WOODWORKING Technology Education Dept. Bellwood-Antis Middle School Mr. Mackereth
ADVANTAGES OF USING LUMBER & WOOD PRODUCTS • WHY MAKE THINGS OUT OF WOOD? • Wood is both STRONG & LIGHTWEIGHT. • Wood is BEAUTIFUL & ATTRACTIVE. • Wood is from a RENWEABLE RESOURCE. • Wood can easily be CUT, SHAPED, SANDED, and SEALED. • Wood COSTS LESS than other materials.
OLDER HARVESTING METHODS • For hundreds of years, companies harvested timber in the forest usingCLEARCUTTING. • This method CUT DOWN EVERY TREE in the forest, leaving the land bare and ruined. • Soil eroded during rainstorms forming gullies. • Wildlife (land animals) had no place to live. • Soil and mudslides polluted the streams. • Aquatic life (fish and reptiles) were killed. • In general, CLEARCUTTING RUINED THE FOREST!
LOGGING METHODS INTODAY’S WORLD • Today’s lumber & logging companies practice REFORESTATION (regrow, replant) in the woods. • A. SELECTIVE CUTTING- We cutONLYa certain kind of tree, or trees of a certain diameter • B. PLANTING TREE SEEDLINGS- We replant tree seedlings after we are done logging for the future. • C. SOIL & WATER CONSERVATION- We make sure that no soil enters the streams and rivers, or that none of the water resources are polluted.
LOGGING METHODS INTODAY’S WORLD (cont.) • Today’s lumber & logging companies practice REFORESTATION(regrow, replant) in the woods. • D. LUMBER BY PRODUCTS- We make solid lumber products out of the scraps left over from the mill. This includes OSB, mulch bark, or composites. • E. RECYCLING PAPER- The more paper we recycle, the less trees need to be cut down for paper! • EVERYONE PITCHING IN & DOING THEIR PART HELPS OUR FOREST RESOURCES!
PHYSICAL CHARACTERISTICS OF TREES AND LUMBER PRODUCTS • Living trees are made up of CELLS, just like the human body. When the tree is harvested for lumber, cut at the mill, and dried, these cells….. • are called WOOD FIBERS. A collection of the • wood fibers is called theGRAINof the wood. • Cutting with the grain is calledRIPPING. • Cutting across the grain is called CROSS CUTTING.
PARTS OF A TREE • 1- OUTER BARK • 2- INNER BARK • 3- CAMBIUM CELLS • 4- SAPWOOD • 5- HEARTWOOD • 6- PITH (young tree)
FUNCTION(S) OF TREE PARTS • OUTER BARK-Protects the inside of the tree • INNER BARK- Transports food (sugar, sap) up the tree in winter/early spring, down during rest of time • CAMBIUM CELLS- Growth cells that multiply and divide to create new layers (annual rings) in the tree • SAPWOOD-Transports water & minerals up the tree • HEARTWOOD- Center most part of the tree, gives the tree strength and color.
TYPES OF TREES • HARDWOOD SPECIES- trees that have flat, blade- like leaves, and loose their leaves every year. • Examples of HARDWOODS: OAK MAPLE • POPLAR BASSWOOD WALNUT CHERRY • SOFTWOOD SPECIES- Trees with needle-like leaves and cones, keep their needles for more than 3 years • Examples of SOFTWOODS:PINE SPRUCE • HEMLOCK RED CEDAR DOUGLAS FIR
ANY QUESTIONS? • This concludes part one of the wood notes. • COMPLETE THE REVIEW WORKSHEET FOR THESE PAGES OF NOTES (Due on___________) • STUDY FOR THE QUIZ! • AS SOON AS YOU TAKE AND PASS YOUR QUIZ, YOU WILL BE WORKING IN SHOP!
SAWING LUMBER IN A MILL • At the mill, lumber can be cut in two ways: • PLAIN SAWING- The WHOLE log gets placed on the carriage and “sliced” into boards. • Plain sawing is used for common lumber, but it bows, warps, and twists easily (out of shape.) • QUARTER SAWING- The log gets cut into quarters, and the ¼ log is “sliced” into boards. • Quarter Sawing is used for EXPENSIVE lumber. It does not usually bow, takes more work, time, $.
