All conservation treatments, including cleaning, should be fully described in a treatment report and the information carefully kept for future reference. Before and after photographs are recommended, together with those showing the treatment in process. Instruments in playing order that require regular tuning and/or maintenance should have their own log book into which all observations about their condition and maintenance interventions are entered. The amount of time that an instrument is played should also be recorded, together with the date and name of the player.
Each type of instrument has particular needs for a benign environment. The elements in each case that need to be considered include: the temperature, relative humidity levels (the amount of water vapour in the air, expressed as a percentage of the maximum amount that the air could hold at the given temperature), and light levels. The exclusion of insect pests is also fundamental to maintaining a safe environment. All of these elements require effective and regular monitoring, and there are many ways to implement this at a relatively low cost.
All instrument types need to be handled with care. Often it is appropriate to protect the surface of the instrument from moisture, acids and oils on our skin by using cotton or disposable nitrile gloves. Moving parts like keys, valves and tuning pins or pegs, should not be operated until inspection confirms that it is safe to do so. Instruments like clarinets that have distinct sections are at particular risk since they can appear, deceptively, to be securely attached to each other. The same may be true of brass instruments with their separate crooks or mouthpieces. When separable parts become stuck together, the temptation to force them apart must be resisted. Likewise, separated parts must not be forced back together. Specialist assistance should be sought.
It is a fundamental part of a Museum’s remit to ensure that objects are accessible for study and research. Many researchers are experienced in the proper handling of instruments, but there have been cases of damage to museum instruments resulting from inappropriate measuring techniques and mishandling. An experienced musical instrument curator will be able to assess the risks of any proposed examination, the skills and experience of the researcher, and the potential information gain to scholarship from a proposed examination. The CIMCIM Recommendations for Regulating the Access to Musical Instruments in Public Collections: 1985 are a good departure point. They are helpful in managing and formalising research visits and can assist in clarifying the issues relevant to your instrument(s) or collection.
Click on the type of instrument that requires your care:
How should a brass instrument be handled?
An instrument should not be separated from its mouthpiece(s), case, and any supplementary bits of tubing or accessories. Museum staff ordinarily handle objects with gloves, and this is particularly important for highly polished brass, where finger-prints can be impossible to remove without taking off a surface layer of metal. Disposable nitrile gloves are the safest and are standard equipment in museums. Cotton gloves are more comfortable but transmit sweat: if used, they should be washed after a short period. Care is needed with trombones as the slides can slide off.
How should a brass instrument be cleaned?
Removing dust, cobwebs, and other gross dirt is usually straightforward, although extreme care is needed with the painted surfaces occasionally found inside the bell. Residues of old polishing agents and hardened lubricants can be carefully removed with wood hand tools. Some instruments have been lacquered in the past and look unsightly when the lacquer inevitably breaks up. Advice on removing lacquer should be sought from a conservator. A long-term approach should be adopted before deciding to polish a brass instrument. Polishing removes original material, and a regime of repeated polishing is not sustainable. Surface corrosion of brass to a brown colour is harmless and actually protects the surface. The form of corrosion which does need to be addressed is verdigris: this progressively worsens and any green spots should be removed mechanically under supervision by a conservator. Intergranular corrosion of brass presents as cracking, commonly in the very thin brass sheet found in some instrument parts. This problem is exacerbated by ammonia-based polishing agents and calls for extreme care in handling. If the decision is taken to polish an instrument, the subsequent corrosion of the surface can be delayed by applying a thin coating of micro-crystalline wax (‘Renaissance Wax’).
How should a brass instrument be lubricated?
Lubricants tend to harden and the question deserves attention for the long-term preservation of a brass instrument. Freely moving parts such as trombone slides and valves need lubrication when an instrument is played, but for museum storage old lubricants should be removed and the parts kept dry. Tightly fitting parts, however, particularly tuning-slides, can sieze up in a matter of months. Old greases should be removed and replaced by medium-viscosity silicone wax: this is much more stable than commercial slide greases which should not be used on museum instruments. Any lubrication should be fully described in a treatment report and the information carefully kept for future reference.
