In woodworking, veneer refers to thin slices of wood, usually thinner than 3 mm (1/8 inch), that are typically glued onto core panels (typically, wood, particle board or medium-density fiberboard) to produce flat panels such as doors, tops and panels for cabinets, parquet floors and parts of furniture. They are also used in marquetry. Plywood consists of three or more layers of veneer, each glued with its grain at right angles to adjacent layers for strength. Veneer beading is a thin layer of decorative edging placed around objects, such as jewelry boxes.
Veneer is obtained either by "peeling" the trunk of a tree or by slicing large rectangular blocks of wood known as flitches. The appearance of the grain and figure in wood comes from slicing through the growth rings of a tree and depends upon the angle at which the wood is sliced. There are three main types of veneer-making equipment used commercially:
- A rotary lathe in which the wood is turned against a very sharp blade and peeled off in one continuous or semi-continuous roll. Rotary-cut veneer is mainly used for plywood, as the appearance is not desirable because the veneer is cut concentric to the growth rings.
- A slicing machine in which the flitch or piece of log is raised and lowered against the blade and slices of the log are made. This yields veneer which looks like sawn pieces of wood, cut across the growth rings.
- A half-round lathe in which the log or piece of log can be turned and moved in such a way to expose the most interesting parts of the grain.
Each slicing processes gives a very distinctive type of grain, depending upon the tree species. In any of the veneer slicing methods, when the veneer is sliced, a distortion of the grain occurs. As it hits the wood, the knife blade creates a "loose" side where the cells have been opened up by the blade, and a "tight" side.
Producing wood veneers Edit
The finest and rarest logs are sent to companies that produce veneer. The advantage to this practice is two fold. First, it provides the most financial gain to the owner of the log. Secondly, and of more importance to the woodworker, is this practice greatly expands the amount of usable wood. While a log used for solid lumber is cut into thick pieces, usually no less than 1 1/8 inches, veneers are cut as thin as 1/40 of an inch. Depending on the cutting process used by the veneer manufacture, very little wood is wasted by the saw blade thickness, known as the saw kerf. Therefore, the yield of a rare grain pattern or wood type is greatly increased, which in turn places less stress on the resource. Some manufacturers even use a very wide knife to basically "slice off" the thin veneer pieces. In this way, none of the wood is wasted. The slices of veneer are always kept in the order in which they are cut from the tree, and are known as flitches.
Types of veneers Edit
There are a few types of veneers available and each serves a purpose.
- A: Raw veneer has no backing on it and can be used with either side facing up. It is important to note that the two sides will appear different when a finish has been applied, due to the cell structure of the wood.
- B: Paper Backed veneer is as the name suggests, veneers that are backed with a paper. The advantage to this is it is available in large sizes, or sheets, as smaller pieces are joined together prior to adding the backing. This is helpful for users that do not wish to join smaller pieces of raw veneers together. This is also helpful when veneering curves and columns as the veneer is less likely to crack.
- C: Phenolic Backed veneer is less common and is used for composite, or man made wood veneers. Due to concern for the natural resource, this is becoming more popular. It too has the advantage of being available in sheets, and is also less likely to crack when being used on curves.
- D: Laid Up veneer is raw veneer, which has been joined together to make larger pieces. The process is time consuming and requires great care, but is not difficult, and requires no expensive tools or machinery. Veneers can be ordered through some companies already laid up to any size, shape or design.
There are a number of "patterns" common to veneered work. This refers to the way the veneers are laid up.
- A: Book Matched: where the veneers are opened from the flitch much like the pages of a book.
- B: Slip Matched: where the pieces are joined together in the order they come from the flitch, and have the same face kept up.
- C: Radial Matched: where the veneer is cut into wedge shaped pieces and joined together.
- D: Diamond Matched: where the pattern formed is diamond shaped.
Advantages of using veneers Edit
In addition to the obvious savings of our natural resources, many projects built using wood veneer would not be possible to construct using solid lumber. Due to expansion and contraction common to all wood products and caused by changes in humidity, many of the patterns and designs possible with veneers would self destruct, if attempted with solid lumber. The limitless designs done with marquetry and parquetry would also be impossible.
Buying veneers Edit
Wood veneers are typically sold by the square foot. With the ability to join veneers, even small pieces are usable, resulting in very little waste. Many sources sell small packets of veneers which are sequence matched, and are perfect for small projects. These make experimenting and practicing much more economical. It is also possible to buy plywood and other substrates with veneered faces for larger projects consisting of casework.
See also Edit
|Wikimedia Commons has media related to Wood veneer that may be added|
- Pro Woodworking Tips.com Veneering Index Information on Veneering
- DIYinfo.org's Wood Veneer Wiki - Practical information on working with veneers
- Decorative Wood Veneers Association Information on species, matching techniques and specifying of wood veneer.cs:Dýha