The Technique of FURNITURE MAKING

Sliding glass doors

The general principles are the same as for sliding wood doors. Figures 236:1, 5 show a pair of glass doors which can be either 3/16 in (5 mm) or 1/4 in (6 mm) plate, depending on the overall size, and with all edges rounded and polished. These slide in twin channels or grooves at top and bottom of the carcass opening, either worked in the solid or with one wide groove divided by an inset hardwood strip; or various channel sections can be fitted (236:2, 3 and 4). Figure 236:2 is the standard brass channel velvet lined for easy running, as bare metal alone gives a somewhat hard and gritty action; 236:3 is a metal channel with inset plastic strip, and 236:4 a plastic or fibre channel. The last is somewhat clumsy in appearance but offers little friction. All these channels are let in flush, and in every case the top channel is approximately 3/8 in (9.5 mm) deep and the base channel 1/4 in (6 mm) deep, for assembly is effected by pushing the doors up into the top channel and letting them fall into the base. In effect, therefore, the overall height of the doors will be the exact size of the opening plus 1/4 in (6 mm) for the bottom channel, and a bare 1/8 in (3 mm) for the top. As these measurements are fairly critical it is rarely safe to order by measurement alone; moreover the carcass may not be truly square, therefore it is a wise precaution to cut sheets of plywood or hardboard, test that they enter and run freely in the channels and use these as templates for purchasing the glass.

An improved sliding action for glass doors is shown in 236:5, 6 which offers definite advantages. Top and bottom metal channels are provided, also a sprung U section for the bottom of the doors and a metal carriage (236:6A) with inset metal or nylon balls. As this carriage is free to travel independently it must be longer than the width of the door or the latter will tip off, and assuming a 3 ft (914 mm) wide carcass opening with two doors, then the top and bottom channels will be 3 ft (914 mm) long, the U channel two lengths 18 in (457 mm) long, and the carriage two lengths 2 ft 2 in (660 mm) long. Here again the doors are lifted up into the deeper groove of the top channel and allowed to drop into the lower. This fitting is an improvement on the older type of carriage (236:7) in which small vulcanite wheels were used.

Handles for glass doors

Cheaper doors have oblong finger-grips of about 1/8 in (3 mm) thickness glass cemented to the plate (237:2), but undoubtedly the better method is a cut finger-grip (237:1) which is run in with a grinding-wheel. Alternatively, thin sections of wood, preferably built up of several sheets of veneer to overcome shrinkage, can be glued to the glass with Araldite cement (237:3, 4), and in the writer's experience have proved satisfactory in use, although obviously they will not stand hard knocks.

Dustproofing glass doors

As with wood doors the carcass sides should be grooved to form a dust seal, while the actual gap between the doors can be closed with an available bristle fitting as shown in 236:8, 8A. The bristle assembly clips over the edge of the glass and requires no other fixing. The impact of a free-running glass door against the sides of a carcass can be fairly considerable, and the grooves should be lined with velvet, or small felt, leather or rubber buffers can be fitted to absorb the shock.

It should be stressed that, as with all types of flush sliding door, if the carcass is made up of laminboard, particle board, etc., the hardwood covered edges should be wide enough to accommodate all the groovings, or the ragged core will be visible when the doors are slid open. This hardly matters if the grooves are cased in, but in any case the tongues of the edgings should be placed well away from the grooving, and care in laying out will be amply repaid.