Introduction to Wood

1. Introduction to Wood Before we can begin any work in the shop, we have to understand a little bit about trees and how trees are processed into a usable resource. So let's begin with the tree itself.

2. Choosing Lumber • Important step • Expensive • Know Options • Natural Characteristics • Various lumber grades

3. Anatomy of a tree • Pith • Heartwood • Sapwood • Cambium • Phloem • Bark • 2 growth spurts • Earlywood • Latewood

4. Hardwoods vs. Softwoods • Softwoods • Coniferous • Grow rapidly • Wide bands of earlywood • Earlywood – large less dense cell structure • Hardwoods • Deciduous • Grow slowly • Narrow bands of earlywood • Earlywood dense cell structure

5. Plain-sawn Maximizes lumber Prone to distortion Through-and-through Simplest method Lumber is unstable Quartersawn Produces less lumber Close, tight, straight grain More expensive Typical lumber cuts

6. Lumber Drying Methods • ‘Green’ Lumber • Air Drying • Kiln Drying

7. Moisture & Wood Movement • EMC – Equilibrium moisture content • Wood expands and contracts • Tangential movement • Radial movement • Longitudinal movement • Let lumber acclimate • It is critical to consider how forces of expansion and contraction will affect your project; however, they cannot be entirely eliminated.

8. Common Lumber Distortions • 4 types of distortion • Bow • Crook • Cup • Twist • Spotting distortions

9. Pitch Pockets Spalling Loose Knots Checks Splits Shakes Honeycomb Wormholes Wane Common Lumber Defects

10. Softwood Lumber Sizes • Softwood Lumber Dimensions – 1x Nominal • Softwood Lumber Dimensions – 2x Nominal

11. Softwood Lumber Grades • Graded by • Strength • Appearance • Moisture Content • 3 Common grades • Select • B Select and BTR • C Select • D Select • Finish • Superior Finish • Prime Finish • Common • No.1 Common • No.2 Common

12. Hardwood Lumber Sizes • Nominal from Home centers • Usually only ¾” thick • Usually S4S (Surfaced 4 Sides) • More expensive • Traditional lumberyard • Carry S4S, S2S, roughsawn • More thicknesses • Quartering system (pre-planed thickness) • ¾ (3/4”), 4/4 (1”), 5/4 (1 ¼”), 6/4 (1 ½”), 8/4 (2”), 10/4 (2 ½”), & 12/4 (3”)

13. Hardwood Lumber Grades • 3 Grades • FAS (Firsts & Seconds) 83 1/3% clear • Select 83 1/3% clear • Common • No. 1 Common 66 2/3% clear • No. 2A & 2B Common 50% clear • No. 3A Common 33 1/3% clear • No. 3B Common 25% clear

14. Calculating Board Feet • 1 board foot is 1/12 of a cubic foot • T x W x L (all in “) divided by 144 • Build some waste into estimate • Special Calculators • Computer programs • Ipod touch and Iphone app

15. Buying Lumber • Chain home centers • Contractor yards • Specialty yards • Reclaimed lumber • Mail-order lumber

16. Buying Basics • Develop a realistic shopping list • Consider less-expensive wood for hidden parts • Factor in about 30% waste • Comparison shop • Plan for transportation

17. Sheet Goods • Cover large area w/no seams • Dimensionally stable • Relatively inexpensive • Plywood • Particleboard • Medium-density Fiberboard (MDF) • Melamine board

18. Common Hardwoods • Red Oak • White Oak • Hard Maple • Cherry • Walnut

19. Common Hardwoods • Birch • Hickory • Aspen • White Ash • Poplar

20. Common Softwoods • White Pine • Western Red Cedar • Aromatic Cedar • Redwood • Cypress

21. Padauk Zebrawood Wenge Honduras Mahogany Purpleheart Teak Rosewood Sampling of Exotics