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Flexible veneer sheets at Veneer Technologies, which says it has one of the largest face plants,
on site, to provide domestic and exotic species, with an assortment of backers.
Image courtesy of Veneer Technologies, Inc.
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Thinly sliced, continuously rolled or sheeted, applied by machine or manual craftsmanship, veneer production and the appreciation of veneers predates the modern era. Romans veneered furniture, and Egyptians veneered sarcophagi. Germany’s Armin Wiblishauser claims credit for developing the first continuous rolls of veneer edges in 1973, and by 1976 his Furwa Furnierkanten was producing them in a factory setting.
The wide range of hardwood veneer sources is amply demonstrated at the redbookonline.com (see list below). Suppliers’ sites found there offer technical background and a wealth of informative tips for woodworkers.
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Image courtesy of Veneer Technologies, Inc.
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Veneer production is both art and science. Depending on the intended application and desired grain, it will be obtained either by “peeling” the trunk of a tree or by slicing the large rectangular blocks of wood known as flitches. Grain patterns are set by slicing through the growth rings of the tree at varying angles.
After logs are debarked, veneer is peeled from the log, and then dried. Three main types of veneer-making equipment are used: the rotary lathe (wood is turned against a very sharp blade and peeled off in one continuous or semi-continuous roll); the slicing machine (a flitch or piece of log is raised and lowered against a blade, yielding veneer which looks like sawn wood, cut across the growth rings); or a half-round lathe (a wood log can be turned to expose the most interesting parts of the grain).
Distinctive GrainsEach slicing process yields a distinctive grain, as do tree species. Veneer slicing tends to distort the grain, the knife blade as it hits the wood creating a “loose” side where cells are opened up by the blade, and a “tight” side.
Oakwood Veneer, Troy, MI, selling 180 species, describes the common veneer patterns at its site:
Book Matching — Alternating pieces of veneer are flipped over so they face each other as do the pages within a book. This creates a pleasing, symmetrical pattern.
Slip Matching — Veneer slices are joined in sequence without flipping the pattern; in straight grain wood, joints aren’t obvious.
Pleasing Match — Veneer is matched by color, not grain pattern.
Random Match — Done with lower grades of veneer, the leaves may be of varying width, colors and grains.
There are some caveats to finishing veneers, summarized in a white paper by Thomas Weaver for the Hardwood Plywood & Veneer Association. (It is also posted along with other helpful veneer information at the Website of Veneer Technologies, Inc., Newport, NC.) Weaver notes that in book-matched veneers, since every other piece of veneer is turned over (as in the pages of a book) to create a symmetrical grain pattern at the splices, a “tight” and “loose” wood grain face is alternated in the adjacent pieces of veneer. The different faces may accept stain and reflect light differently, causing a noticeable color variation across the panel.
This blotchy appearance that sometimes occurs on book-matched panels is referred to as the “barber pole” effect. Proper sanding and use of washcoats prior to staining, advises Weaver, will help avoid the variances when staining facing book-matched veneers.
A video of exotic wood veneer manufacturing is at the Website of Tree Frog Veneer, a unit of Chemetal. Tree Frog distributes veneers from Italy-based Alpi, some using engineered, or composite, wood technology, a manufacturing process that creates a wood veneer that is more consistent in color and structure than natural wood veneers. Alpi uses either plantation-grown Poplar from Italy or Ayous (Obeche) from Cameroon (West Africa). The logs are cut into individual veneer sheets, dyed, shuffled, glued and formed in a hydraulic press into a veneer “log” that is sliced again in a different direction, and finally bonded to a 10 mil paper backer sheet.
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