Caesalpinia echinata Lam. (pau-brasil) is a Brazilian tree with symbolic character for Brazilian forestry, which is at risk of extinction because of illegal logging activities and exportation as raw material for bows of string instruments. Additional studies are required to select substitutes for pau-brasil, i.e., other wood species are being sought with potentially suitable characteristics for bow manufacture. The present paper is dedicated to the evaluation of six native Brazilian woods by comparing their anatomical features, specific gravity, speed of sound propagation, and dynamic modulus of elasticity in relation to the corresponding properties of C. echinata that are considered as standard for bow manufacture. The results showed that length, diameter, lumen diameter, and wall thickness of fibers are the most important variables contributing to specific gravity. Additionally, ray dimensions influenced sonic velocity. The values of dynamic modulus of elasticity are directly related to dimensions of rays and fibers. Among the six woods included in this study, Dipteryx spp., Handroanthus spp., and Hymenaea spp. were considered as the best alternatives to C. echinata wood as sources of bow construction. The bows from the first two woods were already tested by professional musicians and their suitability was certified. The Diplotropis spp. wood also showed promising characteristics. Mezilaurus itauba and Astronium lecointei do not have the necessary properties for bows.

While the wood Caesalpinia echinata (pernambuco wood) is traditionally used in the manufacture of bows for string instruments, wood of other genera such as Handroanthus (syn. Tabebuia) and Manilkara are also used in bow making, but still on a very small scale. This study aims to evaluate the anatomical, chemical, physical, mechanical, and acoustic characteristics of these two latter woods, establishing their potential for bow making. Length, frequency of vessel elements and rays, and the higher percentage of fibers influence the density, modulus of elasticity, modulus of rupture, and the speed of sound propagation, whereas the content of lignin influence the sticks’ stiffness. It appears that Handroanthus bows can provide quality equivalent to that of pernambuco wood. Despite its appropriate heartwood color and texture, Manilkara provides bows of inferior quality.

In this paper we investigate the influence of extractives, lignin and holocellulose contents on performance index (PI) of seven woods used or tested for violin bows. Woods with higher values of this index (PI = √MOE/ρ, where MOE is modulus of elasticity and ρ is density) have a higher bending stiffness at a given mass, which can be related to bow wood quality. Extractive content was negatively correlated with PI in Caesalpinia echinata, Handroanthus sp. and Astronium lecointei. In C. echinata holocellulose was positively correlated with PI. These results need to be further explored with more samples and by testing additional wood properties. Although the chemical constituents could provide an indication of quality, it is not possible to establish appropriate woods for bows solely by examining their chemical constituents.

For nearly two hundred years, Caesalpinia echinata wood has been the standard for modern bows. However, the threat of extinction and the enforcement of trade bans have required bow makers to seek alternative woods. The hypothesis tested was that woods with physical, mechanical and acoustic properties similar to those of C. echinata would have high potential as alternative woods for bows. Accordingly, were investigated Handroanthus spp., Mezilaurus itauba, Hymenaea spp., Dipteryx spp., Diplotropis spp. and Astronium lecointei. Handroanthus and Diplotropis have the greatest number of similarities with C. echinata, but only Handroanthus spp. showed significant results in actual bow manufacture, suggesting the importance of such key properties as specific gravity, speed of sound propagation and modulus of elasticity. In practice, Handroanthus and Dipteryx produced bows of quality similar to that of C. echinata. MADEIRAS COM PROPRIEDADES FÍSICAS, MECÂNICAS E ACÚSTICAS SEMELHANTES ÀS DE Caesalpinia echinata POSSUEM POTENCIAL COMO MADEIRAS ALTERNATIVAS PARA ARQUETEIROSRESUMO: Por quase 200 anos, a madeira de Caesalpinia echinata tem sido referência para arcos modernos. No entanto, a ameaça de extinção e a proibição comercial têm motivado os arqueteiros a buscar madeiras alternativas. A hipótese testada foi a de que madeiras com propriedades físicas, mecânicas e acústicas semelhantes às de C. echinata, teriam grande potencial como madeiras alternativas para os arcos. Assim, foram investigadas Handroanthus spp., Mezilaurus itauba, Hymenaea spp., Dipteryx spp., Diplotropis spp. e Astronium lecointei. Os resultados mostraram que Handroanthus e Diplotropis apresentam o maior número de semelhanças com C. echinata, mas apenas Handroanthus teve resultados significativos na fabricação dos arcos, sugerindo a importância das seguintes propriedades chave: densidade aparente, velocidade de propagação do som e módulo de elasticidade. Na prática, Handroanthus e Dipteryx forneceram arcos com qualidade semelhante ao de C. echinata.

In this paper it was investigated the organoleptic properties and machining of six potential woods for bows of stringed instruments and compared the results with those mentioned for the Caesalpinia echinata wood, the reference for modern bows. Thirty wood stores were visited in different cities of the São Paulo state to verify the commercial availability of these woods. We concluded that despite the traditionalism of the red tones in the woods for bows, woods with yellowish tones such as Handroanthus spp. and Dipteryx spp. or brownish such as Diplotropis spp. with appropriate properties, may offer alternative colors and textures to the musicians. It was observed that the Mezilaurus itauba and Astronium lecointei, woods with easy machining, have no potential suitable for bows. Regarding to availability, all woods tested are relatively easy to find nowadays in the wood market. Handroanthus spp. and Dipteryx spp. showed greater potential for making bows for professional musicians. The woods of Mezilaurus itauba and Astronium lecointei did not show good potential for bows