Sitka spruce (Picea sitchensis)
The Sitka Spruce Tree
The spruce we sell is native to the coastal region of Oregon, Washington, British Columbia, and southeastern Alaska. Sitka spruce reaches 200 feet in height and lives for several hundred years.
Sitka spruce generally comes from private and public forests. Because the tree is prone to twist, loggers and sawyers find that only one in one hundred trees (or so) have the straight, twist-free trunks required for by instrument makers.
We try to sell spruce from sources who are engaged in selective cutting or are salvaging downed or standing-dead trees.
Sitka Spruce Wood
Sitka spruce is a softwood with an average specific gravity of .40, oven dry. With its relatively low weight and high strength, Sitka spruce was and is highly valued in the manufature of small airplanes. It has the highest strength-to-weight ratio of all tonewoods, a property many luthiers consider important. Its color ranges from creamy white to a heartwood with a light pinkish-brown hue.
Our Sitka Spruce Grading
In general, our instrument top woods are graded by the uniformity of growth-ring spacing and color. These are mostly aesthetic criteria. Lower grade sets may show light bands or streaks of color, and the spacing of the growth rings may be less even than in higher grades. Criteria like stiffness, runout, and how well a plate is quartersawn are much bigger issues, of course, but even lower grade sets will show very little runout, be well quartered, and stiff.
Flaws that might be acceptable when grading back and side set--for instance, a knot shadow--are cut around to preserve the strength and stability of the top woods.