Relative Humidity and Bracing
Most people may be familiar with the importance of a controlled climate in a luthier workshop. The picture shows the impact of low relative humidity on an instrument that was built for a different climate. The prairie winters here in Winnipeg are extremely dry, and for that reason I do all crucial glueing between 30 and 35 % r.H.. Depending on the local climate, luthiers pick an artificial climate that keeps their instruments safe against drying damage. For example, in Germany those values are between 40 and 50 % r.H.. It is obvious that it could be problematic importing an instrument built under such conditions into our dry prairie climate. The reverse is much less dramatic. A “dry-built” instrument may not sound its best if it is moved into a humid environment, but its integrity would not be at risk in most cases.
The lute top in this picture “potato-chipped” 4 mm in the center at 36% r.H.. In order to adapt the new top to the local Winnipeg climate, I will glue the braces for the new top at 35 % r.H. or slightly lower.