The first thing that should claim the attention of the artistic
woodworker is the selection and preparation of his materials, commonly
known as the stock. The sculptor selects his marbles with the
greatest care. So should the cabinet-maker make sure that his woods
are taken from the right parts of selected timber and that they are
properly sawed and well seasoned. The importance of this cannot be
overestimated. Hard wood boards, cut from the sides of a tree, will in
drying, invariably curve across their grain. It is only those that are
cut from the centre to the outside of the tree that may be depended
upon to remain approximately true; for, after this cutting, the grain
runs directly through the thickness of the board, or nearly so. Boards
taken from timber in this way are said to be "quarter sawed"; those cut
by sawing through the logs from side to side, as is always done with
soft woods and often with hard woods, are said to be "plain sawed."
This is illustrated in the accompanying drawings.
_Quartered Oak._--In the case of oak, the quarter sawing not only
maintains a flat surface but greatly improves the appearance of the
stock when finished. The popularity of quartered oak for furniture may
therefore be said to be well founded, for it is the sincerest of woods.
It is as good as it looks.
[Illustration: Quarter sawed log]
Quarter sawing, however, is very largely confined to oak because the
appearance of the grain and the strength of most woods is far from
being improved by this method of cutting. Thus ash and gum wood and all
the softer woods sometimes used in furniture making are plain sawed.
We shall, therefore, generally find stock from these woods curved and
twisted badly so that it will be necessary, in selecting material for
large surfaces such as table tops, to pick out the straight parts for
these surfaces and save the remainder to be cut into the smaller pieces
which will always be needed. These pieces can be easily planed without
much loss of thickness.
[Illustration: End of quarter sawed board]
[Illustration: Plain sawed log]
[Illustration: End of plain sawed board]
_Kiln-dried Lumber._--This bending and twisting of the boards does not
take place as soon as they are sawed out of the log, but gradually
during the process of seasoning; and, unless the lumber is kiln-dried,
the more gradual the seasoning the less the bending. Lumber is
kiln-dried by stacking it, with air spaces left between the boards, in
steam-heated closets or kilns, where the process of drying is carried
on evenly though rapidly. Kiln-dried lumber, therefore, retains its
shape quite as well as that which is dried slowly in the lumber pile.
But whether kiln-dried or not, it should be allowed to remain in a
dry place as long as possible before using it so that it will have a
chance to change all that it is likely to and so lessen the subsequent
shrinking and warping. A good cabinet-maker never undertakes to make
furniture from stock that he does not know to be perfectly dry and well
seasoned, not only because unseasoned lumber is more likely to shrink,
warp, and crack, but also because it cannot be depended upon to hold
the glue, take varnish well, or respond readily to other methods of
finishing.
_Planing Down to a Flat Surface._--Since boards are seldom perfectly
flat, even if one has taken the greatest pains to select well-seasoned
stock, it will almost invariably be necessary to work them down to a
plane surface when they are glued up or joined together in any way.
To accomplish this result it is necessary to plan the arrangement of
the pieces in such a way that the concave of the bend shall fall on
the same side, as shown in the illustration, and thus provide for the
final working down with the least possible removal of stock. They can
be arranged on a level bench top or floor with the convex side down so
that they will lie as flat as possible. The boards should then be taken
out one by one and their edges should be carefully planed so that they
will match together in the position in which they are laid. It will
be necessary to take each board from its place and return it several
times in order that this matching may be made as perfect as possible.
The object of all this is to prevent the entire arrangement from
springing--_i. e._, from acquiring any new bend or twist when the parts
are glued up. In joining boards to form large pieces of glued-up work,
like table tops, it is customary to strengthen the joints by means of
dowel pins. Small table tops and similar work may be safely glued up
without dowelling.
[Illustration: Boards placed for planing to flat surfaces]
_Fastening Glued-up Work._ It will be readily understood upon a little
reflection that all plain glued-up work should be allowed to move
slightly upon the framework to which it is attached; for even after it
is well seasoned and well finished all woods will swell slightly in a
damp atmosphere and shrink slightly when the air is dry, the greatest
movement being across the grain. Solid table tops, therefore, should
never be fastened down firmly upon the framework with glue or with
screws, but should be secured by means of buttons screwed to the under
side of the top which travel in grooves cut in the framework and thus
allow for expansion and contraction. A drawing is shown to illustrate
the method of attaching the table-top buttons. Much of the warping and
splitting of furniture is due to the failure of the designer or maker
to observe this precaution.
