The pictures to the right show the crack repair on a R13 where the crack runs through the tone hole. By inserting a new tone hole plug a perfect seal can be achieved even if the crack continues to move.
Article 1 - How to look after a wooden clarinet or oboe
Article 2 - Cracks can be repaired
How to care for your wooden clarinet or oboe
Grenadilla is a hardwood of the rosewood family. It is a very dense wood that when green, will sink in water. The wood immediately below the bark is white and it is the heartwood that is almost black. To prevent wood from cracking, makers take great pains to season the wood. Seasoning is the process that reduces the moisture content in the wood. Wood is like a sponge in that the cells of the wood can or cannot be full of water. The size of the wood doesn't change (like a sponge) when the water is squeezed out. Wood is at it's most fragile point when the water has been squeezed out of the cells leaving the cell walls still damp. The wood begins to shrink when the water leaves the cell walls. The wood gains strength when all the water is gone. This process takes years.
When the wood is at zero moisture content, it is not a stable condition and under normal conditions will absorb some water. A balance is achieved when the wood is no longer gaining or losing moisture. Grenadilla is a dense wood and water travels in and out very slowly. This demands a very long drying time to become stable. In finished instruments where the wood has been seasoned well, the incidence of cracking is lower. If the wood has been seasoned/dried properly the wood is more stable and theoretically won't crack but unfortunately wood is a product of nature. In a perfect world the wood can be controlled as long as it is seasoned/aged properly. Some manufacturers do 'accelerated' seasoning.
If you play your wooden instrument for long periods of time without swabbing you are challenging the wood to absorb water. If you play your instrument in a cold room you are challenging the wood to expand on the inside when the outside is cold and doesn't want to expand. If you blow warm, moist air into your cold instrument there is a possibility that the bore will expand so much that the clarinet will crack. You want as little difference as possible between the inside temperature of your instrument and the outside. Playing in a cold room also increases the amount of condensation and again the instrument will get so wet so fast that there is a possibility that the bore will expand and the instrument will crack. These two situations are where you have 'some' control
Some say that if you humidify your instrument inside the case you will equalize the moisture from playing. This makes sense. It all depends on what stage of seasoning the wood is at. If the wood has reached the point where it is no longer gaining or losing moisture it shouldn't make any difference. If the wood is too dry it should help. There is no magic formula. I don't think you will do any damage. The solution is to equalize the humidity inside and outside the instrument. The amount of moisture that is in the fresh peel of an orange is all you need. Simply put fresh orange peels inside your case side compartment (NOT inside the bore of the clarinet) when you put it away to humidify the clarinet. Replace the peals everyday. You have to eat an orange everyday and this is also good! There are commercially made humidifiers available for just this purpose as well.
At the end of the day it is all a bit of a guessing game. Each manufacturer has there own 'optimum' way of preparing their wood for instruments. In addition to what I have said above, every piece of wood has a 'personality' of it's own and that is more of an unknown than anything. What I know is that wood tends to crack in cold, dry weather. One last thing. Don't ever use bore oil your instrument. Leave the decision to oil or not to oil to your technician. You can ruin your instrument by oiling it. If you can tell that an instrument has been oiled, it means that it has been over oiled.
The shape of the bore is critical for proper intonation. Any change of shape due to swelling or wear makes a difference. When we say a clarinet is 'blown out' or worn out it means that the bore of the instrument has changed shape from playing (getting wet) and swabbing. It becomes more difficult to play in tune and it loses much of it's resistance. A 'blown out' instrument will play consistently sharper and sharper. If that instrument is left to sit for a period of time the bore will shrink but will open up again once you re-begin playing it. Sadly, clarinets/oboes wear out. There are some things you can do to slow down the process. When you dry your clarinet, leave it assembled, turn it over and drop the swab through from the bottom to the top. Pull slowly and don't use a swab that is too tight-fitting. You need to reduce wear on the bore, and swabbing it in one piece prevents wear at the openings of each tenon. Also, swab often while you're playing, as you don't want the wood to get too wet. You want the wood to absorb as little water as possible. Again, think of equalizing the moisture inside/outside.
If your clarinet cracks, don't panic - we can fix it
Sometimes no matter what precautions you take, your clarinet or oboe stills cracks. Although it would be nice if this didn't happen, we can repair the crack and the instrument will be good as new.
Every wooden instrument has it's own characteristics based on the particular piece of wood. No two wooden oboes/clarinets sound exactly the same. If you have carefully chosen your new instrument, you won’t want to have to replace a part of it because it cracked - it won’t be the same instrument. Some say that the instruments that sound the best are actually made from an unstable piece of wood, and that is why they crack. Who knows, but the force created by cracking wood is one to be reckoned with.
Before we repair the crack we let the instrument stabilize in the proper environment ... in other words, the ideal playing situation. Sometimes we will humidify the instrument if it seems to be very dry. Often, but not always, the crack will close up. Whether it does or not, after the instruments has 'stabilized' we can repair the crack.
We used to pin cracks to keep them closed, which was moderately successful. Often the addition of the pin could change the characteristic sound of the instrument. There were also times that not even a pin could hold the crack closed. Now days there are some wonderful glues available and, mixed with granadilla wood dust or carbon fibre, they work very well.
Cracks don’t necessarily run through to the bore and more often than not you cannot see the crack when you look down inside the bore. When the crack runs through a tone hole it is more serious, as often the crack will open and close many times over the life of the instrument. If the crack does go through the tone hole, we have to replace the top surface (going nowhere near the undercut) of the tone hole. Then, if the crack opens, the pad wont leak (see pictures above.) The repair of the crack is successful if, in the end, the clarinet has a good seal, as a good seal is critical to the playability of the instrument. With a bit of luck the instrument won't crack again, as this usually happens when the instrument is newer rather than older.
Some say that you should gradually 'play in' an instrument. In other words, begin by playing only a few minutes the first day and gradually increase playing time until you are playing as long as you want to. The theory behind this is that you are allowing the wood to equalize the moisture inside and out. Sometime this works and sometimes the instrument cracks anyway. The important thing is to realize the precautions you need to take with your new wooden instrument and to hope for the best.
