(Writing from experience) if one does elect to use an automobile as a kiln
prior to gluing in the SB, be aware of the relative humidity in the room
the instrument will live in. If the SB has been sitting in a garage fo a
few days or more, it will already be at a higher RH that you will want, so
you will need to shrink it more than otherwise needed.

Be sure to mark out along the belly rail end of the SB a reference spot,
say 28 inches from the spine side. Make a note of the distance. In any
event avoid shrinking the SB more than about an eighth of an inch OR LESS
across the belly. This process is intended to provide just enough
compression to produce enough crown so the SB doesnt sink to the floor. Too
great a crown under the bridge will lead to tuning stability issues.

I use this process to shrink the SB proir to installing the 8 foot bridge.
In this case I usually aim for 3/16 inch of shrinkage, resulting in about
an eighth inch of crown.

As usual, this is the readers digest version, so caveat emptor...
- D

PS If you have questions or need more detail, email me at
[log in to unmask], and I'll do my wurst. No, best to accommodate your
needs.

On Mon, Jun 11, 2018, 9:46 AM David Pickett <[log in to unmask]> wrote:

> I have read of people leaving the soundboard in a closed car in the
> hot sun before very quickly gluing it up!
>
> David
>
> At 14:46 11-06-18, Michael Bender wrote:
>  >
>  >Dear members,
>  >
>  >this summer I am helping a  young student making her own harpsichord.
>  >She works on a six-foot-Ruckers-style single, 8' 8'. The case has been
>  >finished and we are glueing up the soundboard right now.
>  >
>  >SB material is alpine fir.
>  >
>  >In oder to prevent the finished boards from cracking up, I always
>  >chose cold and dry winter days to work on the SBs of my own ten
> harpsichords.
>  >But the young lady will have to present a playable instrument by
>  >october. (final painting, decorating, the build of a stand - even lids
>  >- may follow later).
>  >
>  >So: Is there any way to dry out the thinned soundboard in summer here
>  >in Germany?
>  >Bright sun?
>  >Sauna?
>  >Ventilation?
>  >
>  >Unfortunately I do not have access to professional gear such as drying
>  >chambers or things like that.
>  >
>  >Greetings from river Rhine
>  >
>  >Michael
>
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::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Note:  opinions  expressed on HPSCHD-L are those of the  individual con-
tributors and not necessarily  those of the list owners  nor of the Uni-
versity of Iowa.  For a brief  summary of list  commands, send mail to
[log in to unmask]  saying  HELP .
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::