february 04, 2014 · february 04, 2014 lumber defects vocab blue stain: discoloration caused by a...
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selectingmaterials.notebook
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February 04, 2014
Lumber Defects Vocab
Knots: caused by an embedded limb or branch of the tree. It reduces the strength but in some cases may add to the appearance
Splits and Checks: a separation of the wood along the grain and across the annual growth rings
Shakes: separations along the grain and between the annual growth rings
Pitch Pockets: internal cavities that contain or have contained, pitch in solid or liquid form
Honeycombing: Separation of the wood fibers in the interior of the wood, usually along the wood rays.
Wane: the presence of bark or absence of wood along the edge of a board
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February 04, 2014
Lumber Defects Vocab
Blue Stain: discoloration caused by a moldlike fungus. It has little or no effect on strength.
Decay: disintegration of wood fibers due to fungi. Wood is soft, spongy, and crumbles easily.
Holes: caused by handling equipment or boring insects and worms.
Warp: any variations from a true plain surface and may include any one of the following: cup, bow, crook, and twist
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February 04, 2014
Selecting and Identifying Materials
Mr. BiddickWood Technology
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February 04, 2014
Lumber Defects
A defect is an irregularity occuring in or on wood that reduces its strength, durability or usefulness
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February 04, 2014
Major Warpage
bow : a warp along the length of the face of the wood
crook: a warp along the length of the edge of the wood
kink: a localized crook, often due to a knot
cup: a warp across the width of the face, in which the edges are higher or lower than the center of the wood
twist: a distortion in which the two ends do not lie on the same plane
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February 04, 2014
Seasoning Lumber
The quality of lumber is also indicated by the method of drying
Green Lumber=freshly cut logGreen lumber=excessive amount of moisture(sap)most moisture must be removed before use
Air Dried=exposed to air over long period of timeAir Dried=moisture reduced to 1218%
Kiln Dried=huge ovens Kiln Dried=710% moisture content
Measure moisture=moisture meter
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February 04, 2014
Board Measure
Board measure indicates that a board foot is the unit for measuring lumber.
Board foot=one inch thick and 12 inches square(12x12)
The number of board feet in a piece is obtained by:Thickness(nominal)xWidth(nominal)x Length/144
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February 04, 2014
Figuring Board Footage
The number of board feet in a piece is obtained by:Thickness(nominal)xWidth(nominal)x Length/144
1 inches thick, 5 inches wide, 6 feet long
(1x5x72)/144
Why 72?6ftx 12 inch=
= 30 board feet
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February 04, 2014
Panel Materials
Wood panels are manufactured in several forms:
1.Plywood where thin piles are laminated to form various thicknesses2. Composite plywood where veneer faces are bonded to different wood cores3. Nonveneered panels including waferboard, particle board, and oriented strand board
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February 04, 2014
Plywood
Constructed by gluing together a number of layers(plies) of wood with the grain direction turned at right angles in each successive layer
ClassificationSoftwoodDouglas Fir, Ponderosa PineHardwood
Types of PlyExterior(waterproof) and Interior(furniture)
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February 04, 2014
Composite Board
Panels made up of a core of reconstituted wood with a thin veneer on either side are called composite board
Resins (glue) glues it all together
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February 04, 2014
Waferboard
Flakes bonded together under heat
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February 04, 2014
Oriented Strand Board
Layers of compressed strandlike particles arranged at right angles to each other
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February 04, 2014
Handling and Storing
Lumber that is used for cabinetmaking or finished should be handled carefully
Protected from=excessive moisture, dust/dirt, dents
Whether rough or surfaced=carefully stacked
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February 04, 2014
BELLWORK
Pull out worksheets and begin working quietly
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February 04, 2014