Carpentry for Boys

J >> J. S. Zerbe >> Carpentry for Boys

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In the latter (Fig. 202) four different moldings are used with the ogee
as the principal structure.

BASE EMBELLISHMENTS.--In like manner (Fig. 204) the base may have the
casement type first attached in the corner, and then the ovolo, or the
astragal added, as in Fig. 203.

[Illustration: _Fig. 200._]

[Illustration: _Fig. 201._]

[Illustration: _Fig. 202._]

STRAIGHT-FACED MOLDINGS.--Now let us carry the principle still further,
and, instead of using various type of moldings, we will employ nothing
but straight strips of wood. This treatment will soon indicate to you
that the true mechanic or artisan is he who can take advantage of
whatever he finds at hand.

Let us take the same cabinet front (Fig. 205), and below the cap (A)
place a narrow strip (B), the lower corner of which has been chamfered
off, as at C. Below the strip B is a thinner strip (D), vertically
disposed, and about two-thirds its width. The lower corner of this is
also chamfered, as at F. To finish, apply a small strip (G) in the
corner, and you have an embellished top that has the appearance, from a
short distance, of being made up of molding.

PLAIN MOLDED BASE.--The base may be treated in the same manner. The main
strip (4) has its upper corner chamfered off, as at I, and on this is
nailed a thin, narrow finishing strip (J). The upper part or molded top,
in this case, has eleven distinct lines, and the base has six lines. By
experimenting you may soon put together the most available kinds of
molding strips.

[Illustration: _Fig. 203._]

[Illustration: _Fig. 204._]

DIVERSIFIED USES.--For a great overhang you may use the cavetto, or the
apophyges, and below that the astragal or the torus; and for the base
the casement is the most serviceable molding, and it may be finished off
with the ovolo or the cymatium.

Pages of examples might be cited to show the variety and the
diversification available with different types.

SHADOWS CAST BY MOLDINGS.--Always bear in mind that a curved surface
makes a blended shadow. A straight, flat or plain surface does not, and
it is for that reason the concaved and the convexed surfaces, brought
out by moldings, become so important.

[Illustration: _Fig. 205._]

A little study and experimenting will soon teach you how a convex, a
concave or a flat surface, and a corner or corners should be arranged
relatively to each other; how much one should project beyond the other;
and what the proportional widths of the different molding bands should
be. An entire volume would scarcely exhaust this subject.

CHAPTER X

AN ANALYSIS OF TENONING, MORTISING, RABBETING AND BEADING

In the chapter on How Work is Laid Out, an example was given of the
particular manner pursued in laying out mortises and tenons, and also
dovetailed work. I deem it advisable to add some details to the subject,
as well as to direct attention to some features which do not properly
belong to the laying out of work.

WHERE MORTISES SHOULD BE USED.--Most important of all is a general idea
of places and conditions under which mortises should be resorted to.
There are four ways in which different members may be secured to each
other. First, by mortises and tenons; second, by a lap-and-butt; third,
by scarfing; and, fourth, by tonguing and grooving.

DEPTH OF MORTISES.--When a certain article is to be made, the first
consideration is, how the joint or joints shall be made. The general
rule for using the tenon and mortise is where two parts are joined
wherein the grains of the two members run at right angles to each
other, as in the following figure.

RULE FOR MORTISES.--Fig. 206 shows such an example. You will notice this
in doors particularly, as an example of work.

[Illustration: _Fig. 206._]

[Illustration: _Fig. 207._]

The next consideration is, shall the mortises be cut entirely through
the piece? This is answered by the query as to whether or not the end of
the tenon will be exposed; and usually, if a smooth finish is required,
the mortise should not go through the member. In a door, however, the
tenons are exposed at the edges of the door, and are, therefore, seen,
so that we must apply some other rule. The one universally adopted is,
that where, as in a door stile, it is broad and comparatively thin, or
where the member having the mortise in its edge is much thinner than
its width, the mortise should go through from edge to edge.

The reason for this lies in the inability to sink the mortises through
the stile (A, Fig. 207) perfectly true, and usually the job is turned
out something like the illustration shows. The side of the rail (B) must
be straight with the side of the stile. If the work is done by machinery
it results in accuracy unattainable in hand work.

[Illustration: _Fig. 208._]

TRUE MORTISE WORK.--The essense of good joining work is the ability to
sink the chisel true with the side of the member. More uneven work is
produced by haste than by inability. The tendency of all beginners is
to strike the chisel too hard, in order the more quickly to get down to
the bottom of the mortise. Hence, bad work follows.

