Caring for your Marimba or Xylophone Bars
(Answers to significant questions about the maintenance of wood bar instruments) WHAT IS THE IDEAL ENVIRONMENT FOR MY XYLOPHONE OR MARIMBA? The bars of xylophones or marimbas undergo structural changes as a result of alterations in atmospheric conditions and the natural ageing process. Honduras Rosewood, from which most xylophone and marimba bars are constructed, is kiln dried to approximately 7% moisture content. That is known as Equilibrium Moisture Content (EMC) and is the point at which, given a specific temperature and humidity, the wood will not absorb or desorb water. However with alterations in the atmosphere, changes will occur in the wood. Higher temperatures and humidity (especially the latter) cause absorption and expansion, thus lowering the pitch. Lower temperature and humidity cause desorption and contraction, thus raising the pitch. These changes occur constantly everyday. This would indicate that the ideal environment is one where temperature and humidity is stable - in fact at 30% to 40% humidity and 18 to 22 degrees Celsius. Even when these ideal conditions occur, wood is still changing due to its constant decomposition. Since most of us do not have access to hermetically sealed spaces such as those found in many institutions of higher learning, it takes a little effort on our part to obtain and sustain the correct environment for our instruments. In the summer air conditioning and dehumidifiers should do the trick, in the winter proper heat control and humidifiers. In addition there are several practices which should be avoided. DON’T....store instruments in front of windows. Prolonged direct sunlight can do to marimba bars what frying does to bacon. DON’T....store instruments in front of or near radiators or heating ducts. Almost the same result will occur. DON’T....leave bars in cars or vans. They will either bake or freeze.
him accompanied by a note that goes something like this ”Some of the bar are a bit scuffed up. Would you please fix them”!! It really is rather difficult to repair a bar when one has to go digging in the bottom of the box to find the splinters. So, once again, the fault lies with the player and a little bit of common sense should solve the problem. If whatever is being done to the bars damages them - stop doing it! In most cases it is not what is being done to the bars but WHAT IT IS BEING DONE WITH. Usually what it is being done with are ACRYLIC MALLETS - which are more often designed for use only on Glockenspiels. The greatest enemy of any wood instrument be it xylophone, wood block, temple block or slit drum, is the ACRYLIC MALLET. This type of mallet ball is harder, denser than wood instruments, that is each time the instrument is struck - the ball causes a dent. These dents add up to cracked instruments. “But my conductor always insists on the hardest mallets!” In this case I suggest you tell the conductor you will be pleased to use such mallets if the bass section will replace their bows with chain saws!
WHY DO SOME INSTRUMENTS SEEM TO HOLD THEIR PITCH BETTER THAN OTHERS? Simply put , no two instruments, indeed no two bars, are exactly alike. How a bar reacts to its environment depends upon many factors - what part of the tree it comes from, how old the tree was when it was cut, what kind of soil the tree grew in, what the weather was during its life, how much sunlight reached it and when, what valley it grew in, which side of the valley.... etc, etc. It might be noticed that a xylophone made in 1928, might tend to hold its pitch better than, say, a marimba made in 1998. This is primarily because the xylophone has been ageing for 70 years while the marimba was very likely manufactured within a year of the wood being cut from the tree. Experience has shown that in spite of kiln drying, the subsequent natural ageing process renders the wood more stable as regards its tendency to absorb and desorb moisture.
Choice of mallets in relationship to bar damage is also a consideration on the marimba. This is especially true in the lower register where the bars are thinnest. The most frequently cracked marimba bar is the low “C”. I assume this is due to the out-ofcontrol left hands in Gordon Stout’s first Mexican Dance or successful attempts to indeed play fortissimo at the end of ‘Time’ by Minoru Miki. All wood bars, but especially low bars on a marimba, can withstand a blow of only so much force with a given density mallet ball, beyond which point they will break. So exercise caution and sensitivity. One should be able to ‘sense’ the force threshold of each bar with any mallet.
WHY DO BARS CRACK? Assuming the use of suitable mallets, a playing technique sensitive to the nature of the material and the structural integrity of the wood, the most probable cause of cracked bars is exposure to extremes in temperature and humidity, especially sudden drops in either. When wood is suddenly dried out, shrinkage occurs, and what is more, occurs in unequal amounts throughout the piece. This causes tension in wood which, when great enough, will cause splitting. A colleague of mine called one winters day deeply concerned as the low “C” on his ADAMS 5 Octave Marimba had cracked. This percussionist is thoroughly familiar with the proper choice and use of mallets and, knowing the quality of his marimba, we have to assume the structural integrity of the wood. He happened to mention that the instrument was stored at the college where he teaches and that the heat and humidifier in the building had been off for several days. This, then, was the answer. The sudden drop to and a very low temperature and humidity, then the raising of both when college resumed had caused a crack in the bar. WHAT CAUSES MY XYLOPHONE BARS TO CHIP AND SPLINTER? YOU!!! I am shocked at the number of xylophones I see with bars that have been virtually destroyed. A colleague friend who repairs instruments says that often a set of bars are sent to
The acrylic mallet has only fairly recently become popular due, perhaps, to its bright timbre. It does have its uses, on glockenspiels, etc., but will definitely damage your wood instruments. In the past, xylophones were generally played with hard rubber(wound and unwound) mallets. (There was, or perhaps still is, even a ceramic ball being produced. However, deadly accuracy was an absolute necessity as one stroke on a support post would cause the ball to shatter into chunks of lethal, flying rock!) As anyone who owns some of the original rubber mallets manufactured earlier this century will attest, rubber can be extremely bright. Some of the only hard mallets available today that wont damage your bars are the Chalklin Ragtime (MSGJ3) or Hard (MSGJ2) polyball mallets, or the Malletech BB34 (Bob Becker) or OR39 Orchestra mallets.
WHAT SHOULD I USE TO CLEAN THE BARS? SHOULD I WAX THEM? The best substance with which to clean wood bars is a high quality non-caustic furniture polish. It would be wise to apply a professional quality paste wax to older instruments to help preserve the finish. Please note that new instruments have already been treated at the factory. While on the subject of finishes, one should avoid contacting the bars with the skin - as the salt, especially from sweaty hands, slowly eats away the finish. IN CONCLUSION Marimbas and xylophones are not difficult to care for. It takes only very basic knowledge about wood and a bit of common sense. These instruments are of great aesthetic and monetary value and, as evidenced by the beautiful condition of many instruments approaching 80 years of age, will, if thoughtfully and lovingly cared for, last far longer than you or I. Adapted by Graham C. Johns JAM Percussion 8 Dakota Business Park Skyhawk Avenue LIVERPOOL L19 2QR Tel: 0151 494 1492 Fax: 0870 1275 855 Email: mail@jampercussion.com Web: www.jampercussion.com