The Clarinet BBoard

The Clarinet BBoard The C4 standard

New Topic | Go to Top | Go to Topic | Search | Help/Rules | Smileys/Notes | Log In

Previous Message | Next Message

Re: Henri Chedeville mouthpiece question

Author: L. Omar Henderson
Date: 2010-12-25 06:10

After the WWII the rubber industry became more efficient due to the needs of the war effort but mouthpieces were forever changed because they are now molded and not machined out of a vulcanized rubber rod stock. Molding also necessitates a different rubber formulation and curing process than making rod stock. Modern rubber formulations include both sulfur and other catalytic enhancers for the crosslinking that forms vulcanized hard rubber, whereas only sulfur and an organic agent were used in making rod stock..

In rod stock there are, or were, various curing stages that formed a more homogeneous rubber than molded pieces that undergo differential cooling because their thicker and thinner parts of the mouthpiece. Another overlooked difference in vulcanized rubber today is that in the 1920's - 40's the raw latex was much less purified and contained a number of contaminants like plant debris which alter the pattern of crosslinking in the finished rubber. The sources of the raw latex changed too from native rubber trees to hybrid rubber tree plantations and the major production areas and climate migrated from the India regions to Indonesia.

Recreating the rod rubber produced in the 20's & 30's is a challenge since scant records of production methods and techniques survive. The process is experimental to emulate the conditions used to produce the rod rubber but includes using the highest quality latex (there are several commercial grades available) while simulating potential elements that alter crosslinking patterns and then recreating the amount of sulfur used as catalyst, the coloring agents, the time, temperature and pressure of the vulcanization process and then the heat curing schedules.

Modern rubber manufacture has helped with machines and techniques to measure the hardness, flexibility, and crosslinking pattern of the rubber samples. Acoustic properties are probably the hardest parameter to assess. After many expensive trials and testing we finally developed a method of testing and optimizing the acoustic properties of the rod rubber, and with other measures to develop quality control parameters for batches.

There are few companies that still produce rod rubber stock using the antiquated methods but this approach is the only way to recreate rubber of the same characteristics as the old Chedeville blanks.

The material is only part of the equation of making mouthpiece blanks but that is a discussion better left to the mouthpiece making artisans.
L. Omar Henderson
www.doctorsprod.com

Reply To Message | Avail. Forums | Flat View

Newer Topic | Older Topic

Topics