STEPS IN CUTTING MORTISES.--Examine Fig. 208, which, for convenience,
gives six successive steps in making the mortise. The marks _a_, _b_
designate the limits, or the length, of the mortise. The chisel (C) is
not started at the marking line (A), but at least an eighth of an inch
from it. The first cut, as at B, gives a starting point for the next cut
or placement of the chisel. When the second cut (B) has thus been made,
the chisel should be turned around, as in dotted line _d_, position C,
thereby making a finish cut down to the bottom of the mortise, line _e_,
so that when the fourth cut has been made along line _f_, we are ready
for the fifth cut, position C; then the sixth cut, position D, which
leaves the mortise as shown at E. Then turn the chisel to the position
shown at F, and cut down the last end of the mortise square, as shown in
G, and clean out the mortise well before making the finishing cuts on
the marking lines (_a_, _b_). The particular reason for cleaning out the
mortise before making the finish cuts is, that the corners of the
mortise are used as fulcrums for the chisels, and the eighth of an inch
stock still remaining protects the corners.

THINGS TO AVOID IN MORTISING.--You must be careful to refrain from
undercutting as your chisel goes down at the lines _a_, _b_, because if
you commit this error you will make a bad joint.

As much care should be exercised in producing the tenon, although the
most common error is apt to occur in making the shoulder. This should be
a trifle undercut.

[Illustration: _Fig. 209._]

See the lines (A, Fig. 209), which illustrate this.

LAP-AND-BUTT JOINT.--The lap-and-butt is the form of uniting members
which is most generally used to splice together timbers, where they join
each other end to end.

[Illustration: _Fig. 210._]

Bolts are used to secure the laps.

But the lap-and-butt form is also used in doors and in other cabinet
work. It is of great service in paneling.

A rabbet is formed to receive the edge of the panel, and a molding is
then secured to the other side on the panel, to hold the latter in
place.

SCARFING.--This method of securing members together is the most rigid,
and when properly performed makes the joint the strongest part of the
timber. Each member (A, Fig. 212) has a step diagonally cut (B), the two
steps being on different planes, so they form a hook joint, as at C, and
as each point or terminal has a blunt end, the members are so
constructed as to withstand a longitudinal strain in either direction.
The overlapping plates (D) and the bolts (E) hold the joint rigidly.

[Illustration: _Fig. 211._]

[Illustration: _Fig. 212._]

THE TONGUE AND GROOVE.--This form of uniting members has only a limited
application. It is serviceable for floors, table tops, paneling, etc.
In Fig. 213, a door panel is shown, and the door mullions (B) are also
so secured to the rail (C). The tongue-and-groove method is never used
by itself. It must always have some support or reinforcing means.

[Illustration: _Fig. 213._]

[Illustration: _Fig. 214._]

[Illustration: _Fig. 215._]

BEADING.--This part of the work pertains to surface finishings, and may
or may not be used in connection with rabbeting.

Figs. 214 and 215 show the simplest and most generally adopted forms in
which it is made and used in connection with rabbeting, or with the
tongue and groove. The bead is placed on one or both sides of that
margin of the board (Fig. 214) which has the tongue, and the adjoining
board has the usual flooring groove to butt against and receive the
tongue. It is frequently the case that a blind bead, as in Fig. 215,
runs through the middle of the board, so as to give the appearance of
narrow strips when used for wainscoting, or for ceilings. The beads also
serve to hide the joints of the boards.

[Illustration: _Fig. 216._]

[Illustration: _Fig. 217._]

[Illustration: _Fig. 218._]

ORNAMENTAL BEAD FINISH.--These figures show how the bead may be used for
finishing corners, edges and projections. Fig. 216 has a bead at each
corner of a stile (A), and a finishing strip of half-round material (B)
is nailed to the flat edge. Fig. 217 has simply the corners themselves
beaded, and it makes a most serviceable finish for the edges of
projecting members.

Fig. 218, used for wider members, has the corners beaded and a fancy
molding (C); or the reduced edge of the stile itself is rounded off.

[Illustration: _Fig. 219._]

[Illustration: _Fig. 220._]

THE BEAD AND RABBET.--A more amplified form of work is available where
the rabbet plane is used with the beader. These two planes together
will, if properly used, offer a strong substitute for molding and
molding effects.

Fig. 219 has both sides first rabbeted, as at A, and the corners then
beaded, as at B, with the reduced part of the member rounded off, as at
C. Or, as in Fig. 220, the reduced edge of the member may have the
corners beaded, as at D, and the rabbeted corners filled in with a round
or concaved moulding (E).

