| Air-dried lumber- Lumber
that was dried, usually outside, to an equilibrium moisture content with the air it was
exposed to. Any lumber below 30% MC is classified as air dried. Construction grade is
around 19% MC and in southern Ontario the relative humidity is usually between 50 to 60 %
which lumber will equalize to moisture content to between 8 to 14% MC. Annual growth rings- The layer of growth that a
tree puts on in one year. The annual growth rings can be seen in the and grain of lumber.
Birds-eye figure- A figure on wood,
usually maple and a few other species. The figure is composed of many small rounded areas
resembling a birds eye. The figuring is most common on plain and rotary sawn lumber.
Board Foot- A form of wood measurement,
where one board foot equals the volume of a board I inch thick, 12 inches wide, and 12
inches long.
Bookmatch- A term in veneering or
sawing, where successive pieces of veneer, or boards, from a flitch, or log, are arranged
side by side. A properly done bookmatch will resemble a mirror image of the opposite side.
Other names are sisters, butterflied and mirrors.
Bound water- water found within the cell
wall of wood.
Bow- A defective piece of lumber that
has warped along its length.
Brad- A small finishing nail up to
1" long.
Burl- Bulges and irregular growths that
form on the trunks and roots of trees. Burls are highly sought after for the incredible
veneer they yield and are used in turning as well.
Butt Joint- A woodworking joint where
the edges of two hoards are placed against each other.
Cambium- The live, actively growing,
layer of a tree. The cambium is one cell thick and resides between the sapwood and the
phloem. It repeatedly divides itself to form new wood end causes the tree to grow and
expand. It is the layer that becomes either bark or wood and lies dormate in the winter.
Case Hardening- A defect in the lumber
caused by improper drying. Case Hardening is caused when a board is dried too fast. The
outer layers in a case hardened board are compressed while the inner layers are in
tension.
Cell- The smallest, microscopic,
structure in wood.
Check- A lumber defect caused by uneven
shrinking of the wood during drying. A checked board has splits which develop lengthwise
across the growth rings.
Clear- A board which is free of defects.
Common Grade Lumber- Lumber with obvious
defects.
Compound Cut- An angled cut to both the
edge and face of a hoard.
Crook- A lumber defect where there is an
edgewise warp effecting the straightness of the board
Crotch- In lumber, a piece of wood taken
from the fork of a tree. Crotch Veneer is highly valued for its figuring.
Cup (cupping)- A defect in the lumber
where the face of the board warps up like the letter U.
D2S- Lumber that has been dressed on two
sides.
Deciduous- Generally trees that have
broad leaves that are shed in the fall. Usually it is a hard wood.
Defect- An irregularity found in a board
that lowers its strength and value. Common defects are knots, staining, checks, etc..
Edge Joining- Smoothing and squaring the
edge of a board so that it can be glued up
squarely to another piece.
Equilibrium moisture content(EMC)- When
the level of moisture in a board is equal to the moisture in the surrounding air.
Face Veneer- High quality veneer that is
used for the exposed surfaces on plywood.
Flat-sawn Lumber- A method of sawing
lumber where the log is cut tangential to the growth rings.
Free Water- Moisture found in the cell
cavities of wood.
Girth- The distance around a tree; the
circumference.
Grain- The size, alignment, and color of
wood fibers in a piece of lumber
Green Lumber(Live) - Freshly cut lumber
that has not had time to dry. Lumber that is above 30% moisture content.
Heartwood- The dead inner core of a
tree. Usually much harder and darker than the new wood.
Infeed- The direction a work piece is
fed into a blade or cutter.
Kiln- In lumber drying, a kiln is a room
or building where temperature, moisture, and the air circulating are controlled to dry
wood.
Latewood- The part of a trees annual
growth ring that is formed later in the season
Linear Foot- A measurement of the length
of a board.
Lumber- Logs which have been sawn,
planed, and cut to length.
Lumber-Core Plywood- Plywood where thin
sheets of veneer are glued to a core of narrow boards. Lumber-core plywood differs from
regular plywood in that regular plywood is made up of successive layers of alternating
grain veneer.
Lumber ruler- A tool resembling a ruler
with a handle at one end and a hood at the other which is used to calculate the board
footage of a piece of lumber.
Medium density fiberboard (MDF)- A
special type of tempered hardboard characterized by a very fine, smooth finish. MDF is
used in cabinet making.
