flat side, and saw down to the desired depth, removing the portion from the end with the rip saw ([see Fig. 55]).

Fig. 52.

Fig. 53.

To remove the portion between the sawed lines take the chisel, [Fig. 56] (the same directions to be used for grinding and sharpening a chisel as are used for the plane-iron), pare lightly (about half through the width of the piece), cut down to the gauge line, and then turn the piece around and finish from the other side, leaving a straight surface at the bottom of the notch. Be careful not to take too heavy a cut, for the chisel will be hard to guide if the workman has to exert his whole strength to push it through the wood. The chisel has a tendency to go down into the work if the flat side is not used as a guiding surface; this side, if kept in contact with the solid wood, will insure a straight surface, and consequently accurate work.

Fig. 54.

Fig. 55.

Fig. 56.

The lining on the exercise is made with the gauge for the lines running parallel with the edge, with the square and the knife for the lines at right angles to the edge, and with the bevel, [Fig. 57], and the knife for the oblique lines. Figs. [58] and [59] give methods for finding the angle of 45 degrees, which is the angle that is used for the oblique lines.

Fig. 57.

Too much attention cannot be given to the operations in this exercise, for in all work that requires material to be prepared, carelessness in detail and inattention to methods, etc., will always appear in the finished work.

Fig. 58.

Fig. 59.

EXERCISE NUMBER 2.
HALVED JOINT.

Fig. 60.

When two pieces of timber of equal thickness cross each other and the joint is to be flush, i. e., the pieces when joined are to form a flat surface, they are halved together; or, to put it in another way, a piece is taken out of each half its thickness and as broad as the piece which is to cross it, thus allowing the one to drop into the other, as shown in [Fig. 60]. The working drawing is shown in [Fig. 61].

To make this piece of work, refer to methods and operations given for the preparation of material in the first exercise.

Fig. 61.

Special results are sought for by specific methods in this exercise. Exercises that are not finished (by the methods given) as they should be, are thrown out as not coming up to the requirements and fall short of the object for which they are designed.

The drawing shows two pieces of wood of given dimensions crossing each other at right angles and halved together, making a flush joint. Requirements: The pieces to be of the exact length, breadth, and thickness called for, fitted closely on both sides, each piece to be exactly in the center of the other, and both sides smoothed off and perfectly flat when finished; the ends of the pieces to be planed square, and the ends of the halving to be fitted from the saw. Methods: After sawing out a piece (long enough to make both pieces, allowing for work on the ends), plane the piece by the methods given for planing in the first exercise; then saw it across in the center and proceed to lay out the pieces so that the face side of each piece will come on the same side; this means that the halving is cut out of the face of one piece and the back of the other ([see Fig. 60]).

Fig. 62.

It will be well to consider this problem of laying out work as a problem in arithmetic. The pieces called for in the drawing are 5½ inches long, 1½ inches wide, and 1 inch thick. The piece that crosses comes exactly in the center. Therefore we have a problem like this: 5½″ -1½″ = 4″, which is the difference between the length of one piece and the breadth of the other; but the piece comes in the center, and so we take the difference of the length, which is 4″, and divide it by 2. 4″/2 = 2″, which will give the distance from the end up to the first edge of the cross-piece. As all measurements have a beginning somewhere, we mark a line near the end of the piece as shown in [Fig. 62], and from this line we lay off the distance to the cross-piece, marking with a knife point the position of the edge. Then we lay off the width of the cross-piece, which is 1½″, leaving the distance to the other end 2″, the same as at the first end.

Fig. 63.

Having found the position of the edges of the cross-piece, we mark a line across the work (using a knife and a square); then mark the lines down the edges. Now taking the gauge, we gauge from the face side of each piece the depth required. Then we cut a notch inside the lines with a knife, as shown at [Fig. 53], place the piece on the bench hook, saw down to the gauge lines with the back-saw (position shown in [Fig. 54]), and remove the portions to be taken out by the methods given for the notch in the first exercise.

Then plane the ends of each piece perfectly square to the face side and face edge.

An exercise that was made by a careful student and one that was made by a careless student are shown at [Fig. 63], revealing the final results of careful as against careless work.

Having cut out the center pieces and finished the ends we fit them together, seeing that the surfaces come flush; then smooth off the surfaces, being careful not to cut too much off the ends, for this will round the surfaces and thus spoil the work. Sharp tools are essential to good work.

Lines drawn in their proper places, and then cut to, will give the results sought for in fitting.

EXERCISE NUMBER 3.
MORTISE AND TENON.

When beams or pieces of wood stand square with each other, and the strains are also square with the pieces and in the plane of the frame, the most common junction is the mortise and tenon.

