3. LEARN THE DIFFERENT WOOD MILLING CUTS
Looking at the board’s end grain will tell you how a board was sawn from the log, and how stable it will be. In a minute I’ll jump into each of these cuts in a little more detail, but this graphic illustrates how different cuts come from the log:
But mills rarely cut up a board like the graphic above. “Through and through” is the most common method that lumber mills employ when milling lumber. It’s simply like slicing horizontal layers along the length of the log:
You’ve probably seen someone do the same thing with a chainsaw mill at home. Bill Anderson shared some valuable insights with me regarding lumber cut with the “through and through” method: “Depending on where in the log the boards come from, they will be either flat, rift or quartersawn, or show a transition between these cuts across the width of the board.”
Take special notice, in the above graphic, how stable wood can extract from a wider board.
Lumber sellers don’t always label the cut of their boards, so don’t hesitate to carry a sharp block plane to the lumber yard to uncover the end grain:
You’ll often need to remove the mill marks and the colored wood end grain sealer to see the end grain.
You should definitely dig through the boards and use your knowledge from this article to select the best you can find. You can also find good “vertical grain” as part of a larger flat sawn board, and just cut it off both edges (leaving the center for fire wood):
Here is what the different main lumber cut types look like after the’re cut off of a flat sawn board:
Let’s discuss each of them in a tiny bit more detail:
A. FLAT SAWN / PLAIN SAWN (LEAST STABLE)
Most consumer-grade boards are flat sawn, and often display a “cathedral” pattern on the board face:
Lumber companies want to maximize their profits by getting as many boards out of a log as possible. You can definitely use flat sawn boards in your projects, but just realize that the wood will move over time, and may cup or twist and separate your wood joints. Although some joints can be arranged to better accommodate the movement (see part 1/15 of my dovetail tutorial…skip to 1:41) it’s better to start out with wood that isn’t going to move as much. In section 4 below you’ll see some problems that are common to flat sawn boards (like twist, cupping, bowing, etc.).
If the flat sawn boards have already moved out of square, then you’ll have to spend some considerable time flattening & straightening the board right before you use it. So it’s best to stick with a more stable cut of lumber, like quartersawn lumber. Or at least keep your flat sawn boards stacked (until the last possible moment) with “stickers” between them and weights on top to prevent movement, then secure them with good joinery or fasteners (e.g. nails) when building furniture.
B. QUARTERSAWN LUMBER (VERY STABLE)
Quartersawn wood is very stable, and less susceptible to movement. The 60-90 degree vertical grain qualifies a board as “quartersawn” within the lumber industry. See how the end grain is running nearly up-and-down? That is called “vertical grain”. Quartersawing also produces fairly straight face grain and usually very beautiful ray flecks (for example, see the flecks on the beech wood above).
But since quartersawing requires more effort and wastes more wood, it is naturally more expensive. But you don’t have to run out to your local mill and ask for the quartersawn boards. As mentioned in the last section, quartersawn wood can be cut off the edges wide flatsawn boards. Yes, even from construction lumber!
To produce 12″ wide construction lumber (2×12 pine boards), lumber companies have to use the center of the tree. So naturally quartersawn & riftsawn lumber will be on the edges, and just needs to be cut off. This is how Roy Underhill gets nice quartersawn yellow pine at low prices from big box stores like Lowes & Home Depot. He taught me this when I was helping him rip a wide piece of construction lumber for his school teacher’s desk tv program (watch the episode).
Notice how the above 2×12 construction-grade flat sawn board actually has some very stable quartersawn wood on both sides of the wide board? Here’s what it looks like after I cut it off with a rip saw and use handplanes to square it up:
C. RIFTSAWN LUMBER (MORE STABLE)
The riftsawn section of a board is similar to quartersawn cuts, but its endgrain is between 30-60 degrees to the face. Riftsawn boards have a characteristically straight face grain pattern. These boards are also pretty stable and can be utilized if your furniture project calls for extremely straight face grain, like modern or Japanese-style projects.
D. RIVEN LUMBER (MOST STABLE)
The most stable boards are “riven” or “rived” directly from a log by you, exploiting the weakness of the grain (like splitting firewood). Riven boards are a subset of quartersawn because they are also split along the radial plane of the log, producing grain lines that are square to the board face and straight down the board.
These boards are not only the most stable, but they can also be some of the most beautiful with maximum “fleck”:
So why do you not hear about this type of lumber very often? Because wood mills and lumber yards don’t have it. Their boards are cut with large powerful saws. Riven boards require muscle power and hand tools like a large crosscut saw (or chain saw), wedges, mallets, a froe, an adze, a hewing hatchet & handplanes.
I’ll share a riving video tutorial at a later date. But in the meantime, Peter Follansbee shows how to rive your own red oak from logs, as part of his helpful DVD video: “17th Century Joined Chest.”
Here is a very helpful animation (from a professional miller) that clarifies the quartersawn & riftsawn process: