19 - Clamp Storage System, страница 30
The key to identifying lumber grain is "reading" the end of the board.
■ When buying hardwood, I have a hard time telling the difference between flatsawn, riftsawn, and quartersawn lumber. Is there a simple ■way to do this?
Jerome Lewis Manhattan, Kansas
The simplest way to tell the difference is to look at the end of the board. What you're looking for is the angle of the growth rings. This angle is determined by how the lumber was cut, see Drawing.
flatsawn. On flatsawn lumber, the rings will be 30° (or less) to the face of the board, see below. In many cases, especially with boards coming from large diameter logs, the rings will be parallel to the face.
Flatsawn lumber is the most common type of lumber you'll come across because a log yields the most lumber when cut this way. Because of this, it's the least expensive cut available.
But flatsawn lumber tends to move a lot with changes in humidity — it often cups or warps. And the grain swirls in many directions over the face of the board.
END GRAIN IS 30' OR LESS TO FACE
Flatsawn. On flatsawn lumber, the growth rings are 30° (or less) to the face of the board. The grain is the wildest of the three cuts.
When this wild-grained wood is stained, the softer, more porous early wood will soak up more stain and look darker than the harder, less porous late wood.
riftsawn. When I'm sorting for more attractive boards, I'm looking for riftsawn lumber. In this case, the growth rings are
greater than 30°, but less than 60° to the face of the board, see below.
Riftsawn lumber generally has straighter, clearer grain than flatsawn lumber. Usually, riftsawn lumber is mixed right in the same stack as flatsawn lumber.
In fact, many boards in a flatsawn stack will have both riftsawn and flatsawn grain. When a
FACE GRAIN IS RELATIVELY STRAIGHT
END GRAIN IS BETWEEN 30° AND 60° TO FACE
Riftsawn. With riftsawn lumber, the growth rings are greater than 30°, but less than 60°. The grain runs fairly straight across the face.
single board has both types of grain, what you'll actually see is wild grain running right alongside nearly straight, clear grain.
Another reason I look for riftsawn wood is for its stability — it's less likely to warp or cup than flatsawn lumber.
quartersawn. The straight-est grain comes from logs that are quartersawn. Here, the growth rings will be 60° to 90° to the face of the board, see below.
In addition to really straight grain, some hardwoods (such as red and white oak, cherry, and hard maple) exhibit highly figured face grain (ray flecks) when quartersawn. And when finished, these woods can be quite striking.
Also, when the humidity does change, quartersawn lumber is the most stable of the three different cuts of lumber.
The downside to quartersawn lumber is it requires larger logs to produce reasonably wide boards. And since there's more waste, it's the most expensive.
FACE GRAIN IS STRAIGHT AND CAN BE HIGHLY FIGURED
END GRAIN IS BETWEEN 60° AND 90" TO FACE
Quartersawn. The growth rings on a quartersawn board are 60° to 90°. On certain hardwoods, the face grain is highly figured.