Eventually we all must face the reality of deterioration of grenadilla and other wooden instruments. Some of us can use our favorite instrument for many years before its performance becomes unacceptable. Others have to replace their instruments more frequently.
Obvious indications of deterioration include cracks and raised grain in the bore. Less obvious problems include a deteriorating scale, increasing intonation problems, and declining resonance. Overall pitch may drop below A-440 tuning. When these latter problems become extreme enough, the instrument is often declared "played out" or "blown out." The instrument has lost its voice.
What can a performer do to avoid or even reverse this deterioration? I would like to share my attempts to answer this question. The purpose of this clinic is to summarize 25 years of empirical data I have accumulated involving the use and effects of organic vegetable oils on grenadilla wood.
For most of my life, I have lived and worked in humid climates: western Washington state, Hawaii, and Massachusetts. When I moved to Denver, I was immediately struck by the instability of my instruments, especially my grenadilla clarinet.
It was obvious that the wood had changed dimensionally from its previous homes in humid climates. Tenon rings and some keys became loose, while other keys began to bind. Pad seal was compromised throughout the instrument. My clarinet was quickly reduced to something other than an artist quality instrument.
These very personal experiences in Denver led to my many years of investigation and experimentation. I began with a review of the available literature concerning oiling grenadilla. I found the authors consistently made two errors of analysis: (1) not identifying the type of bore oil involved; and (2) not recognizing the consequences of changing moisture content in wood caused by a change in local environment. I quickly realized that dry wood was and is a significant problem in dry environments.
Designing the research approach
When conducting experiments that rely on physical observation only, one has to be quite skeptical of results. It is very easy to see (or hear) only what one wishes. To minimize subjectivity, a better experimental approach is to prove or disprove a given hypothesis. Confirmation of results by other parties would reinforce the validity of the hypothesis.
Experiments involving physical changes in a musical instrument are relatively easy. However, experiments involving a change in its playing qualities are more difficult because of inherent subjectivity. In this latter case, I relied upon evaluations by many people over many years. If their perceptions consistently agree with my own, then there is a greater probability that playing quality changes have occurred.
To oil or not
In my earliest years as a repair technician in Colorado, I observed a dramatic increase in cracked wood, chipped tone holes, compromised bores, and poor key fit. How can one stabilize grenadilla wood to avoid these problems?
The most obvious option would be to use bore oil, but only if one could find a type of oil that really works. However, if one asks ten people whether or not to oil an instrument, one will probably receive ten different opinions. Unfortunately, opinions hold little value for me as a repairman unless they are backed by empirical evidence. Opinions usually result from a subjective evaluation and impart little useful information. Opinions I have heard often seem to be based solely upon opinions from othersopinions based on opinions. Let us attempt to separate opinion from fact concerning bore oils. There are two classes of bore oils: petroleum and (organic) vegetable. There are significant chemical differences between these oils.
Petroleum oils are hydrophobic. Chemically, petroleum oils will not mix with water. Since water has such a great attraction for itself, any petroleum oils will be "squeezed" out. This is one reason why petroleum oils are only adsorbed at the surface of the wood. If they are thin enough to penetrate into wood, they will quickly evaporate. Common uses for petroleum products include fuels, lubricants (for metal parts), and a base for industrial materials.
Vegetable oils, especially the lighter oils, are hydrophilic. While not considered soluble in water, they will incorporate water within their molecular structure. This is understandable because they are produced directly by plants in an aqueous environment. Common uses for vegetable oils include food preparation, skin care products, and agents for finishing and preserving (antique) furniture and stringed instruments. I would soon find that vegetable oils are absorbed by grenadilla wood. I began my "oil or not, petroleum versus organic" research by studying cork, cork being harvested bark from a tree.
Why not petroleum products?
