Ceramic Head Recorder

Ceramic wind instruments are not a novelty. They are to be found in museums all over the world among folkloristic musical instruments. Up to now however, ceramic concert recorders do not seem to have been produced. This may well be due to the difficulty of monitoring the dimensions of the ceramic pieces during the firing and the drying processes and thus the inherent difficulty of controlling the sensitive parameters of the wind-way affecting the pitch of the instrument and its tuning.

In 1993, after several attempts at trying to overcome the above-mentioned difficulties, Marco Piga and I succeeded in making the first ceramic concert alto recorder. The aim of our experiments was to find a new quality of sound but what we discovered was that, while the sound does not differ significantly from the traditional wooden recorders, ceramic material is ideal for making recorder heads and blocks. And that this provides a solution for transforming an instrument that is highly sensitive to climatic conditions into one that is reliable under all circumstances.

CHARACTERISTICS OF MATERIALS IN RECORDER MAKING

Let us now compare the characteristics of the different materials used in making recorders.

FINISH

There are problems with fibrous woods, especially the softer ones but also with the harder, exotic woods if not of the best quality. This characteristic has influence on the attack of notes because when the wind-way is not smooth articulation is more difficult. Ebony and boxwood are the best woods; plastic recorders are also good from this point of view, whereas both the windway and block of ceramic recorders can be made perfectly smooth.

STABILITY

All wooden recorders are subject to warping; old instruments, especially if made in boxwood, are more likely to be banana shaped than straight as a rifle barrel. There are two types of warping: temporary warping which occurs when the recorder absorbs humidity while being played. This can be considered completely reversible as long as the instrument is used properly and for a maximum of 2 - 3 hours a day. There is also permanent warping which has to do with the nature and formation of the wood and which manifests itself gradually over time, although the process can be speeded up and accentuated by excessive use and extreme climatic changes.

All recorder players know that a nice wooden instrument does not remain the same especially when excessively or irregularly played. They also know that it is necessary to have the recorder periodically checked by the maker, although this can be a risky job. At normal temperatures plastic retains its shape.

Ceramic holds its shape at any temperature, regardless of use. While playing, the ceramic head can be mistreated at wish; the instrument can be played for days without interruption and, if necessary, the wind-way channel can be washed with soap and water whereupon it looks as good as new.

PERMEABILITY

This is the most important characteristic of a material used in making the wind-way. It greatly influences the stability of the acoustic qualities. Since the wind-way surfaces are, not only initially, colder than the air blown in by the player, they cause some condensation and a consequent formation of water drops of varying degrees of size and persistence, depending on the permeability of the surface. The superficial tension, which holds the drops near the wind-way outlet, depends on the material's porosity and on the smoothness and chemical characteristics of the surface.

In a wooden wind-way the porosity of the material is not completely positive because, although on the one hand it facilitates elimination of the drops through absorption, on the other hand the consequent humidity increases warping and deforms the wind-way path as well as altering its size.

After regular use of a wooden recorder (a "running in" period) a natural coating is formed, making the surfaces less porous whilst helping drop-elimination through slipping over the surfaces of the wind-way.

Nevertheless, in very cold places such as churches, often used for early music concerts in winter too, even a well run-in recorder can be affected by condensation which makes it particularly difficult to produce the highest notes.

In the case of plastic instruments (a completely impermeable material) and industrial recorders made with wax impregnated wood, this problem is so great that professional use becomes impossible. Even recorders made of certain untreated woods, such as grenadilla and ebony (naturally waxy woods), are affected by the same problem; the surface tension keeps condensation drops in the wind-way channel and so the player often has to suck on the instrument in order to get rid of the moisture to be able to produce the higher notes.

This appears to be an insoluble problem with the historical materials, and this, together with the other problems described, has certainly contributed to the disappearance of the recorder from the orchestral scene. The problem is completely solvable however - but only by using an absorbent and shape-retaining material such as ceramic. This material is porous and able to absorb 25% of its own weight even at low temperatures, therefore preventing condensation and allowing the sound to come out easily even after many hours of playing. Ceramic recorders have a remarkable ability to produce the higher notes with extreme ease.

LIFE SPAN

The life span of a wooden recorder is still uncertain. It is often thought that a valuable wood lasts longer. I personally believe that a recorder's life depends on how one uses it.

There is still not enough experience of plastic (although we might ask whether it is important that a plastic recorder lasts a long time!).

As regards ceramic we have no doubts: ceramic relics found on the bottom of the sea in perfect condition are proof that ceramic materials can last for at least 3000 years. That's not bad, is it?

One last thing; we all know that ceramic is fragile, so the ceramic recorder's head-joint shouldn't be dropped or knocked just as with any other musical instrument. However a wooden recorder can suddenly crack by itself (many players have experience of this) whereas a ceramic instrument will never play that particularly nasty trick on its owner!

© Copyright 1996-2001, Francesco Li Virghi
This page was last updated on 08/08/1999
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