The Technique of FURNITURE MAKING

PLINTHS AND CORNICES Plinths

Plinths in traditional work were always project­ing, as distinct from recessed, the term itself meaning the lowermost square-shaped project­ing part of a base or column from the Greek phiallos, a brick. So-called recessed plinths are a comparatively recent development, occasioned no doubt by the necessity of evolving a base which did not require precision fitting in quantity work; moreover, such plinths are not so easily damaged and give toe room in tall cupboards and wardrobes. In the best work both types are made separately from the carcass and attached to the base with buttons, glue blocks, table plates or by pocket screwing. For accurate work the carcass should be made and assembled first, and the carcass base used as a guide for laying out the plinth.

Projecting plinths

The simplest form of projecting plinth is illus­trated in 195:1, 2 in which the front is plain mitred (195:2) or mitre rebated/rabbeted (195:3) and the corners glue blocked, with the back rail flush and lap dovetailed or tongued and grooved, or inset and housed/dadoed and blocked (195:4). Cross-bearers or stiffeners, where necessary, are housed and blocked or slip dovetailed, and a plinth moulding or capping is glue blocked to give adequate seating for the main carcass. Corner joints can be more elaborate, i. e. secret mitre or secret lap dovetailed, lap dovetails faced with solid wood (not thin veneer which will shadow the dovetails through in time) or tongued mitres, etc., but complex joints are rarely necessary, for the plinth itself is locked to the carcass and there is no side strain unless the furniture is roughly dragged over uneven surfaces. In assembling, shape the capping piece in one length, lay out the positions on the carcass base, bore screw holes for fastening, cut and glue the mitres and screw or cramp temporarily in position with scraps of paper under to prevent the surplus glue adhering. The front, sides and back rail of the actual plinth should then be assembled and glue blocked to the mitred cap moulding, making sure that the projection of the latter is equal all round. When dry the temporary screws in the cap moulding can be released, the plinth unit cleaned off and set aside for later assembly. If the plinth is to remain detachable then locating blocks which fit inside the cap moulding are screwed to the carcass base, and the carcass will then merely rest on the plinth. Traditional bracket plinths are shown in 195:5, 6 and 7, other forms in 195:8, and the construction of shaped plinths in 195:9, 10 and 11. All these plinths can be made up of veneered ply or laminboard, etc., but wood timber is better in case of rough treatment.

Recessed plinths

These can be assembled in the same way or set out by measurement, for the position is not highly critical. Side rails can be set in say 1/2 in (12.5 mm) but the front rail 3/4 in (19 mm) or more to give adequate toe room, while the back rail is usually flush with the carcass. If the carcass is solid wood, fastening will have to allow for the inevitable shrinkage, either with wood buttons or metal shrinkage plates, but plywood carcasses can have the plinths pocket screwed (195:13). A fairly common way of constructing these plinths in production-work is to lap dovetail the sides (195:12), but this is done not for reasons of strength but because it is simpler to mass produce dovetails than it is to mitre saw, shoot and glue block the plinth framing.

A variation often adopted in wardrobes and cupboards is to bring the carcass sides down to floor level and tongue an inset rail under the base (195:14). This is a modern rendering of the old method of mitring in a flush front rail and masking the through housing/dado of the cupboard floor with a moulding which was returned along the sides to simulate an independent plinth. The former method (195:14) is eminently practical and reasonable, but the older method of planted mouldings was merely a sham and never really practicable, for the side mouldings were invariably knocked off in time.

Plinth stools are constructed as described in Leg and frame construction, Chapter 22, p. 208, and are made up as already described.