Potential use of Libidibia ferrea and Poincianella pluviosa woods for bows of string instruments

Abstract

To determine the potential for use in the manufacture of string instrument bows, the anatomical features, as well as physical, acoustic and chemical properties, of Libidibia ferrea (pau ferro) and Poincianella pluviosa (sibipiruna) wood were compared against those found in Caesalpinia echinata (pau brasil) wood, the established species for modern bow-making. Recent studies recommend relevant parameters of bow quality, such as wood anatomy, physical and mechanical properties. Based on its similarity to C. echinata in terms of ray width, fiber length, specific gravity and performance index (bending stiffness for a bow of given mass and geometry), P. pluviosa presents higher potential for bow-making than L. ferrea. However, P. pluviosa trees grow in plantations with tight spacing, resulting in higher wood density when compared with trees from natural populations. Heartwood color of L. ferrea is closer to the reddish–brown heartwood of C. echinata, thus differing from P. pluviosa. As such, heartwood similarity could be a positive factor for its acceptance by musicians, who are accustomed to bows made with C. echinata wood. However, based on the initial analysis, L. ferrea may show lower workability by its hardness, making it difficult to manufacture bows. Extractive content did not differ between L. ferrea and P. pluviosa and was lower than that of C. echinata. Lignin was higher in C. echinata and lower in P. pluviosa. Holocellulose was higher in P. pluviosa and lower in C. echinata. Overall, preliminary analyses indicate that both woods have sufficient potential to produce bows adequate to the needs of beginners and amateur musicians.