SHADING WITH BEADS AND RABBETS.--You will see from the foregoing, that
these embellishments are serviceable because they provide the article
with a large number of angles and surfaces to cast lights and shadows;
and for this reason the boy should strive to produce the effects which
this class of work requires.

CHAPTER XI

HOUSE BUILDING

House building is the carpenter's craft; cabinet-making the joiner's
trade, yet both are so intimately associated, that it is difficult to
draw a line. The same tools, the same methods and the same materials are
employed.

There is no trade more ennobling than home building. It is a vocation
which touches every man and woman, and to make it really an art is, or
should be, the true aspiration of every craftsman.

THE HOUSE AND EMBELLISHMENTS.--The refined arts, such as sculpture and
painting, merely embellish the home or the castle, so that when we build
the structure it should be made with an eye not only to comfort and
convenience, but fitting in an artistic and aesthetic sense. It is just
as easy to build a beautiful home as an ugly, ungainly, illy
proportioned structure.

BEAUTY NOT ORNAMENTATION.--The boy, in his early training, should learn
this fundamental truth, that beauty, architecturally, does not depend
upon ornamentation. Some of the most beautiful structures in the world
are very plain. Beauty consists in proportions, in proper correlation
of parts, and in adaptation for the uses to which the structure is to be
put.

PLAIN STRUCTURES.--A house with a plain facade, having a roof properly
pitched and with a simple cornice, if joined to a wing which is not
ungainly or out of proper proportions, is infinitely more beautiful than
a rambling structure, in which one part suggests one order of
architecture and the other part some other type or no type at all, and
in which the embellishments are out of keeping with the size or
pretensions of the house.

COLONIAL TYPE.--For real beauty, on a larger scale, there is nothing
to-day which equals the old Colonial type with the Corinthian columns
and entablature. The Lee mansion, now the National Cemetery, at
Washington, is a fine example. Such houses are usually square or
rectangular in plan, severely plain, with the whole ornamentation
consisting of the columns and the portico. This type presents an
appearance of massiveness and grandeur and is an excellent illustration
of a form wherein the main characteristic of the structure is
concentrated or massed at one point.

The Church of the Madelaine, Paris, is another striking example of this
period of architecture.

Of course, it would be out of place with cottages and small houses, but
it is well to study and to know what forms are most available and
desirable to adopt, and particularly to know something of the art in
which you are interested.

THE ROOF THE KEYNOTE.--Now, there is one thing which should, and does,
distinguish the residence from other types of buildings, excepting
churches. It is the roof. A house is dominated by its covering. I refer
to the modern home. It is not true with the Colonial or the Grecian
types. In those the facade or the columns and cornices predominate over
everything else.

BUNGALOW TYPES.--If you will take up any book on bungalow work and note
the outlines of the views you will see that the roof forms the main
element or theme. In fact, in most buildings of this kind everything is
submerged but the roof and roof details. They are made exceedingly flat,
with different pitches with dormers and gables intermingled and
indiscriminately placed, with cornices illy assorted and of different
kinds, so that the multiplicity of diversified details gives an
appearance of great elaboration. Many of those designs are monstrosities
and should, if possible, be legally prohibited.

I cannot attempt to give even so much as an outline of what constitutes
art in its relation to building, but my object is to call attention to
this phase of the question, and as you proceed in your studies and your
work you will realize the value and truthfulness of the foregoing
observations.

GENERAL HOUSE BUILDING.--We are to treat, generally, on the subject of
house building, how the work is laid out, and how built, and in doing so
I shall take a concrete example of the work. This can be made more
effectual for the purpose if it is on simple lines.

BUILDING PLANS.--We must first have a plan; and the real carpenter must
have the ability to plan as well as to do the work. We want a five-room
house, comprising a parlor, dining room, two bedrooms, a kitchen and a
bathroom. Just a modest little home, to which we can devote our spare
hours, and which will be neat and comfortable when finished. It must be
a one-story house, and that fact at once settles the roof question. We
can make the house perfectly square in plan, or rectangular, and divide
up the space into the proper divisions.

THE PLAIN SQUARE FLOOR PLAN will first be taken up, as it is such an
easy roof to build. Of course, it is severely plain.

Fig. 221 shows our proposed plan, drawn in the rough, without any
attempts to measure the different apartments, and with the floor plan
exactly square. Supposing we run a hall (A) through the middle. On one
side of this let us plan for a dining room and a kitchen, a portion of
the kitchen space to be given over to a closet and a bathroom.

