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Chapter 2
IN THIS CHAPTER
Understanding the characteristics of wood
Looking into the different kinds of solid wood
Discovering everything you want to know about veneers
Understanding plywoods and manufactured boards
Figuring out where to find wood
Knowing the basics on buying
This chapter is all about wood. Hardwood, softwood, plywood, veneer wood. Plain-sawn wood, rift-cut wood, quarter-sawn wood. Solid wood, manufactured wood. Wood, wood, wood. Did I mention this chapter is about wood?
The key thing to know is that wood isn't a static thing. It's a natural product that's constantly moving. As a woodworker, your job is to understand how wood moves and how to use that movement to your best advantage (or at least how to keep it from ruining your masterpiece). This chapter helps you understand how boards are made out of trees and discover that the way the log is cut determines its ultimate strength and stability (and its beauty). Additionally, you explore the characteristics of a variety of species of hardwoods and softwoods.
But that's not all. In this chapter, I talk about one of modern times' greatest gifts to the woodworker: manufactured boards (also called sheet goods) and veneers. Yep, wood technology can help you keep your sanity while also speeding up the process of making furniture. Oh, and it can also save you some bucks in the process. What's not to like about that?
If you've ever been to a lumberyard and seen the huge stacks of wood in varying lengths, thicknesses, grain patterns, and colors, you understand what a daunting task it is just to find a couple of boards that match. Luckily, you can find some great wood with just a few pieces of information and a little patience (and a decent lumber yard).
Every board at the lumberyard has a grade assigned to it. A grade is a code that tells you about the board you're looking at. Grades refer to the quality of the grain (the way growth rings appear in the board) and the number of defects (knots, holes, cracks, and so on) in the board.
Sure, you can look a board over carefully and grade it yourself (which you should do anyway), but an official grade can speed up the process by weeding out the boards that are simply too full of defects. The National Hardwood Lumber Association (NHLA) lists seven grades of wood:
Because the rules for determining the grade of a board are very complicated and species-dependent, I can't go into too much detail about them in this book. (However, if you have an inquiring mind and want to know the details, see the NHLA website at https://www.nhla.com/.)
https://www.nhla.com/
After the wood is cut, it needs to dry before it can be used, and drying the wood causes shrink age in the board. So the board must be allowed to dry evenly, or it twists, bows, or warps. If you buy wood from a lumberyard, it's already been dried, but you want to acclimate it to your shop before you work with it. This way, the wood will make any changes it needs to make with the different humidity levels in your shop, and you don't get any nasty surprises like a table leg that twists after you've glued your project together.
The best way to acclimate your wood to the humidity of your shop is to create horizontal racks and lay the boards flat on them. (I talk more about this process in Chapter 8.) Leave them for a few days, and they're ready to go.
For woodworking, you want wood with few defects and the best-possible wood grain pattern. For the most part, you want the top two grades of wood: Firsts and Seconds. These two are often grouped and referred to as FAS (Firsts and Seconds). Most decent lumberyards are well stocked with FAS boards and some Selects. The "common" classes aren't used in furniture-making because they contain far too many defects.
Resist the temptation to buy "common" grades of wood for furniture even when the price seems great. Cutting all the defects out takes a ton of time. Besides, by the time you make the lesser quality wood usable, you don't have much wood left over. When you buy a cheap board and cut it up to find usable parts, you spend more money than it costs you to buy the better quality stuff to begin with.
To get a flat board, you have to cut a round log in a particular way so you can get the grain to run how you want it to. The orientation of the blade in relation to the log and its growth rings determines the type of cut the board ends up with. You can cut a log in three main ways:
Through and through: This type of milling involves progressively cutting the log from one side to the other (see Figure 2-1).
Through-and-through milling is the simplest and most efficient way to cut a log. Milling through and through results in plain-sawn, rift-sawn, and quarter-sawn boards because the orientation of the growth rings changes as the boards are sliced off the log. (See the "Choosing the right wood cut for you" section later in this chapter for more information.)
FIGURE 2-1: Cutting a log through and through results in a variety of boards.
Quarter-sawn: Quarter-sawn milling is the least efficient way to cut a log, but it produces some of the best boards. You can mill a quarter-sawn board in two ways: the preferred way (Figure 2-3 left) and the practical way (Figure 2-3 right). Unless you have a mill of your own, you will need to have it milled to your specifications, you'll have to live with the practical method of quarter-sawing wood. Don't worry - this is still a great way to mill a log. Also, because it's more efficient than the "preferred" method, it doesn't cost you an arm and a leg to buy (maybe just the arm).
Quarter-sawn boards (see next section) are more stable and attractive (to me, anyway) than the other types of boards, but they are much more expensive. They're also unavailable for some types of wood.
FIGURE 2-2: Plain-sawn milling results in plain-sawn and rift-sawn boards.
FIGURE 2-3: Quarter-sawing a log can be performed in two ways: the preferred method (left) and the practical method (right).
When you get to the lumberyard (or when you order over the phone), you can choose from three cuts of wood: plain-sawn, rift-sawn, and quarter-sawn. The difference between each type of cut is in how the growth rings relate to the board's face (wide side).
The relationship between the growth rings and the board's face determines its overall stability (the amount of movement that occurs with changes in humidity). For example, plain-sawn boards have growth rings at a low angle to their faces, so they will have as much as ¼-inch movement across a 12-inch-wide board as the climate gets drier or wetter. Rift-sawn boards move less because the growth rings are at a steeper angle to the face (maybe as much as ? inch for a 12-inch board). Quarter-sawn boards have the least movement with changes in humidity because the growth rings are at an almost 90-degree angle (almost no discernible change in width with changes in humidity). This makes the quarter-sawn board the most stable type of cut available. Regardless of the cut type, humidity changes have very little effect on the board's length and thickness.
Plain-sawn boards are the most common boards at your lumberyard (check out Figure 2-4 for a look at a plain-sawn board). When you choose or order wood without designating the type of cut, you get plain-sawn boards. Plain-sawn boards have growth rings that run less than 30 degrees against the face of the board.
FIGURE 2-4: A plain-sawn board has a circular grain pattern and growth rings less than 30 degrees from the face.
Without the tree, woodworkers wouldn't have anything to build from. It's a shame, however, that so little of the tree can be used for furniture. (At least the rest can be used for other stuff, like the paper on which this book is printed.) The trunk of the tree is where woodworkers get wood for projects. On the other hand, the branches aren't good for furniture because they contain too many defects and aren't as strong.
A tree consists of several layers. From innermost to outermost, they are
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