Flutists invest money, time, and love, in their instruments. To keep a Baroque flute in good shape and able to play its best, there are things you can do to help preserve its quality.
Wood is a very resilient material. It can last for hundreds of years and be beautiful and useful during that whole time. It is also a reactive material that changes with the climate and usage it experiences. It is possible to quickly destroy a flute or use it for a lifetime. The most critical element is humidity. A flute reacts to changes in humidity throughout the year and responds to the climate within a house as well. In addition to this basic state, when a flute is played, it is suddenly being exposed, especially on the interior, to air at virtually 100% humidity. It should also be noted that different woods react more to these changes than others. For instance, ebony might be quick to crack, while boxwood is more likely to warp. A wood like coccus, used in many 19th century flutes, is more stable than ebony or boxwood, which is one of the reasons it was so widely adopted.
In my house in Ohio, the humidity throughout the year goes from roughly 65% down to 25% in the winter. The outside humidity is made worse by forced air heating. For the most part, high humidity does not create problems although in extreme circumstances it can foster the growth of mold. Additionally, if you have a boxwood flute, for example, that has been quite dry for a long period, and you suddenly expose it to high humidity, it could warp.
However, the real problems are created by low humidity, which for those living in the northern half of the US, is quite low in the winter. Allowing the wood to get too dry makes cracking more likely, and this is even more likely when a player suddenly blows warm, wet air into the flute.
A Good Humidity Level
For many years I was the instrument curator for a major music school with 250 Steinway pianos and thousands of other valuable instruments. We used the standard of 42% humidity that is recommended by Steinway. I think this is a good minimum, but for my own collection I am usually at 50-55%. In past years, before I had really cured my dry air problem, I would have at least two to three antique flutes crack each winter. Often these cracks were re-openings of old repaired wounds. This year, I had a modern ebony Baroque flute crack in the midst of a long rehearsal day in a fairly cold church. It was too dry and cool in the church compared to my warm, wet, wind. Sometimes, this just happens.
Getting an entire house to this sort of high humidity is virtually impossible during the heating season. There are a number of possible solutions. Some people close off a smaller room and use one or two humidification units. Minimizing the temperature – within reason – in the room also helps. If you have a small number of instruments to worry about, you can make an enclosure and keep it at a higher humidity. One successful method for a small enclosed space is to use humidity packages. These are actually designed for keeping cigars (or guitars) at a constant and appropriate humidity, but they work well for flutes too. This is better than using a dampit or wet sponge of some type in your case.
One solution which I had hoped would work – but doesn’t – is a whole house humidification system attached to the furnace. Companies offer inexpensive ones that just squirt some mist into the out-going air as well as much more costly models that involve the creation of lots of steam into the output of the furnace. I tried the cheap method, and it basically did nothing in my house. I then bought an expensive steam unit which raised the humidity by about 4%, but it was still under 30%. These might make the house more comfortable for people, but they are not going to help wooden flutes. My final arrangement, which works extremely well, was to take a small closet and install a humidifier in the bottom. I cut 1.5-inch holes in the shelves that divide up the closet, to allow the humidity to move around. This has given me a very steady humidity at my goal percentage of 50-55%. I realize this is overkill for most Baroque flute players, but it is a good way to store any wooden instrument.
I have never had the problem myself, but I know of others who have. Once you get mold, it is extremely hard to really kill it off, so that it does not reappear. This can affect all types of wind instruments. I often see people storing flutes in plastic boxes with the idea that it will keep the humidity steady. It will do that, but it also makes it possible for mold to grow. You want some air circulation as well as humidity, so be careful if you use those boxes. I do use them in my collection, but generally not with flutes that are in regular use.
Getting rid of mold is difficult. I have talked quite a bit about this issue with one of my flute restorers, Jon Cornia, and he has come up with a solution of thoroughly cleaning the instrument with a medical-grade disinfectant called Fiberlock ShockWave, used diluted. This is strong stuff and should be used carefully. When the flute has dried, oil it right away.
The joints of Baroque flutes are a particularly sensitive area. If a joint is too loose, air will leak, and the flute will not work properly. If a joint is too tight you risk cracking the socket. This sort of crack can cause long-term problems as it takes very skilled repair work to keep the crack closed. These days, Baroque flutes have either cork or string joints. String joints are what would have been used originally and are less likely to crack the flute. Cork joints were introduced in the 19th century once sockets became metal lined. Be sensitive to how tight your joints are. If they are loose, just add some new string. The best way to prepare the string is to pull it through a block of bee’s wax. This will allow the string to stick together and stay in one place on the flute. People use many different types of thread – cotton, hemp, sink, and synthetic. It is best to use a string that is not so likely to shrink.
New flutes, or flutes that have not been played for a long time, should be carefully broken in. The purpose of this exercise is to help the wood adjust to the right moisture level. When I get a new flute, either modern or antique, I really want to play on it. It takes some discipline to control the time I spend playing the instrument. I think the most important period is the first two weeks. Playing the flute two or three times a day with a good break in between, is ideal. I think the flute adjusts more quickly this way than with just once a day. The first two days spend maybe 15 minutes per session. Then add five minutes per session each day. Keeping the instrument in well-humidified air is especially important during this time.
As the joints are one of the most often damaged parts of the flute, it is important to store the instrument disassembled. This lessens the chance of the tenon or socket warping. Always swab excess moisture before storing. It is fine if it retains some extra moisture – just not drops of fluid. Do not leave your instrument out in the sun as this changes the color of the wood. Don’t leave your flute anywhere you might sit on it. This may seem obvious, but I have seen it happen to a number of people.
I have saved oiling for last, but it is one of the most important proactive things you can do to protect your Baroque flute or recorder. When someone asks on social media, “How do you oil a Baroque flute,” there are generally 50 answers and a good bit of disagreement. Following the advice of your instrument maker is always a good idea. They know the wood and how it was prepared. My main Baroque flute maker, Marten Wenner, uses a mixture of three parts almond oil to one-part orange essential oil. These should be top-grade, organic, natural products. The orange oil helps keep the almond oil from growing rancid, makes a nice smell, and adds to the cleaning properties of the oil. I have experimented some with other types of natural essential oils, but orange is a good safe choice. Some makers and player recommend Linseed oil, and 40 years ago this was the standard. In recent years, however, people have shied away from it as it tends to build up like a varnish on the surface of the wood.
My rule of thumb is to oil a flute at least at each season change. The most important time being the start and end of winter. In practice, it depends on how much you are using a flute. If you play it every day, you may well want to oil it more often. If you sense the wood is getting dry, it is time to oil it.
To oil, I suggest using a swab stick with a small piece of cloth that does not put off a lot of lint. I often use two different pieces of cloth, one smaller for the RH and foot joint, and a bigger piece for the head and LH joint. It is easy to get the swab stuck in the RH joint if the cloth is too big. On the other hand, if it is too small, you will not have enough contact in the head. I dip about 1/3 of the cloth in the oil and shake off the excess, then swab out the interior of the flute. Some people believe it is necessary to remove the cork. I don’t do that, and generally unless you really know what you are doing, you might not end up with the cork back in the same position.
With a 1-key flute, you want to avoid getting oil on the pad or in the mechanism of the key. It is a good idea to put plastic wrap under the key to protect the pad. You should put on enough oil that it is very clear that all surfaces have oil on them, but it should not be dripping oil. Next, I would oil and lightly buff the exterior surface. A flute can get pretty dirty, and this works as cleaning as well as oiling. It is also a good idea to take a Q-tip with a small amount of oil and run it around the interior of the embouchure and tone holes.
Once a flute has been well oiled, let the parts sit vertically to allow any excess to drip out. I usually leave the flute siting for four to six hours, allowing the oil to soak in. What you see after those four hours is important. Some flutes will soak up every bit of oil and look dry again, while others will still look wet with oil. The ones that look dry should be oiled more often. The ones that remain very wet may have a finish on the wood that prevents the oil from being absorbed. In either case, use a dry, clean cloth to remove any excess. When done, a good bore will look shiny but not really wet. Use a dry Q-tip to remove any excess oil from the embouchure and tone holes.
I normally let a flute sit for at least four hours after playing before I oil it, and I would wait an hour or so before playing it after oiling. Your flute should now feel very happy. It should look, feel, and smell better. A wooden flute really can last a lifetime if properly cared for.