[Illustration: _Fig. 221._]

The chimney (B) must be made accessible from both rooms. On the other
side of the hallway the space is divided into a parlor and two
bedrooms.

THE RECTANGULAR PLAN.--In the rectangular floor plan (Fig. 222) a
portion of the floor space is cut out for a porch (A), so that we may
use the end or the side for the entrance. Supposing we use the end of
the house for this purpose. The entrance room (B) may be a bedroom, or a
reception and living room, and to the rear of this room is the dining
room, connected with the reception room by a hall (C). This hall also
leads to the kitchen and to the bathroom, as well as to the other
bedroom. The parlor is connected with the entrance room (B), and also
with the bedroom. All of this is optional, of course.

[Illustration: _Fig. 222._]

There are also two chimneys, one chimney (D) having two flues and the
other chimney (E) having three flues, so that every room is
accommodated.

[Illustration: _Fig. 223._]

ROOM MEASUREMENTS.--We must now determine the dimensions of each room,
and then how we shall build the roof.

In Figs. 223 and 224, we have now drawn out in detail the sizes, the
locations of the door and windows, the chimneys and the closets, as well
as the bathroom. All this work may be changed or modified to suit
conditions and the taste of the designer.

[Illustration: _Fig. 224._]

FRONT AND SIDE LINES.--From the floor diagram, and the door and window
spaces, as marked out, we may now proceed to lay out rough front and
side outlines of the building. The ceilings are to be 9 feet, and if we
put a rather low-pitched roof on the square structure (Fig. 223) the
front may look something like Fig. 225, and a greater pitch given to the
rectangular plan (Fig. 224) will present a view as shown in Fig. 226.

[Illustration: _Fig. 225._]

[Illustration: _Fig. 226._]

THE ROOF.--The pitch of the roof (Fig. 225) is what is called "third
pitch," and the roof (Fig. 226) has a half pitch. A "third" pitch is
determined as follows:

ROOF PITCH.--In Fig. 227 draw a vertical line (A) and join it by a
horizontal line (B). Then strike a circle (C) and step it off into three
parts. The line (D), which intersects the first mark (E) and the angle
of the lines (A, B), is the pitch.

In Fig. 228 the line A is struck at 15 degrees, which is halfway between
lines B and C, and it is, therefore, termed "half-pitch."

[Illustration: _Fig. 227._]

[Illustration: _Fig. 228._]

Thus, we have made the ground plans, the elevations and the roofs as
simple as possible. Let us proceed next with the details of the
building.

THE FOUNDATION.--This may be of brick, stone or concrete, and its
dimensions should be at least 1-1/2 inches further out than the sill.

THE SILLS.--We are going to build what is called a "balloon frame"; and,
first, we put down the sills, which will be a course of 2" x 6", or 2" x
8" joists, as in Fig. 229.

THE FLOORING JOIST.--The flooring joists (A) are then put down (Fig.
230). These should extend clear across the house from side to side, if
possible, or, if the plan is too wide, they should be lapped at the
middle wall and spiked together. The ends should extend out flush with
the outer margins of the sills, as shown, but in putting down the first
and last sill, space must be left along the sides of the joist of
sufficient width to place the studding.

[Illustration: _Fig. 229._]

[Illustration: _Fig. 230._]

THE STUDDING.--The next step is to put the studding into position. 4" x
4" must be used for corners and at the sides of door and window
openings. 4" x 6" may be used at corners, if preferred. Consult your
plan and see where the openings are for doors and windows. Measure the
widths of the door and window frames, and make a measuring stick for
this purpose. You must leave at least one-half inch clearance for the
window or door frame, so as to give sufficient room to plumb and set the
frame.

SETTING UP.--First set up the corner posts, plumbing and bracing them.
Cut a top plate for each side you are working on.

[Illustration: _Fig. 231._]

THE PLATE.--As it will be necessary in our job to use two or more
lengths of 2" x 4" scantling for the plate, it will be necessary to join
them together. Do this with a lap-and-butt joint (Fig. 231).

Then set up the 4" x 4" posts for the sides of the doors and windows,
and for the partition walls.

The plate should be laid down on the sill, and marked with a pencil for
every scantling to correspond with the sill markings. The plate is then
put on and spiked to the 4" x 4" posts.

INTERMEDIATE STUDDING.--It will then be an easy matter to put in the
intermediate 2" x 4" studding, placing them as nearly as possible 16
inches apart to accommodate the 48-inch plastering lath.

