I have always left my braced tops sit in my shop for several weeks
before voicing them and then another few weeks before gluing to their
rim. All wood glues take more than a few days to dry to their full and final
hardness so the time has always made sense to me. Because of this cure
time, the braced top can show obvious differences in resonant frequency
and sustain after a week of drying so I allow it before I begin to remove
material from braces.
Once the glue is fully hardened, the joints between the top or back and
their respective bracing parts can present what will be their final
transduction of individual tones to the tone of the system that they are a
part of. It's common knowledge that the braces serve multiple purposes,
especially on the top, to not only provide structural integrity, but also to
transport the vibration created by the strings from the bridge area to as
much of the plate as possible. The goal in calculating and arriving at the
exit points of the four legs of the "X" braces should at least include the
consideration of the location of the nodes or points in the plate's
vibration wave that exhibit an amplitude of zero.
Every top that i brace is under tension or stress while free standing as is
every braced back. That stress contributes to the resonance of the plates
individually and then to the closed, bound body as a system. The effects
of both vibration and reflection can be dramatically enhanced with a little
tension. If you're arching your top or back at all, you are building under
stress, plain and simple. I love the Larson Bros. instruments and have
embraced more than one point of their building philosophy or mentality.
When my tops and backs are fitted to the rim, they lay in place before
clamping and make full contact around the entire perimeter so there is no
stress at the glue joints at the rim themselves, but only in the relationship
between the braces and the plates. It's kind of a "selective stress" build
environment.
A "stress free" build goes out the window once strings are pulled to
pitch on a guitar since the stress applied by them is distributed through
every component of the guitar.
I keep my RH in the entire shop within a percentage point of 45% and
temp with a degree either way of 70 degrees so i've had tops sit there for
more than a year between bracing and gluing without any change in their
shape.
To answer the original question, though.....If you're environment is
consistent, it's not an issue.
Regards,
Kevin Gallagher/Omega Guitars
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