> Dennis wrote : ... ten year old kit whose liner seems partially unglued
...
Of course, everything glued with modern glue.
H ow could such an instrument be salvaged? ...
> Tom wrote: ... Goop
> Chris wrote: Loctite ...

Hi Dennis,

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.

Accordingly, the departure of the liner from the case walls has only two
alternative explanations:
(1) The bentside has lost its curvature, either from defective making or
through a serious accident: this is a most infrequent event.
(2) When the instrument was built the case frames were not tightly inserted
against the liner, but just loosely (a common mistake by poorly-trained
amateur makers) or else the wood the case frames were made of is too soft
and has undergone compression. As a consequence, under the pull of the
strings the liner has pushed against the frames and became detached from the
case walls.

Furthermore, you can be in either of two situations: 

(A) The soundboard shows no serious warping, and the tuning is stable (say
for a few hours most notes remain in tune).
This means that the liner, although detached from the bentside, is hold
firmly by the frames. You just have to fill the cracks with any material
such as the one recommended by Tom or Chris.

(B) The soundboard has a serious warp, or else the tuning is unstable
because the liner is "floating" between the frames and the case walls.
In this case, filling will obviously fail to resolve any of the problems.
AFAIK the only solution in this case is the full repair:
- Remove all the strings.
- Unglue and remove the soundboard.
- Remove the liner.
- Clean all the "broken" glue.
- Reinsert the liner and glue it against the bentside and other walls.
- At this stage you will find that the frames fail to reach the liner by
anything between one and a few millimetres. For every frame, fill the space
with hardwood pressed hard (and glued) between the frame and the liner.
 
This procedure worked for me fixing a kit poorly assembled by an amateur: it
has lasted for at lest 30 years, AFAIK.
 
(I would not try the seemingly easier way, leaving the strings in place and
removing the case bottom instead. This in some types of instruments is
difficult, and anyway does not allow to clean the liner glue, to have it
pushed against the bentside and the space between the frames solidly filled
by hardwood. And if you managed to do so, moving the liner while still glued
to the soundboard will produce lots of cracks in the latter.)
 
All the best! Please let us know how the story unfolds!

CDV



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