What should be done if a brass instrument is to be played?
For a discussion of the general issues surrounding the playing of instruments go to: How do I decide whether or not to play. With brass instruments the risk of sudden serious damage is low, but incremental damage is inevitable in playing. Exterior surfaces are handled, moving parts need to be lubricated, and interior surfaces are subject to the corrosion-inducing moisture from the player’s breath. Damage can be limited by subsequent cleaning and drying, but a careful risk assessment is required in advance to determine if the benefits of playing justify the cost in terms of wear and incremental damage. Any playing and associated treatment of the instrument before and after should be fully described and the information carefully kept for future reference. It is advisable to record the instrument if it is sounded.
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What’s the best environment for a string instrument?
Stable environmental conditions are best for wooden stringed instruments. Ideally, the relative humidity should not drop below 40% or rise above 65%, but quick fluctuations, even within this range, could cause damage. Temperatures should remain within the range 13-20°C and again, rapid changes should be avoided. Indoor conditions that are comfortable for people, especially in the winter time, are likely to be too dry and warm for most string instruments. If kept in such conditions, moisture should be added to the atmosphere using a humidifier that has the capacity to cope with the size (volume) of the room.
Where and how should I store a string instrument?
String instruments are best stored away from sources of heat/air conditioning, strong light and outside walls. A case can act as an effective buffer to environmental change, and for larger instruments even a simple cloth cover can provide some protection. Instruments where the strings are not slack, even those kept below their playing pitch but still under tension, are more vulnerable to instability and adverse environmental conditions. Special care should be taken to provide them with safe surroundings. The extended necks on instruments like violins, viols, double basses, theorbos (lutes with extended neck) and guitars, need supplementary support so as not to distort under the influence of gravity. This can be provided with rolls or tufts of (acid-free) tissue paper or Plastazote® (see below). Plastic coverings (e.g. cling film, bin bags) inhibit air circulation and can encourage the growth of moulds that stain and mar the appearance of wood. Bubble wrap, in particular, should be avoided for long term storage since it can also leave its impression on varnish or other surface finishes.
Tyvek®, a brand of synthetic flashspun high-density polyethylene fibres, can be recommended for safe storage covering and Plastazote®, a closed cell polyethylene foam blown with nitrogen, can be recommended for giving cushioning and support. Ideally, a layer of acid free tissue paper or Tyvek® should be introduced between the object and these storage materials. For advice on where to obtain conservation materials see the Useful Links section on Conservation Materials and Information.
How should I clean a string instrument?
A soft brush with long bristles, once the metal ferrule has been covered in masking tape, can be used to remove surface dust and dirt. Avoid using feather dusters because they can easily leave marks, and cloths of any description can catch and pull on edges. More ingrained dirt could provide evidence about performance practice or a pattern of use, and expert advice should be sought before attempting to remove it. Solvents of any kind, including water, should only be used under specialist supervision, since these could easily damage the surface finish or patina. A stringed instrument with composite decoration, like inlaid ivory, brass, mother of pearl or marquetry, will almost certainly require a variety of conservation techniques in order to treat each material correctly and to protect the surrounding wood. Great care should be taken not to dislodge any loose pieces and to keep together any pieces found detached. A conservation vacuum cleaner on a low suction setting can be used to pick up dust dislodged by brushing. Choose a narrow nozzle and cover it with netting to catch anything accidentally detached. Do not bring the nozzle into direct contact with the instrument.
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STRINGED KEYBOARD INSTRUMENTS (e.g. pianos, harpsichords, clavichords)
What’s the best environment for a string keyboard instrument?
The specific guidelines given above in String Instruments pertain equally to stringed keyboards. Maintaining safe and stable environmental conditions is the single most important thing that you can do to ensure the well-being of stringed keyboard instruments.