I noticed that some natural cork tenons last a very long time while others prematurely failed and even disintegrated. Some incorrectly refer to this latter situation as "rotting." Common practice had it that one should grease cork tenons. The prevailing greases were petroleum-based. Without grease of any kind, the cork dries out and indeed disintegrates. With petroleum grease, the cork was still failing. Since rotting is a biological process, but petroleum grease is not a biological agent, the cork was not rotting per se. I needed to find an emollient that was not petroleum-based. I observed the results of greasing corks with both petroleum-based and organic-based greases.
I found that petroleum-based cork grease would cause natural cork to become increasingly hard and brittle. Often, the glue bond will fail. The cork will separate eventually from the tenon in long strips, or fracture into tiny pieces.
Tallow-based cork grease, as an emollient, keeps the cork soft and pliable. It does not appear to affect the glue bond. The difference is petroleum versus organic (animal) based grease; they are chemically different.
The apparent interaction between natural cork and tallow cork grease is an interesting phenomenon. This interaction indicates that natural cork and tallow share a commonality. They are chemically compatible, even though one came from a tree and the other from an animal. However, living tissue produced both. Trees produce nuts from which we express some oils, and plants produce the rest of an abundant variety of (organic) oils. All these plant-produced products, including grenadilla wood, have this commonality.
Organic materials are transformed by great heat and pressure over time into crude (petroleum) oil. This transformation eliminates the organic chemical characteristics that once existed before the crude oil was formed. Petroleum oils simply are no longer "organic"; they do not readily interact with organic products, including wood. The chemical qualities caused by transformation into petroleum oil allows the oil to be used for many inorganic uses, for example, as a lubricant for metal parts.
Initial statement of hypothesis
When I turned my attention to grenadilla bodies, I stated some initial premises that eventually would become my hypothesis. Because petroleum bore oils are chemically inert with wood, and do not interact with wood fibers, petroleum-based oils would neither minimize nor eliminate the following problems:
Compromised key fit and pad seal caused by "breathing."
Compromised bores caused by moisture and saliva damage.
Warping, cracking and checking caused by dry, brittle wood.
Chipped tone holes caused by dry, brittle, deteriorating wood.
Petroleum oils have no effect on reversing the problems associated with dry, brittle wood. This inability of petroleum-based bore oil to ameliorate the brittleness in wood parallels the inability of petroleum-based grease to ameliorate failing cork.
If petroleum oils were an attempt to generate a vapor barrier at the bore's surface, then the (petroleum) oil should impede the rapid intake of moisture. However, if moisture is present, wood will absorb it in spite of differing methods of wood treatment because wood is hydrophilic. If the wood is brittle enough and if dimensional changes are great enough from "breathing," the wood may crack.
This became the first premise of my hypothesis: petroleum bore oils simply do not protect against the dimensional changes from "breathing." Petroleum-based oils do not promote dimensional stability and (wood fiber) resilience. One could say that natural organic materials such as wood and cork do not "like" petroleum products.
Initial experiments with organic oil
When I began experiments on grenadilla instruments, I intuitively used organic vegetable oils. Also, I typically selected instruments in extremely poor condition.
One of my first experiments was on a very old, neglected, ring-system English horn with a severely warped upper joint and damaged bore. I prepared the wood and hand-oiled the body inside and out for three weeks. When the wood had saturated itself with vegetable oil, I wiped the body down and examined the instrument. I noted the bore had noticeably improved. However, I was very surprised to find that the warped upper joint was completely straight. Repairs on this English horn and other early instruments seemed to indicate that I was on the right track:
Organic vegetable oils interact with wood (fibers).
Organic oil can stress-relieve the wood even straighten a warped body!
Organic oil processing tightened loose tenon to socket fit, and improved key fit.
In dry climates, technicians typically must refit keys and tenon rings on new instruments. Because I didn't have the knowledge to save my original grenadilla clarinet, when I bought a new Buffet R13, I decided to oil it rather than do the usual refit.
