With traditional tenons, the tenon is somewhat tapered at the beginning. The cork lies in a deeper groove and is relatively thick. Cork is a very good moisture-resistant material that can be compressed and can, therefore, give the necessary hold. The taper is used to allow easier assembling of the different joints. For school instruments, traditional cork tenons are certainly an appropriate solution. However, better alternatives should be considered for high-quality instruments, as traditional ones can pose the following problems. improved tenons
This traditional tenons can cause the following problems:
1. The joints can get stuck and hard to assemble
Since the tenons are always exposed to high humidity, it can quickly happen that the diameter at the end of the tenon expands. This is a common problem, which can be observed above all with new instruments. It is then difficult to collect or disassemble the instrument parts.
The reason for this is that the new body parts were turned to size when dry. As soon as they have been exposed to moisture, the wood swells and the tenon expands. On the receiving side will be a metal ring preventing the wood to expand and the tenon from the top-joint will not go all the way into the receiver. You can find helpful information under More information
2. Tenon wobbles
A. The tenon may become loose over time.
B. This can cause some leaks at the instruments tenon,
C. the body parts can twist,
D. The correspondence of the keys, which have a connection to the upper part, becomes uncertain,
E. the instrument loses resonance
F. and it can even fall apart if the wood becomes too dry and shrinks.
G. A tapered tenon connection will always need to be pushed in all the way. It is not possible to pull it out since it would cause the joints to wobble
Instead of natural cork, pressed or artificial cork is now used for cost reasons. It is harder and harder to work with, but otherwise has similar properties to natural cork.