WOOD Flashcards
is that fibrous substance which composes the trunk and branches og the tree that lies between the pith
Wood
is the term applies to wood when it is sawed or split into timbers, planks, and boards
Lumber
unplaned or undressed lumber
Rough Lumber
has at least one smooth surface
Surface or Dressed Lumber
is milled to the molder to a specified edge
worked lumber
intended to be cut up ihto further manufacture
Shop Lumber
Less than 5 inches in thickness and including strips, boards, and framing members(studs, joints, and rafters). The grading is based on length.
Yard Lumber
2 inches or 5 inhes thick (yard lumber)
Dimensioned Lumber
Same to yard lumber but is over 5 inches thickness and width. The grading is based on strength.
Structural Lumber
a piece of lumber cut tangent to the annual rings, running the full length of the log and containing one flat surface
Slab
a piece of lumber more than 5 inches in its smaller dimension
Timber
a wide piece of lumber ranging from 1 1/2 to 5 inches in thickness
Plank
a piece of lumber less than 1 1/2 inches thick and 4 inches og more in width
Board
a term applied to a piece of veneer, plywood, or other manufactured board.
Sheet
a thick piece of lumber or log which is to be cut into veneer . It may also refer to the pile of veneer cut from one log.
Flitch
Classification of Wood (6)
Mode of Growth
Density
Leaves
Shade or Color
Grain
Nature of the surface when sawed
are those outward growin trees that are most preferred for lumbering
Exogenous
are those inside growing trees that are not preferred for lumbering because they produce soft center core
Endogenous
it is either soft or hard
Density
two types of leaves
Needle Shape
Broad Shape
Shade or Color (5)
White
Yellow
Red
Brown
Black etc.
Types of Grain
Staight
Cross
Fine
Coarse
Nature of the surface when sawed
Plained
Grained
Figured
Marked
a process or operation from cutting trees, hauling, and delivery of wood to the sawmill for sawing
logging
is applied to the operations performed in preparing the wood for commercial purposes
lumbering
process of cutting logs into commercial sizes of lumber
sawing
methods and manner of log sawing are
plain and bastard sawing
quarter or rift sawing
4 ways of quarter or rift sawing
radial
tangential
quarter tangential
combined radial and tangential
irregularities found in wood
defects
classification of defects in wood
natural defects
seasoning defects
due to deterioration
are radial cracks originating at the heart of the logs commonly found in old trees
heart shakes
is the separation of the rings in a piece of wood that occurs as it dries
wind shakes or cup shakes
are composed of several heart shakes which radiates from the center of the log in star-like manner
star shakes
occurs at the stsrting point of a limb oŕ branch of the wood
knots
4 types of natural defects
heart shakes
wind shakes or cup shakes
star shakes
knots
4 classification of knots
pin knota
small knots
medium knots
large knots
:caused by faulty techniques of seasoning
:different types of permanent distortion of timber and ruptures of tissues separately or together
seasoning defects
types of seasoning defects
warping
check
split
wane
crook
Types of warping
cupping
bow
twist
the distortion in convented timber caused departure from its original plane usually during seasoning period
warping
:when the board bends edge to edge cross the face pf the boards will look like the letter U
:common in boards that are cut close to the pith
cupping
a board that bends along the grain lines
bow
a board that bends in any variety of direction and cannot maintain a straight line
twist
used to describe a crack that runs through a board, usually running lengthwise
check
crack extends from face to face of the wood
split
the presence of bark or the absence of wood on thr corners of a board
wane
board that is bent end to end in the direction of the tall ends of a board as it continues down the length of the board
crook
2 types of defects due to deterioration
dry rot
wet rot
caused by a fungi in a seasoned lumber due to the presence of moisture
dry rot
takes place sometime in the growth of the tree caused by water saturation
wet rot
is the controllesd process of reducing the moisture content of the timber or lumber so that it is suitable for the environment and intended use
seasoning
2 methods of seasoning lumbers
natural or air seasoning
artificial seasoning
:is the method used with the timbers or lumbers stacked in the open air
:considered as one of the best method seasoning timbers and lumbers, although the period involved is relatively longer
natural or air seasoning
:is a process wherein the lumber is stacked in a drying kiln and then exposed to steam and hot air
:wood from this process undergoes quizck drying and is classified as quite inferior in quality as compared to those lumber seasoned by air seasoning method
artificial seasoning
3 artificial seasoning
forced air drying
kiln air drying
radio frequency dielectric drying
is the process of acceleratibg seasoning or achieving faster and more uniform pre-drying prior to kiln drying
forced air drying
this process begins with forced air drying or fan drying. it differs from the air dryin in the sense that the process is speededby control of the temperature and humidity, as well as the circulation of air, in a special built of room and chamber
kiln air drying
when the electronic disturbance occurs, the innermost molecules begin moving
radio frequency dielectric drying
4 common causes of decay in wood are
alternate moisture and dryness
fungi and molds
insects and worms
heat and confined air
2 process of preserving wood are as follows
external
internal
the wood is coated with preservative(as paint) which penetrayes the fiber
external preserving
a chemical is integrated as pressure to permeate the wood thoroughly
internal preserving
its purpose is to compel additive synthetics profound into the cell construction of the wood
pressure-treated wood
