Primary Process of Hard and Soft wood Part A Flashcards
What is the simplest method of slicing boards from a log?
the simplest method of slicing boards from a log is plain sawing.
what are three milling classifications used to describe lumber? which of these classifications is likely to be the type you you encounter most frequently as a cabinetmaker?
a) rough
b) surfaced
c) worked lumber
the milling classification type you will encounger the most frequently as a cabinetmaker is rough lumber.
what does the term hygrosopic mean?
if something is hygroscopic it has an affinity for water
what are the two ways used to reduce the moisture content of lumber?
a) air drying
b) kiln drying
list the two most important things to remember when choosing stickers for drying wood.
a) use the same species of wood
b) use wood with the same moisture content
list three types of kilns used to reduce the mosture content of wood
a) stream flood
b) vacuum
c) solar kilns
what two types of kilns are better suited to smaller volumes of wood in custom operations?
a) solar kilns
b) vacuum kilns
which type of kiln reduces the moisture of wood to suitable levesl the most quickly?
the vacuum kiln reduces the moisture content of wood to suitable levels the most quickly.
what quality of wood increases as the mosture content decreases?
the strength of wood increases as the moisture content decreases
what two types of water are present in the wood cells of a tree that is fresly felled and sawed? describe the time during hte drying process when dimensional change in the wood begins.
a) free water
b) bound water
during the drying process, dimensional change in the wood begins at the fibre saturation point or when all of the free water is gone.
what is the name of the state that wood reaches when the internal moisture content matches the ambient moisture content?
the state that wood reaches when the internal moisture content matches the ambient atmospheric moisture cntent is called equilibrium moisture content.
describe the way wood loses dimension as it dries.
as wood dries it shrinks. most woods shrink upo to 10% tangentially (across the face of a flat-sawed board) and up to 5: radially (across the thickness of a flat-sawed board
what chief quality does a grader look for when grading a hardwood board?
graders look for clear face cuttings when grading a hardwood board
three amalgamated grades for hardwood lumber?
a) FAS
b) select and better
c) No. 1 and No. 2 common
what grade of lumber is graded from the best side?
select and better lumber is graded from the best side
how can you predict whether a knot will remain tight in a board or is likely to fall out?
if a knot is not surrounded by a dar ring it will remain tight. if the dark ring is there it will likely fall out.
what are two defects caused by poorly controlled drying?
a)checks
b) splits
list five ways that lumber deviates from the true plane or square surfaces as a result of drying.
a) cupt
b) bow
c) twist
d) kink
e) diamonding
an example of a soft hardwood is __________
poplar
quareter-sawn lumber is less likely to warp than flat-swan lumber.
true or false
true
the abbreviation S-DRY on a grade stamp means _______
S-DRY means surfaced dry
bark that remains on the edges of lumber is known as _________
wane
if lumber has saw cut marks still visible on the otherwiese dressed surface, this defect is called ______
skip
hardwood that is called eight-quarter stock is ______ inches thick.
two inches
what characteristic is present in a healthy hardwood bush?
a diversity of plant and animal species is present in a healthy hardwood bush.
what two of harvesting practises are employed in removing wood from the bush
a) clear-cutting
b) selective logging
what type of harvesting is most common in coniferous forests? list the reasons that this type of harvesting is employed in softwood forests.
clear-cutting is most common in coniferous forests. it is employed in softwood forests because it mimics the destructiveness of nature (fire) and reduces the overall impact in the bush by limiting the time that peoople and heavy machinery are in the forest
what type of harvesting is employed in some hardwood forests? list the reasons that this type of harvesting is employed in hardwood forests.
selective logging is employed in some hardwood forests becasue hardwood regenerates itself and individual trees need to be culled and surviving trees thinned and pruned. also the bush will continue to produce the same amount of wood each year forever and will remain a healthy diverse habitat for plant and animal species
what two types of saws are employed in milling logs for lumber?
a) circular saws
b) band saws
what are two types of defects that affect the grade of lumber?
a) natural
b) manufactured defects
what is the name of the defect usually found in softwood in which some sap is trapped inside the wood?
pitch pockets
what is the name given to a separation of growth rings?
ring shake
which defect may be caused by an infestation of ambrosia beetles?
infestation of ambrosia beetles can cause pinholes
list three shapes of knots
a) roujd
b) oval
c) spike
