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| Wood & Care |
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| 1.
What is grenadilla? |
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What differentiates it from other woods?
On the world market this wood (Dalbergia melanoxylon, Leg.-Papilionaceae) has various names. In the English-speaking
world it is called grenadilla, sometimes referred to as "African blackwood", in French it goes under the name of "grenadille
d’Afrique" or "ébène mozambique", the Portuguese know it as "pão preto" (black wood) and in German-speaking countries
it is termed Grenadill.
In 1502 the Portuguese seafarer Vasco da Gama brought grenadilla from Mozambique back to his country as a replacement
for the costly genuine Asian ebony (Diospyros spp., Ebenaceae). It therefore
often happens that grenadilla is erroneously referred to as ebony. Ebony is a hard, dry, brittle wood with a very low oil and
resin content, and thus it is now scarcely used for making woodwind instruments.
At this juncture one should also mention cocuswood (Brya ebenus), well
known on account of its aesthetically pleasing appearance and belonging to the same family (Leg.-Papilionaceae) as grenadilla.
Because of the highly intensive exploitation of this already rare type of wood, imports have become a great rarity. Cocuswood is a
dry wood with a low oil content, so it cracks easily, and because of its components it can produce extreme allergic reactions..
Kingwood (Dalbergia cearensis), which also belongs to the Leg.-Papilionaceae
family, has an attractive, aesthetically pleasing appearance similar to that of coconut wood. However, it is brittle and has a marked
tendency to splinter, crack and split. The natural purplish-violet colouring is not durable in the long term, as the surface fades under
the influence of light and oxygen and then takes on a somewhat unattractive brown hue; even surface treatment cannot completely
stop this process.
In the production of my flutes I thus refrain from using cocuswood or kingwood. On the basis of my many years of experience I can
only confirm that grenadilla is the most suitable wood for woodwind instruments. |
| Abundance |
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The grenadilla tree is chiefly to be found in Central and Eastern Africa, especially in Tanzania and Mozambique.
It is a tree of the dry forests and the savannah, and grows to a height of about 5-8 m, whereby the trunk is up to
around 0.5 m in diameter and is free of branches. The grenadilla tree grows in isolation and has a ring-shaped
crown, and its branches are thorny. Grenadilla is self-pollinating, and because of the sparse stands it can freely develop.
Because of the region's long dry periods, which the grenadilla tree effortlessly survives, the areas of growth
are sparsely populated, thus the local need for this natural wood is very restricted.
The present abundance and the supply of new grenadilla far exceed demand, so no shortage is to be expected, nor is
the ecological equilibrium endangered by exploitation of wood resources. |
| Description of the wood |
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The trunk of the grenadilla tree is made up of the dead heartwood and the living sapwood, the colours of
which are sharply differentiated. The layer of sapwood is very thin and yellowish, and as it is worthless for
instrument-making it is removed when the tree is felled.
The backbone, and thus responsible for the tree's stability, is the trunk's heartwood. It is extremely hard,
and metabolic waste products are stored in it. It is thus rich in constituent substances, resins and oils - the
so-called heartwood substances - that determine the colour and structure of the wood and are dependent
on the soil properties of the location in question. The colour is brownish-violet to black and the pores are
medium-sized, scattered and almost completely full of dark heartwood substances, so that the surfaces seem
almost pore-free. |
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| Properties |
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The heartwood is extremely hard, very dense and heavy,
and because of its specific gravity of 1.3 g/cm3 it does
not float. Drying of grenadilla hardly causes any shrinkage.
As a result of its solidity, oil content and close grain - facilitating smooth surface treatment - grenadilla scarcely
absorbs any moisture from its surroundings, and being the heaviest, densest, most water‑resistant wood it is
thus absolutely ideal for woodwind-instrument making.
However, the selection and processing of the wood call
for broad knowledge and experience.
Flutes made of grenadilla have a "full tone which is particularly attractive in the high register" (Theobald Boehm).
Their characteristic timbre is bright, resonant, clear, elegant and rich in overtones.
For my flutes and piccolos I use only carefully-selected, well-seasoned, extremely close-grained and attractive
black grenadilla with the best tonal qualities.
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