A mortise is an opening, which may be square or oblong, intended to receive the tenon, and which may go into the work only a short distance, or may go all the way through. Where it goes only part way through it is called a blind mortise, and where it passes all the way through, a through mortise. A tenon is a projection on the end of a piece and fits into the mortise. The tenon usually has two shoulders formed by cutting away the sides, and should be about one third the thickness of the piece.

Fig. 64.

There are a number of different styles of this joint and methods of fastening, which we will consider later in our work.

The working drawing shown in [Fig. 64] gives the dimensions of the pieces, the material of which is to be worked out in one piece, as directed in the previous exercise, and then cut up into lengths suitable for the exercise. The student should commence work on a piece with a full understanding of what is required to be done in order to finish the work as called for, and not try to make any kind of work do in order to proceed to the next task.

Notice what is required in this exercise:

1st. That the pieces be perfectly straight and square.

2nd. That the tenon piece be exactly in the center of the mortise piece, and that the angles be right angles or “square.”

3rd. That the work be laid out systematically, with the lines in their proper places.

4th. That the tenon be made altogether with the saw.

5th. That the mortise be cut out with the hand mortising chisel.

6th. That the tenon fit into the mortise, and not be squeezed.

7th. That the joint fit closely, and that the work be finished off smoothly on the sides, with all the corners sharp and the end of the pieces sawed square.

The following methods if carried out will help the student to finish the work as required.

It will be unnecessary to repeat hereafter the method of planing, as the student by this time should have learned to plane the pieces properly to dimensions.

After the material has been planed, mark the piece to the desired lengths as shown in [Fig. 65], and saw off the pieces square on the ends. Use the knife to mark the lines. In sawing, care must be taken to saw on the right side of the line, for the saw will cut out its own thickness and reduce the length of the piece that much if the piece is sawed on the wrong side of the line.

Fig. 65.

Leave the tenon piece about ⅛ inch longer than the drawing calls for so that the tenon will protrude through and be finished off even with the mortise piece.

Fig. 66.

Proceed to lay out the work. Take the mortise piece, which is 6 inches long, and mark the distance from one end (6″-1½″ = 4½″.) 4½″ / 2 = ⁹/₂ × ½ = ⁹/₄ or 2¼″; locate the first point on the face edge; then measure from this point the width of the tenon piece, which is 1½″. Through the points just found draw the lines square to the face side. Place the square against the face edge and mark (on the opposite edge on the corner), a small cut for both lines ([see Fig. 66]) and square from the face side across the edge; lay the piece aside; take the tenon piece and point off the distance from the end of the piece to the shoulder, and mark across the face and back, using the square and the knife in marking. Prepare the shoulder lines for the back-saw, as shown in [Fig. 53], taking care that the notch is cut on the right side of the line.

Take the gauge and set it to the distance from the face side to the first side of the mortise, and gauge the lines for the mortise on both edges; gauge the lines for the tenon. (This is for a single gauge.) Take the mortise chisel, [Fig. 67], and make a mark from this line ([see Fig. 68]), which will give the thickness of the tenon and the width of the mortise; set the gauge out to the width and gauge the rest of the lines.

Fig. 67.

Fig. 68.

Take the rip-saw and saw down the outside of the lines on the tenon piece the length required; cut off the sides with the back-saw. In sawing split the line so that the tenon will be as thick as the mortise is wide. This means that half the line is to be left on the work. Fasten the mortise piece in the vise, putting a piece below to keep it from going down when cutting.

Place the mortise chisel about the center of the mortise; hold it vertically, and with the mallet drive the chisel down into the work; release the chisel and make a new cut, keeping the flat side of the chisel towards the end to which the mortise is being cut. [Fig. 69] shows how the cutting should be done.

Having reached the end, turn the chisel around, and cut towards the other end in the same manner. (Where the mortise goes through it will be unnecessary to take the chips from the first side.)

Fig. 69.

Fig. 70.

Turn the piece over, and repeat the operation on the other side, when the chips can be easily removed. Proceed to test the work; see that the mortise is straight on the ends. Generally the student will leave the ends rounding as shown in [Fig. 70]; this, if the tenon is driven into the mortise, will squeeze the edges out of true ([Fig. 71]) and leave an opening on the ends of the mortise, as shown in [Fig. 72].

Fig. 71.

Fig. 72.

Care should be taken to avoid this fault in this exercise. (A mortise gauge such as a joiner uses is shown in [Fig. 73]; it has two spurs, one being adjusted by the thumb screw at the end of the shank. We will use a mortise gauge in our work later on.)

Fig. 73.

After the pieces have been cut, put them together, having the face sides together, and finish smoothly.

EXERCISE NUMBER 4.
KEYED MORTISE AND TENON,
WITH BRACE.