1. Wood Working

2. Wood Working
After completion of this unit, the student should be able to:
A. Identify types and grades of lumber used in agricultural structures.
B. Distinguish between nominal and actual lumber measurements.
C. Calculate linear and board feet.

3. Methods of Cutting Lumber from Logs
A. Plain sawing
… cut at a tangent to the growth rings
B. Quarter sawing
… cut the log in quarter, cut boards perpendicular to the growth rings

4. Methods of Cutting Lumber from Logs

5. Methods of Cutting Lumber from Logs

6. Methods of Cutting Lumber from Logs
Plain sawing, cutting the log on a tangent to the growth rings, is faster with less waste resulting in lower cost lumber. It produces a flat or slash-grained lumber that is used for most buildings.

7. Methods of Cutting Lumber from Logs
Quarter sawing lumber, produced by cutting the log perpendicular to the growth rings, results in lumber less likely to warp, shrink, and swell.
Since quarter-sawed edge or vertical grained boards have a prettier grain, they are often used to make furniture.

8. Kinds of Wood
Softwoods – comes from needle-leaf, evergreen trees called conifers.
-pine, cedar, fir, redwood, and cypress.

9. Kinds of Wood
Hardwoods – comes form broad-leaf trees that lose their leaves each fall season, called deciduous trees.
-oak, ash, birch, cherry, sycamore, walnut, hickory, and maple.

10. Kinds of Lumber
1. Wood cut into uniform thickness, width, and length is called lumber.
a. Boards- flooring, sheathing, paneling, and trim.
b. Dimension- sills, plates, studs, rafters, and other framing members.
c. Timbers- posts, beams, and heavy stringers.

11. Wood Boards
Wood panels (usually 4' x 8') are made through various methods.
Plywood consists of thin
layers of wood glued
together with the wood
grain turned at right
angles in each
successive layer.

12. Wood Panels
Oriented Strand Board (OSB) consists of high quality flakes of wood (about 1 1/2 inch square) bonded together under heat and pressure with the waterproof adhesive, phenolic resin.

13. Wood Panels
Composite board consists of a core of wood fibers bonded on either side with veneer.

14. Wood Panels
Hardboard consists of refined wood fibers pressed together to form a hard, dense material ( lb. per cu. ft.).

15. Wood Panels
Particle board consists of wood flakes, chips, and shavings bonded together with resins or adhesives to form a less dense material.

16. Dimensional Lumber

17. Lumber Grades 1) Grades A and B are suitable for natural finishes.
2) Grades C and D are suitable for paint finishes.

18. Calculating Board Feet
Pieces Lumber
” X 4” X 12’
” X 4” X 10’
” X 4” X 8’

19. Calculating Linear Feet
Pieces Lumber
” X 4” X 10’
” X 4” X 16’
” X 4” X 8’