The description of the Mine109 fortepiano by Elfried Gleim mentions a soundboard thickness of 2.9mm at the gap; As far as I remember  Gerard Tuinman used a thickness of 2.5 mm at the treble and 2.9 at the bass for his copies of the same piano. For my own copy I used an overall thickness of 3.0 mm which was satisfactory, at least to my ears.
best, Habo
On 23 Oct 2016, at 23:17, Marianne Lilian Perez-Robledo <[log in to unmask]> wrote:

> I've got that technical drawing of the Anton Walter fortepiano c. 1795, in the Nüremberg's Germanisches National Museum, drawn by Susanne Witmayer that does not contain measurements of the thickness of the soundboard at all...
> 
> Could someone in the List help me with this information?
> 
> I'm a harpsichord builder and have restored several square pianos here in Buenos Aires. I guess the average thickness may be about 4 mm, but I would like to confirm this with the experience and knowledge of some of you.
> 
> Thank you all in advance
> 
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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 .
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