Sawing The Dovetails
After marking out the pins on the drawer sides, we proceed with the next operation, that is, sawing the dovetails ready for chopping out the waste material. The drawer side is taken and firmly secured in the bench screw and sawn as at ; it is most important that the saw kerf is kept inside
the line which has been scratched by the marking awl. See , where the dotted line represents the gauge line and the outside lines indicate the scores of the marking awl. Failure to observe this condition will result in faulty dovetailing, and it will also prove the necessity for using a finely-toothed and thin-bladed dovetail saw.
To cut out the waste wood (or core), the usual procedure is to saw away the half-dovetails as at . With care, this can be accomplished with the dovetail saw, thus avoiding unnecessary labour and the use of the paring chisel.
After sawing, the drawer side is placed flat upon the bench, one end in contact with the bench to prevent the drawer side from slipping away; a chisel (preferably bevelled edged) of suitable width is now taken and a small channel is cut as at A, . The method of cutting this channel is shown in the same illustration. The chisel-cut is started about 1⁄8 in. from the gauge line; the cut is made right up to the gauge line, which (when gauging) was made 1⁄32 in. deep so as to cut the cross fibres of the timber. A small piece of waste wood will therefore come away as at A.
The object of cutting this small channel is so that, when the chisel is held vertically on the gauge line and struck with the mallet, the chisel will have no tendency to force its way backward and overshoot the gauge line. The waste or core is now removed by holding the chisel approximately vertical and applying sufficient power to drive it half-way through the timber. The drawer side is now turned over, the operation repeated, and the core pushed out. Care must be exercised whilst cutting away the core to ensure the chisel being held nearly perpendicular; if too much lead (or bevel) be given, a faulty and undercut dovetail will be the result. Undercut dovetails prevent a proper grip of the glue; they give a weak joint, and often cause the face of the drawer side to be splintered whilst driving up the joint. If it be necessary to ease one or two shavings from off the drawer side whilst fitting the completed drawer in the carcase, the joint will show a greater gap as each succeeding shaving is removed.
In common work, especially in soft timbers, many workers allow the pins of a drawer back to run through the sides about 1⁄16 in. and hammer down the pins of the dovetail. This is called "bishoping the dovetails," and is unnecessary if the work be properly made and fitted.
An alternative method of dovetailing is that of cutting the dovetails first, as shown at . Four or six drawer sides are placed in the vice and the dovetails are sawn at one operation. A little lead (or bevel) from front to back is given whilst sawing, and if this method be used care must be taken to see that the parts of the drawer sides which will be on the inside of the completed drawer are towards the worker, or the lead will be given to the dovetails in the wrong direction.
Fig. 283.—Cutting several Dovetails at once.
After sawing the dovetails in this manner the sides are placed in their respective positions on the drawer fronts or backs, and marked with a pounce-bag or by using the saw-blade method. The pins are then cut in the usual way, care being taken that the saw kerf be on the outside of the marks, otherwise the pins will finish too slack to engage with the tails.
Next: Frame Dovetails