It shouldn’t shock you that well over 80% of string instruments cracking repairs by luthiers are related to weather conditions changes; mostly, abrupt but sustained humidity fluctuations, and as such, knowing why and how to humidify a cello will help you guard against humidity effects on cello and should rank top among your cello care and maintenance actions.
Understanding humidity effects on cello
Just like with human beings, humidity (which is basically water vapour amount in the air at any given temperature reading) level range ideal with cellos and most other string instruments is 40% – 60%.
Subsequently, extreme cases of increase or decrease of humidity in the air ultimately results to devastating effects on your cello if not countered in time in that, they result in potentially destructive expansions and contractions respectively of the stringed instruments’ parts.
Just as humans naturally adapt when humidity levels vary, so do cellos too. There is quick adaptation to humidity change in the air by the woods (the two types; maple and spruce) that make the cello because of their porous, hygroscopic and sponge like nature, thus absorbing and retaining moisture, though at differing rates.
The adaptation is further aided by the cello’s arched shape of back and front which increases susceptibility to expansion and contraction.
While mild weather/climatic changes may mostly only affect the tuning of the cello, the eventual effects of considerable humidity levels drop, and depending on severity, range from cello opening at the seams, cracking either at front or back, warping, strings shortening or even, splitting besides the obvious first casualty being “death” to the cello’s good sounds.
Unlike somewhat tough adhesives like synthetic glues, most common collagen based adhesives used for sealing the cello wood seams’ like hide glue are not as strong after drying out and under severe stress caused by the very dry air.
Subsequently, they don’t help much with holding together incase of shrinking caused by unabated low humidity results in opening at the seams. This opening at the seams under these climatic pressure stresses is sort of a “safety valve” for the instrument.
However, strong adhesives under similar conditions and extensive shrinkage, because of their tight gripping of the cello woods eventually cause cracking of the instrument as the seams won’t split open.
You are better off if a cello suffers opening at the seams than cracking altogether. Repairs for that are obviously costly while unfortunately, your highly priced piece is hugely devalued. And what a heavy price to pay as a result of humidity effects on cello.
In extreme cases, extensive warping makes even the fingerboard to rise overly very near the strings making it impossible to make any distinct notes. This is as a result of the neck angle change caused by neck root shrinking. In the worst cases, it potentially can mess up the instrument irreparably.
On the contrary, cello wood plates slacken due to the expansion resulting from rise in humidity as well as distorting the sound post’s position, neck and scroll.
Humidity fluctuations’ effects extend to the cello bow, by distorting the bow’s camber as well as bow hair which sadly, necessitates a bow rehair. The effects extend even to cello strings which could even suffer corrosion.
One more thing, when the rosin becomes too sticky, just be alerted that there is a real change in humidity and as such, prepare appropriately to minimize the effects of the changes.
However, it’s critical to note that extremes of temperature or moisture levels don’t have as extensive stressful effects on the instrument as much as the rapid weather condition changes.
Safe ways of guarding against humidity effects on cello
As explained here above, too low or too much of humidity, overly sustained and unmitigated will in both cases have adverse effects on your cello, just like with any other string instrument. Therefore, the need to keep your cello in an adequately humidified room/place always can’t be overemphasized.
Dry winter times are especially unforgiving and bring with them harsh humidity effects on cello(s), and potentially destructive to most string instruments if no proper mitigation measures are employed.
This is mostly because, with low outside temperatures, indoor heaters and central heating of rooms are deployed to warm the rooms. Subsequently however, this results in drying out moisture in the air. Eventual result is an extensive drop in humidity, sometimes to even below 20%.
- You start by knowing the indoor humidity of your cello playing room or even storage rooms at all times to enable you respond appropriately.
This you can do by investing in a good, battery powered digital hygrometer. Most are easily portable and therefore easy to keep in the cello case.
Another accurate test for humidity in the air, particularly in your cello case is the hair-tension hygrometer. Hair horse strand under tension is strapped on the device which accurately monitors and signals moisture changes.
- Having established that the room’s humidity is low and as such needs intervention to restore/re-create the ideal and safe humidity levels for your string instrument, get a room humidifier kick in for the moisture output.
While with some humidifiers you would need to manually keep varying the humidity levels needed, some come with humidistats already built-in; all you need to do is pre-set the desired moisture levels.
Any indoor humidity drop below the set levels, it automatically triggers moisture output to the air and moisturize it sufficiently.
If not playing the instrument, always keep the cello in its case and ensure to have a cello case humidifier. Some cases have inbuilt humidifiers to do the job. However, they come at a cost although some have been adjudged inaccurate.
You may be asking how often to recharge your humidifier? Well, once every week with de-ionised or distilled water is safe a frequency just so it doesn’t run out unexpectedly.
The brand with most positive reviews for both humidity testing and humidification are the Stretto Hygrometer and Stretto Humidifiers respectively.
- Besides using mechanical humidifiers, another commonly used humidifier is the Dampit cello humidifier, loosely referred to as “green plastic snake”.
It has sponge like stuff enclosed in the rubber sleeve. All you do is, soak it in water and wring it out leaving it mildly damp, then slot it in through the F-hole.
Subsequently, dampness keeps the air around the stored cello moisturized. It has proven an equally convenient safeguard against humidity effects on cello.
The challenge with this mode of humidification is that, because of the stationery position of the cello, the unavoidable water drop collection will be on one spot which could be counterproductive, considering the detailed effects of water on the cello woods.
That is however determined by the duration of use but it surely is gradual and may not manifest instantly. Molds are also likely to develop which is potentially a health risk to the cellist.
- While high humidity may not be as common as low humidity, when it does happen, your cello will definitely suffer the effect as explained earlier in the article. It is a case of moisture level in the air surpassing the ideal upper limit of 60%.
Using a dehumidifier will help by sucking the excess moisture from the air in the room to the recommended level.
- If you have had to travel, say for a performance, and you are certain that the climate there is different from your turf, them it would help to arrive in good time to help acclimatize your instrument.
- Ensure to never leave the cello in places prone to extreme fluctuations in humidity changes in the air due to temperature changes; places like cars, basements especially during transitions from daytime to nighttime and vice versa.
- Always, when not in use, as an anticipation and safeguarding measure against humidity effects on cello, the cello should always be kept in a lockable/closed cello case. While it may not be the ultimate protection, it definitely minimizes sudden temperature and humidity change effects.
- Using a microfiber cleaning cloth, ensure to wipe off rosin dust from your instrument, be it the strings, the body and even cello bow.
Rosin has high affinity to moisture and as such, wiping off eliminates the risk of rosin dust, settled on any part from gathering and holding harmful moisture.
- Don’t use or store the cello near open flames, heaters, air conditioner vents or any radiators. These have the effect of drying out the moisture in the air within the room, resultantly decreasing the humidity.
Conclusion: You are guaranteed of a long life with your cherished instrument’s tonal beauty, play-ability and ease of response if you learnt how to guard against humidity effects on cello whether in the room, travelling or even storing.