Stringed keyboards maintained in playing condition are under constant tension exerted by their strings. This can exceed a ton in large pianos, but even smaller, more lightly built instruments are resisting tensions near to the limit of what their exclusively wooden structures can safely bear. This constant tension makes them peculiarly vulnerable to the damaging effects of adverse and changeable environmental conditions. The rest of this section deals with the heightened needs of keyboard instruments maintained in playing condition.
How often should I tune my keyboard?
It should be noted at the outset that early keyboard instruments such as harpsichords and clavichords behave quite differently to modern pianos, even in the way that they are tuned, and experience with one type confers no expertise in the other.
A stable environment will maximise the tuning stability of stringed keyboard instruments. Large metal framed pianos may require tuning no more than twice a year, but more lightly built instruments with wooden frames are likely to need more frequent attention. Harpsichords, clavichords and early pianos (without metal frame) will probably need to be tuned twice a month or more. They will certainly require tuning whenever they are moved and immediately before any performance or recording. Instruments that have been routinely kept at their reference pitch and regularly tuned, will, naturally, behave much more reliably and predictably in performance situations. If a playing instrument needs to go into long-term storage, consult a professional keyboard instrument conservator well beforehand so that a safe and practical care-plan can be devised.
I have been asked to change the pitch of my keyboard instrument. What should I do?
It is a serious step to change the overall pitch of a stringed keyboard instrument, even by a small amount.
The pitch of different keyboard instruments can vary enormously, but every instrument has an optimum pitch level for which it was designed, dictating both the sounding length of the strings and their materials. Its ‘normal’ pitch may differ from modern standard concert pitch (a’=440Hz), and it is not unusual for earlier instruments to rest a semitone or more lower or higher. Changing the instrument’s pitch may cause it to feel and sound differently and it may not respond as reliably to the player. Raising the pitch often causes string breakages, and the structure of the instrument may not be able to withstand the increased tension of the strings. Counter-intuitively, lowering the pitch can also cause structural instability and string breakages. In addition, the returning of an instrument to its normal pitch after slackening the strings can cause breakages. The flexing of an instrument’s shape and joints caused by large variations in pitch can have a deleterious effect on the structure and an impact on the moving action parts. Instruments that have wandered significantly from their design pitch should be returned slowly and kept under observation throughout. This process can take days or even weeks.
How should I clean my keyboard instrument?
If possible, avoid letting the instrument accumulate dust and dirt. Keep the lid of the instrument down whenever possible and cover the exterior with a cloth that will not catch on paintwork or veneers. Ask those who handle the instrument to wear gloves or to wash their hands in advance. Players should always be asked to wash their hands. Dust on the soundboard of a keyboard instrument is most difficult to remove not only because access is blocked by the strings, but also because the soundboard is thin (often no more than 3mm thick) and may be decorated. Sometimes a small bellows (e.g. a balloon pump) can be used to dislodge the dust. A soft brush with long bristles, once the metal ferrule has been covered in masking tape, can also be used to dislodge surface dust and dirt, although this can result in a streaky appearance. A conservation vacuum cleaner on a low suction setting can be used to pick up dust dislodged by brushing. Choose a narrow nozzle and cover it with netting to catch anything which may become accidentally detached. Do not bring the nozzle into direct contact with the instrument.
Retiring a keyboard instrument
Sometimes the accelerated rate of wear and tear and/or structural deterioration occasioned by use makes it both necessary and desirable to retire an instrument from playing condition. The rationale for this action should be discussed beforehand by a group including the curator, the conservator and an expert adviser. The conclusions should be documented both in a written and photographic form and then kept for future reference. Retiring an instrument from playing condition is best undertaken with the supervision of a specialist. The process will likely involve de-tensioning the strings, a serious step which will have an impact on the structure and which may initiate other irreversible changes in the instrument.