Veneer

Cutting veneer

Veneer has traditionally been produced in two ways. Saw-cut veneer is sliced from the side of a squared timber baulk or a plank with a large circular saw or a horizontal frame saw; Ellis (1908) gives saw-cut veneers as running from four to sixteen sheets to the inch. Jones (1920) explains that large circular saws built for this work are really a broad, flat wheel with short lengths of saw blade bolted around the rim, and argues that saw-cut veneer takes a finer finish than veneer sliced with a knife, though a knife wastes far less wood as sawdust between each sheet. Once cut, veneer is dried and inspected; defects such as knots can be cut out and a sound patch let in, and the sheets are then sorted into those good enough for a visible facing and those fit only to be used, unseen, in the core of a panel.

Preparing and laying veneer

Both the veneer and the solid timber it will be glued to, called the groundwork, need preparing first. Hasluck (1897) describes taking the saw marks off a sawn veneer with a fine toothing plane, a plane with a finely serrated blade that scores the surface so glue can grip it, while the groundwork is roughened with a coarser toothing plane for the same reason. He also notes that using less glue is better, since a heavy coat is more likely to work its way through to the surface and spoil the job.

The traditional way of pressing veneer down is called hammer veneering, though the tool used, the veneering hammer, does not strike the work at all. Hayward (1950) describes gluing two sheets, one straight after the other, with the grain of each running across the grain of the groundwork, then working the veneering hammer over the surface to squeeze surplus glue and trapped air out from the centre towards the edges. Ellis (1908) adds that the face of the veneer is first wetted with hot water, to counter the swelling that the wet glue on its back would otherwise cause. Not every pattern can be laid this way: Jones (1920) warns that marquetry and other built-up patterns made from many small pieces cannot be laid with a veneering hammer, because the moisture in the glue makes the pieces swell unevenly and buckle, or in his word, cockle.

Where a veneer covers a narrow surface, such as a door frame or a mirror surround, and crosses the grain direction of the frame beneath it, Joyce (1987) calls this cross veneering; it can be glued with traditional hide glue worked in with a hammer or a curved clamping block called a caul, or clamped under a veneer press using a modern cold-setting synthetic resin glue.

Matching the grain

Because a single log can be sliced into many consecutive sheets, veneer is often arranged so the grain pattern of neighbouring sheets lines up. Hasluck (1897) describes matching two or four veneers around a joint so their grain forms a symmetrical figure, and book matching, a related practice, opens adjacent sheets like the pages of a book so their figure appears as close to a mirror image as the log allows; since this leaves half the sheets showing their rougher, loose face outward, that face has to be cut as cleanly as possible. Jones (1920) notes that in the best work the colours of different veneers were sometimes deepened or lightened with stain before polishing, to draw a pattern of several woods together.

Modern engineered veneer

Veneer is not only a decorative facing. Laminated veneer lumber is a structural material built up from many layers of veneer glued together with the grain running the same way through the whole thickness, rather than crossed as in plywood. The USDA (2021) traces early work on it to the 1940s, when it was developed to produce high-strength aircraft parts from Sitka spruce veneer; the end joints between individual sheets of veneer are staggered along the length of the finished piece, so no single weak point runs across it.