WoodSense: Spotlight on Rosewood

History in woodworking

The Chinese revere rosewood and have used it to make exquisite furniture since the 16th-Century Ming Dynasty. China still ranks as the world’s largest consumer of rosewood. Today most woodworkers, find rosewood too expensive as a primary furniture wood. It’s more likely used as veneer or inlay, or for small, prominent parts such as knife and tool handles. Rosewood turns well, and small scraps are used to make pens and the black pieces in the finest chess sets. Rosewood’s excellent acoustic properties are great for making guitars and other musical instruments, like marimbas, that rely on wood vibration to produce sounds.

Where the wood comes from

Many rosewood offshoots grow in other parts of South America and in Central America. The common titles typically indicate the country of origin, though some species have a wider range than their names suggest.

Out of necessity due to restrictions, many woodworkers turned to two Indian species—Dalbergia latifolia and Dalbergia sissoo that are almost indistinguishable from each other. Plantation-grown  Dalbergia latifolia, often marketed as “Sonokeling,” grows primarily in East India and is sold either as East Indian rosewood or just rosewood. Dalbergia sissoo, sold as Indian rosewood, grows in northern and western India.

Selecting a species

Except for Brazilian rosewood, other varieties are relatively simple to obtain, but they can be expensive. Although family traits make the wood easily identifiable (dark heartwood and creamy sapwood that mellows when exposed to light), the Dalbergias vary in color and grain, even from one board to the next. Considering the investment ($15-20 BF and up) it’s a good idea to select the stock in person if you can.

Luthiers love Brazilian rosewood’s acoustic properties as well as the attractive colors ranging from a honey-gold to a dark chocolate brown. Indian rosewoods are beautiful in their own right, but don’t have the color range of Brazilian—they are typically a reddish-brown.

Working rosewood in the shop

Brazilian rosewood earned its reputation for its beauty and working qualities. Despite being very hard and dense, the wood is flexible and unmatched as a “tone wood”—perfect for luthiers. The rosewoods share myriad qualities, including outstanding turning and shaping characteristics, exceptional stability, and excellent decay resistance. The Indian rosewoods perform most like their Brazilian kin, but there are some noteworthy differences with the other siblings. Honduran rosewood is difficult to work with hand tools, and while it machines well, it dulls cutters quickly. Burmese rosewood is usually straight grained and easy to work with hand tools or machines, but it also blunts sharp edges in a hurry.

Dalbergias contain extractives that can sometimes hinder adhesion with water-based glue. To avoid adhesion failure, mill or sand the edges, and then wipe the surface with naptha before gluing. Epoxy or polyurethane glue work well.

Despite its lovely fragrance, rosewood dust can be quite irritating. Depending on the species, symptoms range from dermatitis to skin lesions, and minor sinus irritation to asthmatic-type reactions. The Dalbergia extractive is a very potent allergen for some. In some cases, musicians who experience only minimal exposure to the wood—by way of skin contact with chin rests or fretboards—have developed skin rashes. As with any wood, wear a NIOSH-approved dust mask and use good dust collection.

Finishing

True rosewoods—and rosewood substitutes—can be polished to a shine, but the resinous, waxy sawdust gums up sandpaper. A cabinet scraper works great for removing mill marks. Wet-sanding is another good option. The extractives can prevent oils and oil-based polyurethanes from curing properly. Test before finishing, or seal the wood with shellac. Rosewoods vary when it comes to grain. Depending on the sample and species, you may need fillers to achieve a super-smooth finish.