[Illustration: Method of fastening table tops]
In planing up stock, whether it be a single piece or several glued
together as just described, the cabinet-maker planes off one side first
and then, using this side as the working face, gauges to the required
thickness and planes off the other side if necessary. If the work be
upon glued-up stock, it is well to plane off the projecting edges of
the concave sides first, as that is generally somewhat easier and may
be all the planing that will be necessary. If it be single pieces of
stock that need to be planed up, the natural twist or "wind" is first
planed out to a flat working face on one side before putting the plane
to the opposite side.
_The Surface Plate._--Planing to a flat surface requires some device
to guide the eye. If the surface be very uneven at first, a beginning
may be made in the planing without much assistance; but a point
will finally be reached when neither the unaided eye nor the hand
can determine whether or not a surface is flat. To determine this a
surface plate, as it is called, is needed. This consists of a block of
cast-iron, thick enough to prevent it from being bent--_i. e._, an inch
or more--and with a somewhat rough but perfectly flat surface on one
side. This surface is well chalked over. When the wood surface which is
being planed down is laid upon this chalked surface and slightly moved
it is readily seen that the highest places on the wood will become
marked with the chalk and so indicate to the cabinet-maker what parts
are to be removed. By making several tests of this kind he is able to
plane to a good flat surface.
[Illustration: Winding sticks]
_Winding Sticks._--If the amateur's workshop is not provided with
a surface plate, a simple means of testing for a flat surface is
by means of two narrow straight edges or "winding" sticks, placing
them on their narrow edges across each end of the piece, as shown in
the illustration, and sighting across their upper edges. The slight
projections in the surfaces of the board can be determined in this way
and planed off until the two top edges of the sticks are found to be
level. These winding sticks are simply wooden strips, accurately made,
with opposite faces parallel. Their dimensions may be 1 × 2-1/2 × 30
inches.
_Importance of True Surfaces._--It may be well to add that all this
care to produce flat and parallel surfaces is not merely for the
purpose of giving a good appearance to these surfaces. True surfaces
are necessary for the good of the work as a whole, for they form the
basis from which other surfaces are gauged and other parts "trued
up"--_i. e._, made square or otherwise geometrically correct. When the
main surfaces of a piece of cabinet work are properly shaped, all the
framework and other parts may be brought into line without bending
or twisting. All such strains should be religiously avoided in good
cabinet work. The natural curves, twists, or projections of the stock
used should be removed by the use of the proper tools and never be
strained to force any of the parts into their proper places or shapes.
Such efforts produce strains which are transmitted to other parts,
displacing them, causing new defects or a general failure of the parts
to support each other.
_A Systematic Plan of Work._--When the cabinet-maker undertakes to make
either a single piece of furniture or several pieces, he goes about
it in a very systematic way. Consulting his working drawing he makes
an accurate list of the different pieces that will be required. For
example, if he is to make a Morris chair he notes the fact that he will
need four legs or posts 2-1/2 inches square by 22-3/4 inches long, a
front rail and a back rail each 7/8 × 2-1/4 × 22 inches, two side rails
7/8 × 2-1/4 × 24 inches, and so on until the list of necessary parts is
completed. With this list in hand he makes a careful selection of the
lumber and prepares the pieces in the rough, allowing economically for
the necessary working waste. Economy of time and labour is also secured
by keeping together all parts on which similar work is to be done.
Thus, if several parts are to be sawed to the same width or fashioned
to the same curves, it is generally the best plan to work these parts
out together while the machines and tools are set for this purpose.
Such a plan not only saves time but, partially at least, it obviates
the danger of mistakes. It is important also to follow a systematic
order of work. All sawing to rough dimensions should be done before the
pieces are dressed to drawing dimensions, and the latter operations
should generally all be completed before laying out and cutting the
joints. As the work progresses toward completion great saving of time
and much comfort will result from keeping the completed parts in good
condition and so arranged that they can be easily assembled.