I hand-oiled the bore, tenon shoulders and end grain for three weeks. At first, the wood absorbed vegetable oil so rapidly that I had to oil four times a day for two days. Ultimately, oiling frequency tapered off to once every three days. Once the wood had saturated itself with oil, I began break-in. Because of that initial oiling, I did not have to refit any keys or shrink rings for many years. I also noticed that the wood would sweat a little oil on its outside even though I did not oil the outside of the instrument These results indicated that:
Organic oils help maintain dimensional integrity.
Oil slowly diffused through instrument walls from the bore to the outside.
Thus far, my experiments had indicated that I could improve bore condition, improve tenon-to-socket fit, stress-relieve wooden bodies, and stabilize the dimensions of new instruments.
It appeared that vegetable bore oil was acting as a mediator between moisture and wood fibers. The presence of vegetable oils in the wood did not allow a rapid intake of condensation through the bore, but it was not acting as a vapor barrier either. The presence of vegetable bore oil in the wood still allowed the wood to absorb water vapor but at a greatly reduced rate.
Organic oil processing lessens dimensional changes when wood breathes.
Subsequent experiments using organic oils
An additional problem still existed. How can one increase the wood's resistance to cracking? The next series of experiments involved preparing several grenadilla clarinets for the University of Colorado's marching band. I conducted control group experiments by hand-oiling one group of clarinets and not the other. The clarinets treated with vegetable oil did not crack. However, several of the non-treated instruments did. These results reinforced the results of my earliest experiments, such as the one on the warped English horn. Tests to date indicated an increase in wood fiber resilience and a corresponding decrease in brittleness.
Vegetable oils interact with wood fibers to minimize or eliminate cracking.
Reports by NAPBIRT members using my vegetable bore oil formula verify most of the results of my original manual experiments. An unexpected result came from reports by these independent technicians that grenadilla wood absorbs more oil in humid climates than I had anticipated.
Oil processing improves scale and increases resonance even in humid climates.
For example, Pat Hyatt, a NAPBIRT member in Waynesville, Ohio, has been using my bore oil formula on clarinets since 1992. He has been very pleased and even excited about the results he consistently gets. Our frequent telephone conversations have been a bonus because of the reports he gives me from his customers. All reports have been very positive and typically include the observation that the instruments play "better than ever".
After hand oiling many, many instruments over a period of eight years, I decided to explore how I might improve the efficiency of oiling procedures. The next logical step was to develop an immersion processing system.
Initial immersion experiments
I began my immersion experiments from the thesis that total immersion of instruments should: (1) allow more uniform exposure of all wooden surfaces to the oil; (2) reduce the time needed (compared to hand oiling); and (3) allow greater control over the entire process. Also, I would have the opportunity to experiment with different procedural factors.
Results from early immersion experiments corroborated my hand-oiling experiments. As with hand-oiling, immersion processing improved socket to tenon fit, minimized key refitting, improved tuning to A440 with standard barrels, improved and stabilized scale, and (if properly maintained after immersion) eliminated the potential for cracking. Moreover, scale and resonance continue to improve and become "locked-in" during the instrument's three to four week "break-in" period following immersion.
Two different examples of improved tuning to A-440 involved both hand oiling and immersion processing. Shortly after moving to Denver, a new customer had me shorten his barrel 2-mm because his instrument had become flat. I showed him how to hand-oil his instrument. After nine months of regular hand oiling, the pitch of his instrument began to change. He now has to use tuning rings about 95% of the time with his short barrel.
Another customer had a "near new" Buffet extended-range bass clarinet that played very flat. The player stored this instrument for several years and rarely played or maintained it. The customer had recently joined a wind ensemble, and found that her instrument consistently played 10 cents flat. I corrected minor leaks and set all adjustments. I then mapped the scale of the instrument and found that over-all pitch was indeed 10 cents flat. I assumed that the condition of the wood was directly responsible for the over-all pitch problems. The customer agreed to immersion processing with new pads and key fitting as necessary. Once all work was completed, I mapped the scale again and found that the over-all pitch had risen 12 cents. The instrument could then be tuned to A440 with the mouthpiece slightly pulled.