Mill-run- Lumber that is in varying
widths and grades.
Moisture
Content(MC)- A measure of the amount of water in a piece of lumber.
Nominal Size- The rough-sawn size of a
piece of lumber. When purchasing planed lumber it is sold by its nominal, rough sawn,
size. For example a 2"x4" is the nominal size for a board whose actual dimension
is 1.4" x 3.25".
Ogee- A decorative molding profile with
a S shape.
Outfeed- The side of a power tool where
the board exits, (see infeed)
- Oven-dried weight-The weight of a piece
of lumber that has been dried, under high temperatures, in an oven until it is devoid of
all water. Used to calculate the moisture content of wood.
Particleboard core plywood- Plywood that
is made by gluing a thin layer of veneer to a piece of particleboard.
Phloem- The inner part of a tree's bark
that delivers water and other nutrients.
Photosynthesis- A process that plants
use to synthesize nutrients from water end minerals, using light.
Pitch Pocket- A pocket of resinous sap
confined within the grain of many conifers.
Pith- The soft core in the center of a
tree trunk.
Plain-Sawn lumber- A method of sawing
lumber where the log is cut tangential to the growth rings, also called n when referring
to, softwoods.
Porous wood- Wood with larger than
normal pores and vessels
Quarter-sawn- A method of cutting lumber
where the annual rings are relatively perpendicular to the face of the board. Quarter-sawn
lumber tends to be more dimensionally stable than other forms of lumber, such as
plane-sawn.
Radial Shrinkage- Shrinkage in a piece
of lumber that occurs across the growth rings as it begins to dry.
Ray- A ribbon like figure caused by the
strands of cells which extend across the grain in quarter-sawn lumber.
Reaction Wood- Abnormal wood tissue that
was formed in a leaning tree. Reaction wood is very unstable and prone to warping and
cupping when sawn into lumber.
Relative Humidity- The amount of
moisture in the air is measured as a percentage of the total amount of moisture the air
can hold at a particular temperature. This is known as relative humidity. The ideal
relative humidity for a home is between 35% and 45%, too much above or below these levels
problems can begin to occur.
Ripcut (ripping)- A cut made parallel to
the grain of a board.
Rotary-cut Veneer- Veneer which was cut
from a log in one long sheet. Rotary cut veneer is cut from a log like a roll of paper
towels.
Rough-sawn- Lumber that is either green
or dried that has not been dressed. (planed).
Sap- The water in a tree which is rich
in minerals and nutrients.
Sapwood- The new wood in a tree that
lies between the bark and the heartwood. Sapwood is usually lighter in color, and becomes
heartwood as the tree ages.
Seasoning- The process of removing the
moisture from green wood to improve its workability and stability.
Selects- In softwood, lumber which has
been graded strictly for its appearance. In hardwood, lumber which is one grade below
first and second.
Softwoods- Generally lumber from a
conifer such as pine or cedar. The name softwood does not refer to the density of the
wood. There are some hardwoods which are softer than some softwoods.
Sound- A term referring to a board which
has no or very few defects which will effect its strength
Specific Gravity- The ratio of the
weight of wood to an equal volume off, rater. The higher the specific gravity, the heavier
the wood.
Stain- A discoloration in wood caused by
a fungus, minerals or chemicals. A die or pigment used to discolor wood.
Sticker- A ¾" to 1" wood
strip that is inserted between stacks of green wood and spaced between 16" to
24" to allow air to flow through the stack to ensure proper drying..
Surfaced Lumber- A piece of wood that
has been planed smooth on one or more surfaces.
Surfacing- The Way a piece of lumber has
been prepared at the lumber mill.
Taper- A piece of wood that has been cut
so that it is wider on one edge than the other.
Tongue and Groove- A joinery method
where one board is cut with a protruding "groove" and matching piece is cut with
matching grove along its edge.
Twist- Warping in lumber where the ends
twist in opposite directions.
Veneer- A thin sheet of wood cut from a
log.
Veneer-core Plywood- Plywood made from
three or more pieces of veneer glued up in alternating-grain patterns.
Wane- Found usually in mill run lumber,
it is bark running along the edge length of the board.
Warp- A defect in lumber characterized
by a bending in one or more directions.
Wormholes- Holes and channels cut in
wood by insects. |
