Claudio wrote

>Let me first say that, IMHO, although traditional glue has the advantages we
>all know, most harpsichords assembled with vinyl glue have lasted for
>decades with no glue issues whatsoever.

>IMHO in the kit you refer to, the type of glue is not to blame. In most
>harpsichords the tension of the string is mostly held not by the glue (how
>could a humble glue layer stand almost one tonne of string pull?) but rather
>by the case frames holding the liner in place.

I have to disagree, I think the failure of the glue joint is the primary problem. A well made glue joint ie fresh hide glue and the gluing faces freshly cut or lightly sanded, should hold above all else. In a Ruckers design such as Zuckermann used back then the upper braces work  generally against the liner and bentside  together , on originals   they were always nailed in often with no glue. On later instruments such as Taskin upper braces were often fitted to the liner with blocks on the upper face and therefore acted more as an effective brace to the liner.  

I think the bottom needs to come off the instrument so the screws holding the liner to the bentside need to be checked you may have to put machine bolts and washers through the liner to the outside of the bentside to hold things together filling the gap with glue is more cosmetic then a structural repair you can never replicate the original joint by running in glue and hoping things may hold. If animal glue had been used in the first place there would be a possibility of a partial dissasembly of the case and reglueing but this would be a lot of work and expensive and probably not worth it. 
BTW Titebond and other PVA glues will not stick to a dried layer of themselves, all of the old glue has to be completely removed.

Richard

::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
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 .
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::