Care of the Wood - Oiling
I recently spent considerable time to research this topic. Although I very much support the concept and practice of oiling bagpipes, I had never heard or seen scientific data to confirm my beliefs. It is interesting to learn how others throughout the greater "woodwind instrument" community address the subject.
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.
Throughout the greater woodwind community, as throughout our own bagpipe community, African Blackwood is king. This is not to say that other woods aren't recognized and favoured by some however suffice to say that African Blackwood is used extensively and valued most highly.
So, at least for the purposes of this topic, we have two common links (a) woodwind (b) African Blackwood.
We know that 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 also contribute.
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. As this liquid evaporates, it abandons cavities within the wood, causing shrinkage. Over time, this constant expansion and contraction can impose subtle and greater stresses throughout the instrument. At their very worst, these stresses manifest as warps or cracks. This paper will address why this is so and what you can do to combat these assailants.
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 contained with our saliva. These properties help us to break down organic material for digestion purposes. Simply stated, African Blackwood and its internal properties are organic. Any moisture containing digestive properties that is deposited on African Blackwood is destructive. Over time these enzymes will have a negative affect on the wood and on the natural oils contained within.
African Blackwood is incredibly dense. Within it is a thick tar-like pitch. 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. Exposed to those conditions mentioned above, this pitch can break down over time and leave the wood unprotected and vulnerable.
Of course, also within Blackwood 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 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 proper bore oil is critical to protecting the internal properties and vitality of the wood.
The first line of defence 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 for a few days. By approaching the most vulnerable part (outside surfaces) first you will minimize stress created later when the inside bore starts to respond to oiling. I then fully submerge the piece into an oil bath without risking stress-related splits.
It is hardly practical to strip off the finish every time you want to oil your pipes. This is why it's better to oil your pipes regularly once of twice each year. You will be addressing minimal loss of oil and water with minimal absorption of bore oil resulting in minimal stress. Makes sense!
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 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 I 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 and submerge the pieces in a complete bath for about a week. After a thorough clean up and a proper protective finish on the outside I would oil the pipes according to the climate I play in.
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 to thicken and create other problems.
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 Wood Preservative is carefully blended and balanced to provide the utmost care and protection for all exotic hardwoods. He has prepared a detailed manuscript on oiling African Blackwood with photomicrographs and other compelling supportive documentation. I will be referencing that manuscript on The Bagpipe Place once it has been published.
Good luck and good maintenance!