Hasta La Ideas

This is the third post of an ongoing series about wood. Understanding its nature, the way it moves and changes, and the implications for designers. Check back every Wednesday for the next installment.

The first two posts are here:
» How Logs Are Turned Into Boards, Part 1: Plainsawn
» How Logs Are Turned Into Boards, Part 2: Quartersawn

What is Riftsawn?

As we mentioned in the previous post, there is confusion about what constitutes riftsawn versus quartersawn, and this entry will help clear it up for you.

To recap, a board is referred to as quartersawn when it is cut radially from a log. As you get further away from a radial cut on a log, the angle of the grain/tree rings will start to get further away from 90 degrees. And as that angle starts to become less and less perpendicular to the face of the board, the classification of the board goes from “quartersawn” to “riftsawn.” These diagrams should make it clear:

“True quartersawn” means 90-degree, radial grain, but these days the “quartersawn” term has been sliding–it won’t be unusual for you to spot a board labeled “quartersawn” where the grain angle is all the way down to 60 degrees. These two boards, for example, were listed by a supplier as quartersawn, even though we can see the angle of the grain seems to wander past that 60-degree boundary:

Endgrain Photo 1

A sawing diagram illustrates this more graphically. The drawing below left allows you to see how they’re letting the modern-day definition of quartersawn slide a bit, while the sketch below right shows the ideal:

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