Many customers have reported that after immersion processing, they no longer had moisture-tracking problems. If tracking problems do recur, oiling the bore, and several hours later, brushing and swabbing it clean can eliminate them. This procedure removes sediment track in the bore.
Vegetable bore oil eliminates the cause of moisture tracking.
With hand oiling, one does not note substantial improvement in the instrument's playing qualities for six to twelve months. After four weeks of immersion processing however, customers typically report an immediate improvement in scale, response, and resonance. These improvements continue to increase during the three to four weeks of "break-in." Because of the shorter time span using immersion processing, changes in physical and playing properties become much more obvious much more quickly.
Total immersion processing provides positive results more rapidly.
Later repairs on early immersion-processed instruments allowed me to observe their durability. If the customer periodically hand-oiled his instrument as necessary, I found that: (1) bore condition appeared to improve over time; (2) key and socket fit remained tight and stable; and (3) playing qualities of even scale, A440 tuning, and resonance remained artist quality. I also noticed that tone holes were clear with no chipping. None of the instruments had cracked. I now had the final premise of my hypothesis. With proper care and maintenance:
The stability of organically oiled instruments is long lasting.
Independent evaluation of immersion processing
As a result of clinics I had given at international NAPBIRT conventions, I have received instruments for immersion processing from technicians and customers around the country, from New York to California and from Alaska to Arizona. Comments from both the technicians and their customers are invaluable because they are not biased by direct contact with me.
Bill Boyer, a fine NAPBIRT technician in Bloomington, Indiana, initially sent me an instrument from Indiana University. This instrument had become "blown-out" or "played-out." The clarinet was in good mechanical condition and all pads were tight. However, the instrument was dead; it had lost its voice. I performed the immersion processing and Boyer performed all the finish work. An excerpt from Mr. Boyer's letter concerning this instrument was,
"I am writing to let you know how much the clarinet faculty at Indiana University liked the Buffet R-13 A clarinet we resuscitated' recently. Howard Klug, James Campbell and Eli Eban had decided to trade this instrument in on a new one, but I talked them into letting me send it to you for immersion. After you returned the instrument to me and I repadded it, all three of them played it and were pleased to accept it back into the School of Music's clarinet inventory." Boyer adds, "I am an oboist, so I prefer to let those pros do the testing and judging; but what struck me was how little key-refitting I had to do during the padding process."
I was quite surprised to receive this comment because I had not anticipated the possibility of resuscitating' blown-out instruments. This resuscitation subsequently occurred with two of Texas Tech Professor Bob Walzel's personal clarinets. I performed the immersion processing and Ernest Clark, another fine NAPBIRT technician in Lake Jackson, Texas, performed all the finish work. Professor Walzel's unsolicited comments include,
"...and thank you even more for the way my clarinet plays now! What an amazing turn around. I am playing that particular B-flat almost exclusively and just sent my A to Ernest Clark who will be sending it to you soon. I took both the B-flat that you treated and another newer R-13 I had been playing on my tour to Europe last Spring and everyone (not one exception) preferred the sound of the treated horn. This horn has always had a particularly sweet, beautiful sound, but now it once again has the evenness, resistance, and pitch scale that it had lost."
NAPBIRT members have echoed this preference for the "sound" of immersion processed instruments at two annual international conventions. A Buffet Crampon clinician, Joe Lukasik, and I presented clinics at these conventions.
The clinic, "Clarinets and Concepts," involved blind paired comparison tests between a new untreated R-13 and a new treated R-13, as well as my older treated R-13. The audience, composed of repair technicians as well as manufacturing representatives, preferred the sound, scale and apparent response of immersion treated clarinets two to one at the Denver convention and three to one at the Milwaukee convention.
