The Technique of FURNITURE MAKING

Dust boards/panels

These are a refinement fitted between drawers in carcass-work to protect the drawer contents from falling dust or displaced articles. They are now only used in the highest quality work. They can be solid, i. e. housed/dadoed in shelves which act as drawer rails, runners and dust boards, or of panelled construction with the front drawer rail and runners grooved for a thin ply sheet which was pushed in from the back and held in position by a stiffening back rail tongued into the runner grooves. Alternatively, they can be made up as a complete frame with ply panels and front and back drawer rails stub tenoned and runners housed into the sides. Muntins should be provided for wide carcasses which can also act as supports for upright divisions between the rails. A cheaper compromise often seen in Victorian furniture was to glue up the carcass with grooved front rails and runners, and push in a thin ply sheet which was left unsupported at the back; however, unless the ply is sufficiently rigid it is liable to sag in time and even foul the lower drawer.

Carcass assembly

Final assembly of the various component parts is the culmination of many hours of patient work and should never be hurried. A preliminary assembly in the dry state can be made but only to establish the direction of entry and the exactness of the fit. Dowelled components can be tried with spare dowel-pegs sanded slack (tight dowels should never be used as the suction in a tight hole can hold them immovable), and there can be no objection to fully seating tenons in order to check the shoulders, but dovetails only fit once and should not be entered beyond the halfway mark. If parts of the carcass can be glued, assembled and set aside to dry well before-hand, so much the better; but the squareness must be carefully checked, and if rails or fixed shelving are first glued to the carcass sides both carcass top and bottom should be partially entered to act as spacers. All joints should be clearly marked and readily distinguishable: tenons in chalk or soft pencil on the face of the rail, mortises also numbered on the face, sides marked in bold chalk lettering 'left' and 'right', 'top' and 'base', and other parts according to their location. These precautions might seem needless in straightforward assemblies, but all tenons look alike when covered with glue, and carcass sides have a habit of transposing themselves. A stout hammer and striking-block are necessary, also a long rule for checking opening or the spread of legs, long try-square, squaring-rod for the diagonals and a pair of winding-sticks. Before

the glue is mixed sufficient cramps/clamps should be assembled, tail slides set to the approximate postion and G-cramps/C-clamps likewise, with wood cross-bearers and softening pads for the cramps within reach. If hide glue is used then the component parts must be warmed slightly, but resin glues will set at ordinary room temperatures, giving plenty of time for methodical assembly. Dowelled constructions can have the pegs glued into one side, checked for length and the tops chamfered for easy entry.

Most old craftsmen only kissed the joints with glue, a dab on each tenon and perhaps a wipe across the shoulders, a brushful across the end of dovetails which were then smeared across the pin section, a trickle of glue run into the housings/dadoes. This was deliberate as it saved time applying and time in cleaning up, but the joints did fit and the glue was fairly thick; but with modern glues of low viscosity there is always a danger of starved joints if only a minimum of glue is used and the wood absorbent or the cramping/clamping pressure too great. Moreover, there is no comparison between this day and age and 80 years ago, for furniture must now withstand the ravages of central heating, and so every part should be glued thoroughly. If the surfaces are delicate then a wash coat of white shellac or cellulose can be applied up to but not over the glue-line to protect the surface, and a stick of chalk rubbed across the extreme edge of meeting joints will

Setting up carcasses

prevent a dark glue-line showing on pale woods—sycamore, holly, cherry, etc. The actual assembly should be done on a firm and level foundation and the work supported so that it does not sag under the weight of the cramps. Immediately assembly is completed it should be checked and rechecked for levelness and squareness. Openings should be checked with wood try-square (193:1 A) and set-square (193:lB), carcasses with the squaring-rod (193:2). If the diagonals show a difference of say 1/8 in (3 mm) (193:3) then the carcass will be
1/16 in (1.5 mm) out of square, which could be counted as negligible in a medium or large carcass, but greater disparities should be corrected by tilting the cramps (193:4A, 5A). Flat frames, drawers, etc. should be laid on a level foundation and checked for twist, and if the twist cannot be corrected by tilting the cramps then the high corner should be weighted down, packing up the other corner if necessary to force the twist in the opposite direction. If the carcass has to be cramped across the middle of the width, particularly with fixed shelvings in tight housings, heavy cross-bearers across the sides from front to back should be protected with a pad of newspaper (193:6) to apply the pressure where it is most needed. If a side or top tends to bow inwards it can sometimes be corrected by forcing it to the other extreme as in 193:7 (the distortion shown in 193:4, 6 and 7 is exaggerated for illustration purposes). A close watch should be kept that heavy cramps or cramping pressure do not bow the timber; if so it should be reinforced or the pressure eased a little. After checking from every angle the completed work should be left undisturbed until the glue has set, but heavy cramps should not be left in position longer than necessary or the carcass will tend to sag under the weight.