It’s easy to dismiss Engelmann Spruce as just another softwood. It’s cut for studs and framing lumber, sliced for plywood, and is an excellent pulpwood for paper making. Boring perhaps, but it does excel in one specific area – as a tone wood for musical instruments.
Engelmann Spruce is found growing in the Rocky Mountains of western North America. Alberta, British Columbia and the states of Washington, Oregon, Idaho and western Montana are the prime locations for harvesting. The tree prefers to grow at higher elevations. It is usually found in mixed forests with sub-alpine firs. Pure stands of Engelmann are rare; it likes to grow interspersed with other species.
Engelmann typically grows from 45 to 135 feet tall with diameters approaching 30 inches. Exceptional individuals can achieve heights of over 200 feet with 4 foot diameters. This tree doesn’t self prune like many soft woods, so the wood produced can be knotty. It dries easily with little degrade or staining.
Like its close relative Sitka Spruce, it has a high strength to weight ratio. It has medium to fine texture. The grain is straight but can be irregular around knots. The heartwood is a almost pure white. The sapwood is small, often indistinguishable from the heart. The medulla-like rays on quarter cut material can be quite visible for a softwood giving the wood a ‘silky’ appearance.
Engelmann Spruce works easily by hand or machine. The wood should not be overly dry (not less than 9% moisture content) as it can become brittle. It absorbs glue quickly which can result in starved joints if too much time is taken during the glue up. Nails and screws should be appropriately sized. It can blotch when stained. I would recommend a sealer or gel stain.
Engelmann is an excellent tone wood. It is used for piano soundboards, violin tops and most famously as acoustic guitar tops. In all of these examples, the soundboard or top is tasked with transmitting the vibration of the strings and projecting them from the instrument to a receptive audience.
Engelmann Spruce end grain
Engelmann has a high strength to weight ratio. Tops and soundboards made from it can be made very thin which allows for an efficient transfer of energy in the form of sound waves from the strings to our ears. Engelmann harvested from old growth exhibits the straight knot, free grain that is conducive to fine tone woods. Unfortunately, these trees are rare and pushes the price of Engelmann tone woods higher.
Some luthiers consider Engelmann the best substitute for an increasingly hard to find European Spruce. Other instrument builders prefer Engelmann for it its colour. Sitka Spruce can have a yellow tone. A guitar with an beautiful Engelmann linen white top contrasting with a darker back and sides can produce a striking instrument compared to its Sitka cousin.
I have focused on the unique tone wood property of Engelmann Spruce in this article; however, unless you are an instrument builder, you probably won’t select this wood for your projects. I might not build a guitar or a violin, but I think all woodworkers can draw inspiration from the wide variety of disciplines that woodworking offers. Admiring the crisp white Engelmann Spruce top of a well made guitar shows you appreciate the beauty of wood and all it can offer.