starts out as a log that has been carefully selected and processed.
Green logs cannot be sliced because dry logs are too brittle.
All logs or log pieces must be soaked in hot water so that even
the internal fibers are moist enough to be sliced. They are
soaked in approximately 70 degree Centigrade water until the
are almost so heavy they will not float. The vats are then drained
and the logs or pieces of the logs are cleaned. They are then
ready to be put on a lathe or slicing machine and sliced.
of Veneer Slicing
There are three main types of veneer slicing equipment used commercially
rotary lathe in which the wood is turned against a very
sharp blade and peeled off in one continuous or semi-continuous
slicing machine in which the flitch or piece of log
is raised and lowered against the blade and slices of the log
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
part of the grain.
of these types of processes gives a very distinctive type of grain
depending upon the species. In any of these veneer slicing methods,
when the veneer is sliced a distortion of the grain occurs. The
knife blade as it hits the wood creates a "loose" side
where the cells have been opened up by the blade, and a "tight"
side. The coloring differentiations created by the tight and loose
side should not be confused with the "barber poling" effect
which takes place in certain wood in which the same piece of wood
appears to be dark or light depending on the way it is viewed. This
is caused by polarization of the grain wherein the grain is slightly
angled from the surface, and depending upon where the light source
is coming from, the grain is either in shadow or is penetrated by
the veneer is sliced, the veneer passes through a drying kiln to
bring its moisture content down to approximately 8%. Upon exiting
the dryer, bundles of veneer are made from sequences of veneer leaves.
Bundles generally include 24 to 32 leaves.
choice of materials and how those materials are used are decisions
you will make during the design process. When choosing veneers,
here are some key things to keep in mind:
of Quality Grade
Architectural Woodwork Quality Standards Illustrated,
published by AWI, provides three levels of quality: custom,
premium and economy. Each quality grade has direct implications
in the defects permitted in the veneer and the quality
of the panel products. The Quality Standards also describes
the method of gluing, splicing, sanding and backing panel
products. For more information on Selecting Veneers, click
of Veneer Species
Veneer species and method of slicing of the face and the
back of all panel products should be specified. It is
best that this information be either in the specifications
or on the drawings, but not in both locations. Many problems
can arise when a specification is not updated after the
drawings have been revised. It is not unusual to find
a specification calling for rift red oak when the design
drawings indicate another species, such as walnut. This
leaves the woodworker unclear on what to bid and the design
professional with a potential liability for additional
costs. For more information on veneer species, click
of Core Type
Consideration should be given to special requirements
such as fire resistance, water resistance, weight, flatness,
rigidity and strength required, defining the core which
best fits a project's needs. For more information on panel
cores, click here.
of Veneer Matching
There are three areas of consideration with respect to veneers,
all of which have been termed "matching." It should
be understood that these are very different considerations.
Confusion can sometimes result because of the use of the
single word, "matching," to describe these considerations.
The three types of matching are: