A wooden flute does not need a lot of maintenance. A few golden rules and some care will normally guarantee you years of pleasure. In this section, first general maintenance rules are explained, followed by a list of some common problems.
How to avoid cracks
Keep your flute dry, but not too dry. When wood adsorbs moisture, it swells, and when it dries, it shrinks. This well known fact is at the heart of quite some problems.
There are two ways in which cracks generally develop. The first is that the instrument is not taken apart and dried after it has been played. Water can then build up in the cavity in the barrel. The tenon of the flute body will swell, notably on a place where the wood of the barrel is rather thin. A crack will be the result.
Secondly, when a flute is played regularly, but is kept in a very dry room, the outer part of the wood will dry out and will start shrinking. The inner part stays humid because the instrument is played regularly. The wood will have no choice but to develop surface cracks.
- Take the instrument apart, especially head and body, and dry it after playing
- Oil the instrument regularly, this limits water absorption
- Keep your instrument in a room with an air humidity of at least 50%.
- Do not close the tuning slide completely when you put the instrument away
How to dry the flute
First take the flute apart. To dry the flute, use a normal flute cleaner, preferably a wooden one with chamois-leather. To clean the head, fix a piece of chamois-leather onto a stick with a diametre of about 15 mm (you can buy this in a DIY-shop).
How to oil the flute
The main purpose of oiling the flute is to refrain the moisture from entering the wood. Regularly oiling the instrument will also prevent saliva from attacking the wood and this will keep the bore polished. Both unboiled linseed oil and almond oil are suitable. I prefer almond oil, mainly for the smell.
The idea of oiling is to apply a small amount of oil regularly. When you have a new instrument, during the first two months you should oil it once every week, then once a month for the rest of the first year, after that about 2-3 times a year. Apply the oil when the instrument is dry, before playing. In order to avoid using too much oil, I dip a wooden stick into the oil, and then twist the stick around in the bore. When you see a thin film of oil evenly spread all over the bore, it is ok. It might be necessary to repeat this action two or three times. Don’t forget the head joint if it is not metal lined, and also put some oil on the embouchuse hole. The outside of the instrument does not really need oil; I use some of the spill, if any, to spread it out on the outside.
In the case of a keyed instrument, you can put small pieces of plastic under the pads in order to prevent the leather pads from coming into contact with oil. Oil coming onto a pad would ruin it.
What to do when I discover a crack in my flute?
When you discover a crack, you will have to go to and see a professional. In the meantime check at least whether the humidity in the place where the flute is kept is ok. Stop playing the flute, and certainly don’t oil it. If you have no chance to go and see a professional immediately, and if the crack develops further, you can decide to put a very liquid ‘super glue’ (cyano-acrylate) in the crack. The glue must be fluid as water, if not, you'd better do nothing. The fluid glue will be sucked into even the finest cracks in the wood, and helps to stabilise it.
Although the saying that ‘there are two types of flutes, flutes that have cracks and flutes that still have to crack’ is largely exaggerated, the bad news is that cracks are never to be excluded, even when using well seasoned timber. The good news is that cracks can be repaired rather easily, and if this is done professionally it will be hardly visible afterwards.
What to do if the corks come loose?
After a while, cork looses its elasticity, and also the wood itself might shrink to some extent. Before replacing the cork, you can put some linen thread on top of the cork, to readjust the fit. The cork will prevent the thread from turning, which will cause problems if you use thread only. First put some paraffin (candle) on th thread, followed by cork grease. This solution will at least last until you decide to replace the cork or let it be replaced.
What if the rings come loose?
When the wood shrinks, even to a small extent, the metal rings can come loose, because they of course don’t shrink. It is important to fix loose rings, not only to prevent them from getting lost, but mainly because a loose ring will not give the mechanical support to the wood to help to avoid splits, especially at the tenons.
If you can take off the ring, clean the inside with coarse sandpaper or with a round file. Also roughen the wood with a file or sandpaper. Glue the ring back in place with a 2-component epoxy glue, this is one of the only glues that can fill gaps really well. Clean the spilled glue with acetone before the glue dries up.
If the ring turns but you cannot take it off, the best thing to do is to buy a very liquid type of ‘super glue’ (cyano-acrylate), and to let some glue penetrate the opening between the loose ring and the wood. Dip a needle into the glue; when you put the needle exactly in the cavity between ring and wood, the small drop of glue will be sucked in the gap. After some dips, the cavity will be filled and the ring fixed. The whole operation takes just a few minutes, and can be repeated at wish.
What if the tuning slide’s movement is obstructed or if it is too loose?
If some dirt has come onto the tuning slide, or if the flute has not been played for a while, the movement of the tuning slide can become difficult or even get completely blocked.
In the first case, take the tuning slide apart and clean it completely (the ‘male’ as well as the ‘female’ part) with a clothe dipped in some kind of solvent (acetone, white spirit,...). Then put new grease onto it (I like the grease from the brand 'Tromba', it is a perfect grease for corks as well as for the tuning slide). If nothing has been damaged, the tuning slide should work again smoothly.
If the tuning slide is blocked, the best way to try to get the pieces loose is by man power. It is much easier to ‘unblock’ the tuning slide by pushing if further in, than by pulling it out. That’s why it is best to put the flute away with the tuning slide partly open, especially if the flute will not be used for quite some time. Avoid using tools. Only tools specially made for this purpose will do a good job, others in general won’t help or can damage the instrument. If using the force doesn’t work, you’ll have to go to a professional.
A tuning slide can also become too loose; especially on old and often used instruments. In this case you'll have to see a professional. In a workshop it is not difficult to widen the ‘male’ part slightly to get a better fit.
What if the keys seem to be leaky?
First check which key(s) cause the problem. Close one end of the flute body with a cork, close the finger holes and blow and suck. If there is no problem with the keywork, no air should come in or out. If this is not the case, push each key closed in turns, or ask a second person to do so, untill you have determined the bad ones.
The leaking can be caused by two things. One of the reasons that pads are leaking is the fact that pads loose elasticity when they get older, and hence don’t close the hole perfectly anymore.
The second reason can be that the free movement of the key is obstructed.
Control whether the key still moves freely and reacts immediately when you try to use it. If all keys move freely, it will be necessary to change the pads, a normal operation after a couple of years. While waiting for a chance to visit a professional, you can close the key with an elastic band or by putting some wax in the hole.
If they do not move freely, and you have pin-mounted keys, unscrew the axle and put some oil on it, then put it back into place. If nothing more serious is wrong, this should help.
If you have block-mounted keys, first try to put a drop of oil between the wood and the key. This might be enough to cure the problem. More likely, it will be necessary to widen the block opening slightly. Given the precision needed, this should be done by a professional.