[Illustration: _Fig. 232._]

WALL HEADERS.--When all the studding are in you will need headers above
and rails below the windows and headers above all the doors, so that you
will have timbers to nail the siding to, as well as for the lathing.

CEILING JOISTS.--We are now ready for the ceiling joists, which are,
usually, 2" x 6", unless there is an upper floor. These are laid 16
inches apart from center to center, preferably parallel with the floor
joist.

It should be borne in mind that the ceiling joist must always be put on
with reference to the roof.

Thus, in Fig. 232, the ceiling joists (A) have their ends resting on the
plate (B), so that the rafters are in line with the joists.

BRACES.--It would also be well, in putting up the studding, to use
plenty of braces, although for a one-story building this is not so
essential as in two-story structures, because the weather boarding
serves as a system of bracing.

[Illustration: _Fig. 233._]

THE RAFTERS.--These may be made to provide for the gutter or not, as may
be desired. They should be of 2" x 4" scantling.

THE GUTTER.--In Fig. 233 I show a most serviceable way to provide for
the gutter. A V-shaped notch is cut out of the upper side of the rafter,
in which is placed the floor and a side. This floor piece is raised at
one end to provide an incline for the water.

A face-board is then applied and nailed to the ends of the rafters. This
face-board is surmounted by a cap, which has an overhang, beneath which
is a molding of any convenient pattern. The face-board projects down at
least two inches below the angled cut of the rafter, so that when the
base-board is applied, the lower margin of the face-board will project
one inch below the base.

[Illustration: _Fig. 234._]

This base-board is horizontal, as you will see. The facia-board may be
of any desired width, and a corner molding should be added. It is
optional to use the brackets, but if added they should be spaced apart a
distance not greater than twice the height of the bracket.

A much simpler form of gutter is shown in Fig. 234, in which a V-shaped
notch is also cut in the rafter, and the channel is made by the pieces.
The end of the rafter is cut at right angles, so the face-board is at an
angle. This is also surmounted by an overhanging cap and a molding. The
base is nailed to the lower edges of the rafters, and the facia is then
applied.

[Illustration: _Fig. 234a._]

In Fig. 234_a_ the roof has no gutter, so that the end of the rafter is
cut off at an angle and a molding applied on the face-board. The base is
nailed to the rafters. This is the cheapest and simplest form of
structure for the roof.

SETTING DOOR AND WINDOW FRAMES.--The next step in order is to set the
door and window frames preparatory to applying the weather boarding. It
is then ready for the roof, which should be put on before the floor is
laid.

PLASTERING AND INSIDE FINISH.--Next in order is the plastering, then the
base-boards and the casing; and, finally, the door and windows should
be fitted into position.

Enough has been said here merely to give a general outline, with some
details, how to proceed with the work.

CHAPTER XII

BRIDGES, TRUSSED WORK AND LIKE STRUCTURES

BRIDGES.--Bridge building is not, strictly, a part of the carpenter's
education at the present day, because most structures of this kind are
now built of steel; but there are certain principles involved in bridge
construction which the carpenter should master.

SELF-SUPPORTING ROOFS.--In putting up, for instance, self-supporting
roofs, or ceilings with wide spans, and steeples or towers, the bridge
principle of trussed members should be understood.

The most simple bridge or trussed form is the well-known A-shaped arch.

[Illustration: _Fig. 235._]

COMMON TRUSSES.--One form is shown in Fig. 235, with a vertical king
post. In Fig. 236 there are two vertical supporting members, called
queen posts, used in longer structures. Both of these forms are equally
well adapted for small bridges or for roof supports.

THE VERTICAL UPRIGHT TRUSS.--This form of truss naturally develops into
a type of wooden bridge known all over the country, as its framing is
simple, and calculations as to its capacity to sustain loads may readily
be made. Figs. 237, 238 and 239 illustrate these forms.

[Illustration: _Fig. 236._]

[Illustration: _Fig. 237._]

THE WARREN GIRDER.--Out of this simple truss grew the Warren girder, a
type of bridge particularly adapted for iron and steel construction.

This is the simplest form for metal bridge truss, or girder. It is now
also largely used in steel buildings and for other work requiring
strength with small weight.

[Illustration: _Fig. 238._]

[Illustration: _Fig. 239._]

[Illustration: _Fig. 240._]

THE BOWSTRING GIRDER.--Only one other form of bridge truss need be
mentioned here, and that is the _bowstring_ shown in Fig. 240.

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