As wood ages, it dries and hardens. Exotic hardwood (ABW, Cocuswood, Ebony, etc.) become very hard over time and their resonance improves, supporting the assertion that older bagpipe produce superior tone. The trade-off here is that they also become somewhat intolerant of rapid changes to either temperature or humidity.
Temperatures and humidity are more stable in the UK than elsewhere around the globe and instances of drones cracking are much less frequent than in North America and elsewhere around the globe. Because of this, we should be more aware of the circumstances that might lead to a drone cracking and take preventative measures.
I think that it’s important to understand and appreciate that bagpipers are a small minority within a much larger family of woodwind musicians. We have kept pretty much to ourselves over the years. Very little information has been exchanged on the instruments themselves or on their care and maintenance.
All woodwind instruments are subject to moisture appearing on bores. This is mainly caused by moisture within our breath condensing on the cooler surfaces of the bores. Weather conditions and our own personal blowing characteristics are also factors. When condensation occurs or liquid is otherwise brought into contact with the bores, a certain amount may be absorbed by the wood, causing it swell. If moisture is brought into contact with the inside bores, this will cause the wood to swell creating stress along the outside surfaces. If the rate of expansion on the outside cannot keep pace with the rate of expansion on the inside a crack will occur.
By the same token, as this liquid evaporates, it abandons cavities within the wood, causing shrinkage. Over time, this constant expansion and contraction can impose “micro-fractures” within the walls of the drones, diminishing its abilities to withstand future movement. At their very worst, these stresses manifest as warps or cracks.
Rapid changes in temperature also has an impact on the stability of the wood. Dramatic changes in temperature will cause the wood to expand and to contract, which contributes to the weakening of the wood structure.
As mentioned above, much of the water that we see collected on the inside of the bores of bagpipes has been deposited there by moisture contained in our breath. That moisture contains many of the same properties (enzymes) contained with our saliva. These properties help us to break down organic material for digestion purposes. Simply stated, woodwind instruments are made of organic material. Any moisture containing digestive properties that is deposited within a woodwind instrument is potentially destructive. Over time these enzymes will have a negative impact on the wood and on the natural oils contained within.
Exotic hardwoods are incredibly dense. ABW, as an example, contains a thick tar-like pitch within its cellular structure. If you were to take a piece of Blackwood and place it in a frying pan over moderate heat, you will witness this pitch bubbling to the surface. This pitch and its protective properties are probably the main reason why ABW gained favor with makers, especially when shipping bagpipes abroad. Exposed to those conditions mentioned above, this pitch can break down over time and leave the wood unprotected and vulnerable.
Of course, also within exotic hardwood is water. Over time, water evaporates causing shrinkage. As water (or any liquid) is returned to the wood, it will absorb a certain amount, swelling the wood. When this occurs on the inside bore of a musical instrument, the expansion is often rapid causing stress to build up on the opposing outside surface. When the resultant expansion that must occur on the outside surface cannot keep pace with the expansion on the inside surface, cracks develop to relieve the stress. Sometimes these cracks are confined to the surface. Sometimes they extend to the inner bore.
The best defence is to maintain the oil/water content within the blackwood at a constant level. This means keeping the natural oils and water in, and keeping moisture containing digestive properties out. Considering that the wood will always be expanding and contracting slightly due to changes in temperature, the application of a proper natural bore oil is critical to protecting the internal properties and vitality of the wood.
The first line of defense is to swab out the bores after every playing!
Whew! That was exhausting!
Now we can begin the debate on the next controversial subject; “What kind of oil is best?”
For an oil to be effective it must be absorbed into the wood. Let me step back slightly. For an oil to be effective it must be absorbed into the wood at the “right” rate of absorption. If the oil is absorbed too quickly the wood will expand quickly creating stresses on the opposing surface. Unless you’re applying oil to the “naked” outside surface, you might be risking a split or crack.
When I’m doing restoration work, I remove any finish on the bagpipe and apply oil to the outside surface first. I allow the oil to penetrate from the outside surface. I apply several light applications over several days. By approaching the most vulnerable part (outside surfaces) first I minimize the risk of stress created later when I’ll oil the inside bore.
If I’m working with a bagpipe made from ebony, I prefer to leave the outside surface as is, so that oil may be applied from time-to-time on the outside surface. With ABW or cocuswood, after I’m satisfied that the oil has penetrated sufficiently I may or may not apply a shellac finish.
Most commercial bore oils are mineral based. These contain solvents and distillates that aid in the absorption properties of the finished product. These oils do not oxidize or go rancid. The product is very consistent and the viscosity can be adjusted for a wide range of applications. Mineral oils are also relatively inexpensive. Scientific research has shown that many of these processed mineral oils also contain contaminants that clog the pores of the wood.
Researchers agree that natural plant oils are best. Among this group you will find teak oil, canola (rapeseed) oil, almond oil and a host of other common and exotic oils. In order for a natural plant oil to be effective, it must be blended with antioxidants and stabilizers to preserve and enhance their best qualities.
So how often should you oil?
Haven’t had enough, eh? Here’s what I say. You may find those who agree and disagree.
If you own an older bagpipe and have never oiled it, be very cautious. I would be inclined to strip the outside finish off the bagpipe apply oil to the outside surfaces first. You may or may not want to re-apply a shellac finish.
With a new set of pipes, I would oil them upon receipt and thereafter according to the climate.
If you live in a hot, dry climate, oil more frequently. If you live in a cooler, more temperate climate, oil once or twice each year.
However frequently you choose to oil, be sure to remove any excess oil remaining on the wood. What is not absorbed into the wood should be removed. Do not allow oil to stay on the surface of the wood.
My research has led me to Omar Henderson, a.k.a. The Bore Doctor. The Doctor holds a PhD in chemistry and has researched this topic for many years. The result is a bore oil product that nurtures and protects the wood without clogging the pores or otherwise leaving negative footprints. The Bore Doctor’s Wood Preservative is carefully blended and balanced to provide the utmost care and protection for all exotic hardwoods. There is a tremendous read on The Clarinet BBoard on the topic of oiling exotic hardwoods.