Reports from traveling musicians during the last several years have provided another advantage with immersion processing. Musicians, such as Joe Lukasik, consistently report that they can travel from one climate to another without adverse effects on their instruments. Pad seal, key fit and scale integrity remain stable. They have indicated that if they travel from a dry to a humid climate, or from a cold to a warm climate, their instruments tend to sweat a little bore oil at the instruments' surface.
The best example I have of this latter phenomenon involves an oboist who did not "believe" in oiling. A long time customer of mine, he was hired as a guest soloist for a Midwestern orchestra. I performed a good playing condition on his instrument before he left Denver.
When he returned, he reported that his instrument completely failed within three days of arriving in Minneapolis. A repairman there loosened tight keys, tightened loose keys and replaced many pads. The engagement went well, but when the customer returned to Denver, the tightened keys bound, the loosened keys became too loose, and most pads leaked badly.
When the customer finally realized why I perform immersion processing, he agreed to immersion. I, of course, had to reverse all prior key fitting during the instrument's rebuilding. Since the immersion, this oboist has traveled to many cities around the country, and has not encountered any stability problems.
Lack of objective data
I have been unable to obtain any hard data concerning acoustic changes in immersion-processed instruments. I would like to know, for example, how the natural frequency of a grenadilla tube changes after immersion processing. Natural frequency tests are relatively easy to do because they involve measuring the frequency of a vibrating body.
Experiments using power frequency tests are more difficult but not impossible to perform. They would involve recording notes played on an instrument before and after immersion processing. The sounds would be analyzed on a frequency analyzer and compared. This provides a method of analyzing changes in frequencies after immersion. Unfortunately, these tests introduce a human variable. The player is required to play test notes for each session and each session may be separated by as much as six weeks.
I am well aware of the results obtained from using vegetable oils, but I have no hard data describing why and how vegetable oils interact with wood. Thus far, all attempts to arrange acoustic tests have failed, but I imagine that this situation will be rectified in the future.
Limits of organic oil processing
The saying, "You can't make a silk purse out of a sow's ear," definitely applies here. One cannot completely correct a poorly designed or poorly manufactured instrument, or successfully treat wood that is not well seasoned. If the initial condition of an instrument is poor, bore or tone hole modifications may marginally improve it. However, it may still elude the level of an "artist quality" instrument.
To my knowledge, I have never immersion-processed an instrument that has been re-bored. If a wooden instrument shrinks to the point that the owner has it re-bored, by definition, wood has been removed. While immersion processing can do many things, it cannot create new wood!
I have had only one grenadilla instrument that was completely unresponsive to immersion processing. It was a middle-line oboe made in the late 1940's. Its wood was extremely brittle and it, of course, had cracked. Crack pinning was difficult because the wood was greatly inclined to further chip and crack. I found that the wood, irrespective of the cleaning solvents used, would not accept any organic bore oil. The solvents I use to prep instruments before immersion should have removed all the usual petroleum products. The manufacturer had no idea how the wood had been processed; there was simply nothing that could be done to salvage this instrument. I suspect that something similar to a hot paraffin dip was used during or after manufacture. Sometimes a dead instrument will remain forever dead.
In this clinic, I have shared some of my experiences and some confirmations by other technicians and performers. At this time, I hope you might favorably consider the following conclusions I, myself, have reached:
Dimensional Change: Non-oiled grenadilla falls victim to dimensional changes in and the subsequent deterioration of the wood. "Breathing" is the instrument's automatic response to changes in temperature and the wood's moisture content. Regardless of degree of care, maintenance and bore treatment, wood will breathe. Our prime concern is to control the rate of "breathing." Dimensional changes caused by "breathing" affect instruments in many ways. Common problems include compromised key fit and pad seal.
