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.
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 × 21⁄2 × 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 21⁄2 inches square by 223⁄4 inches long, a front rail and a back rail each 7⁄8 × 21⁄4 × 22 inches, two side rails 7⁄8 × 21⁄4 × 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.
GLUING
Necessity of Good Joints.—After the selection and preparation of the material for the stock, the next important general process that demands attention is gluing; for good cabinet work implies good glue and a knowledge of how to use it. Prepared glue, such as is sold in bottles, is unsatisfactory for work of any consequence. A good woodworker always has his own glue pot and sees to it that it may be made ready for use on short notice. The glue should be fresh, thin, and hot. It should be applied quickly in a warm room and the parts to which it is applied clamped up quickly before the glue chills. It is the glue which penetrates the wood that holds the parts together and not a layer of glue between the joined edges or surfaces. It is therefore evident not only that joints and surfaces should be well smeared with glue, hot and thin enough to be quickly absorbed, but also that the parts should be clamped up quickly while the glue is still hot so as to prevent any surplus from remaining in the joint. This is an additional reason for making close fits in all joints—in those which are to be glued up as well as in those which are not. It is a common fault of beginners to be satisfied with loose mortise and tenon joints, counting upon the glue to fill up the spaces. Much of the furniture found in the markets falls to pieces for the same reason. Such work should never be allowed to pass. It is based upon an entirely mistaken notion of the true office of glue and is nothing more nor less than a falsehood in wood.