SAWING LUMBER IN A MILL (cont.) • The pieces that are cut off of the logs are called • SLABS, & some still have the BARK left on the edges • Those with bark edges are sent through an EDGERto remove bark make all the edges straight & true. • The edged boards are sent through TRIMMER or CROSSCUT saws to SQUARE the ENDS. • The trimmed boards are usually cut into lengths of 8, 10, 12, or 16 feet making them easier to ship. • The fresh cut boards are now called GREEN LUMBER
PROCESSING BOARDS IN THE MILL • After sawing, the lumber enters the GREEN CHAIN. • The lumber is SORTEDinto different GRADESbased upon the APPEARANCEof the board & the presence of DEFECTSthat effect the GRADE of the board. • Next ALL LUMBER is AIR DRIED outside to remove SOME, but not ALL, of the moisture content. • HIGHER GRADE LUMBER is then KILN DRIED in a CLOSED, HEATED building (removing more moisture) • Boards are FINISHED drying at about 6% MOISTURE.
PROCESSING BOARDS (cont) • HARWOOD LUMBER GRADES are: • SELECT FIRST SECOND • HARWOOD LUMBER GRADES are: • SELECT FIRST COMMON SECOND COMMON • Defects that can be found in lumber include: • BOWING (warping) KNOTS PITCH POCKETS • METAL CONTENT CRACKS WANE EDGES
COMMON LUMBER PRODUCTS • BOARDS-used for assorted projects & framing • STUDS- used to frame homes, buildings, and rafters • PLYWOOD-laminated layers/plies glued together in 4 x 8 sheets. Used for walls, roofs, flooring, cabinets • VENEER BOARDS and VENEER PLYWOOD- used to make interior doors, cabinets, and furniture • VENEERis a term describing the process of taking a thin layer/ply of SELECT lumber and glue it on top of lower grade, but solid boards (our doors & cabinets)
COMMON LUMBER BY-PRODUCTS • FLAKEBOARD- “flakes” of wood are glued & pressed together into 4 x 8 sheets. Flakeboard and OSB are used the same way that plywood is used in homes. • Oriented Strand Board (OSB)- similar to flakeboard, but has a moisture barrier on one, “shiny” side. • MINERAL CORE BOARD- scrap materials & mineral composite glued/pressed between 2 plies of veneer • Remember, these are SCRAP products from the mill
WORKING WITH BOARDS IN SHOP • Lumber used in shop is KILN DRIED FAS (1st & 2nd) • The FIRST STEP is to PLANE them. We use a SINGLE SURFACE PLANER to shave 1/16” at a time until we havePLANEDthe board to the EXACT THICKNESS. • Next, we take the planed board over to the JOINTERto joint 1 EDGESQUAREwith the board’s surface. • This provides a smooth, jointed edge to slide easily along the fence of the table saw (the next step.)
CUTTING PROJECT PIECES • The 3RD & 4TH steps are done on a TABLE SAW. • We set the fence of this saw to the EXACT WIDTH we want the board to be when we are finished. • If the board is wide enough for two or more cuts, or if multiple boards are cut, the saw is set only once. • We push the board CAREFULLY & SLOWLY through the saw making a RIPPING cut (with the grain.)
CUTTING PROJECT PIECES • The 5th & 6th STEPS can be done on either a RADIAL ARM SAW (large pieces) or a MITER SAW (small.) • We CAREFULLY TRIM ONE END SQUARE with a CROSSCUT. This makes the end EVEN & SQUARE. • Then weMEASURE the board to its EXACT LENGTH. • We then place the board back on the saw, and we CROSSCUTthe board to its EXACT LENGTH. • NOW WE HAVE OUR PROJECT PIECE!
ANY QUESTIONS? • This concludes part one of the wood notes • COMPLETE THE REVIEW WORKSHEET FOR THESE PAGES OF NOTES (Due on___________) • STUDY FOR THE QUIZ! • AS SOON AS YOU TAKE AND PASS YOUR QUIZ, YOU WILL BE WORKING IN SHOP!