Moisture and saliva damage: Deterioration of wood eventually occurs in response to damage caused by moisture and saliva. A compromised bore is evidence of this deterioration. Eventually, deteriorating wood becomes brittle. As brittleness increases, the probability of warping, cracking, checking, and (tone hole) chipping also increases; brittle wood cannot easily "breathe." In addition, brittle wood contributes significantly to changes in scale, pitch, and resonance.
Resilience: Organic (vegetable) oils do interact with wood, thus allowing the wood to become more resilient. A very large sample of cases indicates that oiling stress-relieves wood, allowing wood to return to manufactured dimensions and an original if not improved scale. Oiling new instruments will stabilize them, avoiding typical key and ring re-fitting procedures. Oiling stabilizes the integrity of wood over time.
Manual versus systematic oiling: Although hand-oiling greatly improves an instrument, immersion processing brings about these changes more rapidly. Immersion processing allows the player to notice more readily any improvements in the playing qualities of his instrument. These improvements include a stabilized even scale, A-440 tuning, and a noticeable increase in resonance.
Petroleum versus organic products: I have never observed positive results on cork or wood treated with petroleum-based products. Petroleum products neither arrest nor reverse wood (or wood product) deterioration. If a new customer brings me an instrument with wood in poor condition, I know that they have not used vegetable bore oil, but I don't know if they were using petroleum bore oil. I have never received any negative reports from customers or repair technicians from around the country who have used my vegetable bore oil.
We all need to protect our valued instruments against deterioration and, if possible, to improve playing quality. I believe using organic products on cork and wood does both. To date, I have not received any responses to my 1991 challenge to NAPBIRT members: provide me with testable information that disproves the results of organic vegetable oil processing. Respectfully, I offer you the same challenge!
It would be my pleasure to share my handouts with you. For those handouts or other information, or to discuss any information I have presented at ClarinetFest'97, please contact me at:
Naylor's Custom Wind Repair
6726 South Dahlia Court
Englewood, Colorado 80113, USA
In my repair practice, I routinely provide care and maintenance handouts to my customers as well as offering for sale, organic vegetable bore oil and oiling accessories, and immersion-processing service. The following table has proved most helpful to technicians and performers:
Table 1 RULE OF THUMB Diagnosis and Treatment
(yes, I have taken readings as low as 1% indoors!)
In addition to this table, it would be my pleasure to share my handouts with you. For those handouts or other information, or to discuss any information I have presented at ClarinetFest'97, please contact me at:
Naylor's Custom Wind Repair
6726 South Dahlia Court
Englewood, Colorado 80113 USA
I presented many examples of instrument problems during the clinics that were not included in the above handout. The most important example was the following:
David brought his clarinet to me several weeks before ClarinetFest 97 and told me the following story. The clarinet was a Pete Fountain model Leblanc that he used for the past 32 years. His "old Friend" went through college, the Army band, and many years of professional performances with him. However, for the proceeding several months the scale and relative pitch of the clarinet had become uneven. His friends suggested that he take the instrument to me for an immersion rebuild, but fortunately, he sent it to Leblanc instead. Tom Ridenouer determined that the clarinet was in good mechanical condition and that all pads were sealing. He compared the bore and tone hole measurements to factory specifications, but he could find nothing wrong; all measurements were within factory specifications, yet the instrument's scale was obviously deteriorating. Both he and the customer service manager, David Surber, then suggested he send the clarinet to me for immersion treatment. Once I completed all work, David's "old friend" returned to good health and has been stable ever since. David said that his clarinet might be playing better than it ever had.
This example draws attention to several factors. First, even with good care over many years, a fine instrument's scale and relative pitch can change enough to render the performance qualities of the instrument unacceptable. Second, these changes are often so slight that they are not measurable, yet we know they occur because the instrument consistently begins to play poorly. Third, a third party made all comparative measurements and they were independent of my influence. Last, historically people believed that a deteriorating, "blown out" instrument could not be salvaged, but we now know that this belief is no longer true.